Title of Regulation: 16VAC25-50. Boiler and Pressure Vessel Regulations (amending 16VAC25-50-10, 16VAC25-50-20, 16VAC25-50-30, 16VAC25-50-260, 16VAC25-50-280, 16VAC25-50-300, 16VAC25-50-330, 16VAC25-50-360, 16VAC25-50-370, 16VAC25-50-380, 16VAC25-50-430, 16VAC25-50-460, 16VAC25-50-540).

Statutory Authority: § 40.1-51.6 of the Code of Virginia.

Public Hearing Information:

July 27, 2017 - 10 a.m. - South Main Street Centre, 600 East Main Street, 12th Floor Conference Room, Richmond, VA 23219

Public Comment Deadline: September 22, 2017.

Agency Contact: Ed Hilton, Director, Boiler Safety Compliance, Department of Labor and Industry, Main Street Centre, 600 East Main Street, Richmond, VA 23219, telephone (804) 786-3169, FAX (804) 371-2324, or email ed.hilton@doli.virginia.gov.

Basis: The Safety and Health Codes Board is authorized by § 40.1-51 of the Code of Virginia to formulate definitions, rules, regulations, and standards that are designed for the protection of human life and property from the unsafe or dangerous construction, installation, inspection, operation, maintenance, and repair of boilers and pressure vessels in the Commonwealth.

Purpose: The purpose of this proposed regulatory action is to provide increased protection of human life, both employee safety and public safety, and property from the unsafe or dangerous construction, installation, inspection, operation, and repair of boilers and pressure vessels in the Commonwealth of Virginia by complying with the most recent editions of industry required guidance documents.

Substance: The proposed amendments update the regulations to the most recent editions of certain national standards and forms, as listed below:

Standards

Boiler and Pressure Vessel Code, ASME Code, 2015, American Society of Mechanical Engineers (ASME)

ANSI/NB 23, National Board Inspection Code, 2015, National Board of Boiler and Pressure Vessel Inspectors

ASME B31.1, ASME Code for Power Piping, 2014, American National Standards Institute

NFPA 85, Boiler and Combustion Systems Hazards, 2015, National Fire Protection Association (NFPA)

Part CG (General), Part CW (Steam and Waterside Control) and Part CF (Combustion Side Control) Flame Safeguard of ANSI/ASME CSD-1, Controls and Safety Devices for Automatically Fired Boilers, 2012, American Society of Mechanical Engineers

API 510, Pressure Vessel Inspection Code, Maintenance Inspection, Rating, Repair and Alteration, Tenth Edition, May 2014, American Petroleum Institute

Forms

Form R-1, Report of Repair, National Board Inspection Code (NBIC) NB-66 (rev.13 6/25/15)

Form R-2, Report of Alteration, National Board Inspection Code NB-229 (rev.7 11/12/15)

Form R-3, Report of Parts Fabricated By Welding, National Board Inspection Code NB-230 (rev.3 9/24/15)

Form R-4, Report Supplementary Sheet, National Board Inspection Code NB-231 (9/23/15).

Issues: The primary advantages to the public are the use of the latest editions of publications required for use by the boiler and pressure vessel industry and consistency with national references. These changes are deemed necessary to update the proposed regulations to the current editions of ASME, NBIC, and NFPA safety and inspection codes that are incorporated by reference into the Commonwealth's Boiler and Pressure Vessel Rules and Regulations. The most current editions of required documents, which contain the latest technological information, will provide both increased protection of human life (both employee safety and public safety) as well as protecting property from unsafe or dangerous construction, installation, inspection, operation, and repair of boilers and pressure vessels in the Commonwealth of Virginia. Companies that utilize the ASME, NBIC, and NFPA safety and inspection codes for construction or repair are already required to have and work to the latest editions of these codes. The proposed regulation causes no known disadvantages to private citizens or businesses.

The primary advantage for the Commonwealth associated with this proposed regulatory action is the use of the latest editions of the aforementioned publications for consistency with the boiler and pressure vessel industry nationwide. Virginia companies that utilize the ASME, NBIC, and NFPA safety and inspection codes for construction or repair are already required to have and work to the latest editions of these codes. The proposed regulation causes no known disadvantages to the Commonwealth.

Small Business Impact Review Report of Findings: This proposed regulatory action serves as the report of the findings of the regulatory review pursuant to § 2.2-4007.1 of the Code of Virginia.

Department of Planning and Budget's Economic Impact Analysis:

Summary of the Proposed Amendments to Regulation. As the result of a periodic review,¹ the Safety and Health Codes Board (Board) proposes to adopt the most current versions of several documents incorporated by reference that set out boiler and pressure vessel standards, as well as several forms.

Result of Analysis. The benefits likely exceed the costs for all proposed changes.

Estimated Economic Impact. The Board proposes to adopt the following most recent published editions of safety and inspection codes already incorporated by reference into the regulation:

• 2015 Boiler and Pressure Vessel Code, ASME Code, American Society of Mechanical

Engineers;

• ANSI/NB 23, 2015 National Board Inspection Code, National Board of Boiler and

Pressure Vessel Inspectors;

• ASME B31.1, ASME Code for Power Piping, American National Standards Institute,

2014;

• NFPA 85 Boiler and Combustion Systems Hazards, 2015 Edition, National Fire

Protection Association;

• Part CG (General), Part CW (Steam and Waterside Control) and Part CF (Combustion

Side Control) Flame Safeguard of ANSI/ASME CSD-1, Controls and Safety Devices for

Automatically Fired Boilers, 2012, American Society of Mechanical Engineers; and

• API510, Pressure Vessel Inspection Code, Maintenance Inspection, Rating, Repair and

Alteration, Tenth Edition, May 2014, American Petroleum Institute.

These documents have not been updated in the regulation since 2008. The Department of Labor and Industry (DOLI) reports that the difference between the current and updated standards reflect the most recent technology available and will provide increased protection to human life and property. For the most part the updated standards do not increase costs for affected firms. The new standards specifically would require that new businesses with carbon dioxide (CO₂) tanks for liquid beverage dispensers have signs and CO₂ meters/alarms.²  

CO₂ storage safety meters/alarms protect customers, employees and emergency first-responders near stored carbon dioxide. A leak anywhere in a stored CO₂ delivery system can quickly fill an enclosed area with potentially dangerous CO₂ levels. Higher concentrations of CO₂ can affect respiratory function and cause excitation followed by depression of the central nervous system. A high concentration can displace oxygen in the air. If less oxygen is available to breathe, symptoms such as rapid breathing, rapid heart rate, clumsiness, emotional upsets and fatigue can result. As less oxygen becomes available, nausea and vomiting, collapse, convulsions, coma and death can occur. Lack of oxygen can cause permanent damage to organs including the brain and heart.³

CO₂ storage safety meters/alarms (and signage) that meet the proposed standards would cost approximately $500.⁴ Given the potential health risks of undetected CO₂ as described above, the benefits of the proposed requiring of CO₂ storage safety meters/alarms and informative signage likely exceeds the cost.

Businesses and Entities Affected. The proposed amendments potentially affect businesses that manufacture, repair, own, or operate boilers or pressure vessels. DOLI estimates that there are approximately 25,000 small businesses among these types of firms. New businesses with CO₂ tanks for liquid beverage dispensers, such as restaurants, convenience stores, breweries, etc., would be particularly affected.

Localities Particularly Affected. The proposed amendments do not disproportionately affect particular localities.

Projected Impact on Employment. The proposed amendments would likely increase the demand for CO₂ storage safety meters/alarms. The firms that manufacture and/or sell them may commensurately increase employment.

Effects on the Use and Value of Private Property. The proposed amendment does not significantly affect the use and value of private property.

Real Estate Development Costs. The proposed amendments do not affect real estate development costs.

Small Businesses:

Definition. Pursuant to § 2.2-4007.04 of the Code of Virginia, small business is defined as "a business entity, including its affiliates, that (i) is independently owned and operated and (ii) employs fewer than 500 full-time employees or has gross annual sales of less than $6 million."

Costs and Other Effects. The proposed amendments require that new small businesses that have CO₂ tanks for liquid beverage dispensers have signs and CO₂ meters/alarms. This would increase costs for such small firms (restaurants, convenience stores, breweries, etc.) by about $500 for each area that has CO₂ tanks for liquid beverage dispensers.⁵

Alternative Method that Minimizes Adverse Impact. There is no apparent alternative method that meets the intended safety goals at a lower cost.

Adverse Impacts:

Businesses. The proposed amendments require that new businesses that have CO₂ tanks for liquid beverage dispensers have signs and CO₂ meters/alarms. This would increase costs for such firms (restaurants, convenience stores, breweries, etc.) by about $500 for each area that has CO₂ tanks for liquid beverage dispensers.⁶

Localities. The proposed amendments do not adversely affect localities.

Other Entities. The proposed amendments do not adversely affect other entities.

¹ http://townhall.virginia.gov/l/ViewPReview.cfm?PRid=1496

² Virginia companies that utilize ASME, NBIC, and NFPA standards are already required to comply with the proposed standards.

³ Source: Canadian Centre for Occupational Health and Safety: https://www.ccohs.ca/oshanswers/chemicals/chem_profiles/carbon_dioxide.html

⁴ https://www.co2meter.com/products/remote-co2-storage-safety-alarm-ip65 viewed on April 20, 2017.

⁵ Ibid

⁶ Ibid

Agency's Response to Economic Impact Analysis: The Department of Labor and Industry has no additional comment in response to the economic impact analysis.

Summary:

The proposed regulatory action incorporates the most recent editions of nationally recognized model codes and forms produced by the American Society of Mechanical Engineers, the National Board of Boiler and Pressure Vessel Inspectors, and other standard-writing groups into the safety and inspection regulations for boilers and pressure vessels.

Part I
Definitions

16VAC25-50-10. Definitions.

The following words and terms when used in this chapter shall have the following meanings, unless the context clearly indicates otherwise:

"Act" means the Boiler and Pressure Vessel Safety Act, Chapter 3.1 (§ 40.1-51.5 et seq.) of Title 40.1 of the Code of Virginia.

"Alteration" means any change in the item described on the original Manufacturers' Data Report which affects the pressure containing capability of the boiler or pressure vessel. Non-physical changes, such as an increase in the maximum allowable working pressure (internal or external) or design temperature of a boiler or pressure vessel, shall be considered an alteration. A reduction in minimum temperature such that additional mechanical tests are required shall also be considered an alteration.

"ANSI/ASME CSD-1" means ASME CSD-1-2012, Controls and Safety Devices for Automatically Fired Boilers, 2012 Edition, American Society of Mechanical Engineers.

"API-510" means API-510, Pressure Vessel Inspection Code: In-Service Inspection, Rating, Repair, and Alteration, Tenth Edition, May 2014, American Petroleum Institute.

"Approved" means acceptable to the board, commissioner or chief inspector as applicable.

"ASME B31" means ASME B31.1-2014, Power Piping, an International Piping Code, The American Society of Mechanical Engineers.

"ASME Code" means the Boiler and Pressure Vessel Code of the American Society of Mechanical Engineers approved and adopted by the governing council of such society and approved and adopted by the board.

"Authorized inspection agency" means one of the following:

a. A department or division established by a state, commonwealth or municipality of the United States, or a province of Canada, which has adopted one or more sections of the Boiler and Pressure Vessel Code of the ASME Code and whose inspectors hold valid commissions with the National Board of Boiler and Pressure Vessel Inspectors; or equivalent qualifications as defined and set forth in 16VAC25-50-50 and 16VAC25-50-70;

b. An inspection agency of an insurance company which is authorized (licensed) to write boiler and pressure vessel insurance in those jurisdictions which have examined the agency's inspectors to represent such jurisdictions as is evident by the issuance of a valid certificate of competency to the inspector;

c. An owner-user inspection agency as defined in this section; or

d. A contract fee inspector.

"Board" means the Virginia Safety and Health Codes Board.

"Boiler" means a closed vessel in which water is heated, steam is generated, steam is superheated, or any combination of them, under pressure or vacuum for use externally to itself by the direct application of heat. The term "boiler" shall include fired units for heating or vaporizing liquids other than water where these units are separate from processing systems and are complete within themselves.

"Certificate of competency" means a certificate issued by the commissioner to a person who has passed the prescribed examination as provided in 16VAC25-50-50. See §§ 40.1-51.9 and 40.1-51:9:1 40.1-51.9:1 of the Act.

"Certificate inspection" means an inspection, the report of which is used by the chief inspector to decide whether or not a certificate, as provided for in § 40.1-51.10 of the Act may be issued. This certificate inspection shall be an internal inspection when required; otherwise, it shall be as complete an inspection as possible.

"Chief inspector" means the chief boiler and pressure vessel inspector of the Commonwealth.

"Commission, National Board" means the commission issued by the National Board to a holder of a Certificate of Competency for the purpose of conducting inspections in the Commonwealth in accordance with the National Board Bylaws and this chapter. The employer must submit the inspector's application to the National Board for a commission.

"Commissioner" means the Commissioner of the Department of Labor and Industry.

"Commonwealth inspector" means any agent appointed by the commissioner under the provisions of § 40.1-51.9 of the Act.

"Condemned boiler or pressure vessel" means a boiler or pressure vessel that has been inspected and declared unsafe for use or disqualified by legal requirements and to which a stamping or marking designating its condemnation has been applied by the chief or commonwealth inspector.

"Current edition of the ASME Code" means the 2015 Edition of the ASME Code, which has been adopted by the Safety and Health Codes Board.

"Department" means the Department of Labor and Industry.

"Division" means the Boiler Safety Enforcement Division of the Department of Labor and Industry.

"Electric boiler" means a boiler in which the source of heat is electricity.

"Examining board" means persons appointed by the chief inspector to monitor examinations of inspectors.

"Existing installation" means and includes any boiler or pressure vessel constructed, installed, placed in operation or contracted for before July 1, 1974.

"External inspection" means an inspection of the exterior of the boiler or pressure vessel and its appliances when the item is in operation.

"Heating boiler" means a steam or vapor boiler operating at pressures not exceeding 15 psig, or a hot water boiler operating at pressures not exceeding 160 psig or temperature not exceeding 250°F at or near the boiler outlet.

"High-pressure, high-temperature water boiler" means a water boiler operating at pressures exceeding 160 psig or temperatures exceeding 250°F at or near the boiler outlet.

"Hobby boiler" means a steam boiler which serves no commercial purpose and is used solely for hobby or display and operated solely for the enjoyment of the owner.

"Hot water supply boiler" means a boiler furnishing hot water to be used externally to itself at pressures not exceeding 160 psig or temperatures not exceeding 250°F at or near the boiler outlet, with the exception of boilers which are directly fired by oil, gas or electricity where none of the following limitations are is exceeded:

a. Heat input of 200,000 BTU per hour;

b. Water temperature of 210°F; or

c. Nominal water containing capacity of 120 gallons.

"Hot water supply storage tanks" means those heated by steam or any other indirect means where any one of the following limitations are is exceeded:

a. Heat input of 200,000 BTU per hour;

b. Water temperature of 210°F; or

c. Nominal water containing capacity of 120 gallons.

"Inspection certificate" means a certificate issued by the chief inspector for the operation of a boiler or pressure vessel.

"Inspector" means the chief inspector, commonwealth inspector or special inspector.

"Internal inspection" means a complete examination of the internal and external surfaces of a boiler or pressure vessel and its appliances while it is shut down and manhole plates, handhole plates or other inspection openings removed.

"Lap seam crack" means a failure in a lap joint extending parallel to the longitudinal joint and located either between or adjacent to rivet holes.

"Miniature boiler" means any boiler which does not exceed any one of the following limits:

a. 16 inches inside diameter of shell;

b. 20 square feet heating surface;

c. 5 cubic feet gross volume, exclusive of casing and insulation; or

d. 100 psig maximum allowable working pressure.

"National Board" means the National Board of Boiler and Pressure Vessel Inspectors, 1055 Crupper Avenue, Columbus, OH 43229, whose membership is composed of the chief inspectors of government jurisdictions who are charged with the enforcement of the provisions of the ASME Code.

"National Board Inspection Code" means the manual for boiler and pressure vessel inspectors published by the National Board. Copies of this code may be obtained from the National Board NB-23, the National Board Inspection Code, 2015 Edition, The National Board of Boiler Pressure Vessel Inspectors.

"National Fire Protection Association No. 85" means the NFPA^® 85, Boiler and Combustion Systems Hazards Code, 2015 Edition, National Fire Protection Association.

"New boiler or pressure vessel installation" means all boilers or pressure vessels constructed, installed, placed in operation or contracted for after July 1, 1974.

"NFPA" means the National Fire Protection Association.

"Nonstandard boiler or pressure vessel" means a boiler or pressure vessel that does not bear the stamp of Commonwealth of Virginia, the ASME stamp or the National Board stamp when applicable.

"Owner or user" means any person, partnership, firm or corporation who is legally responsible for the safe operation of a boiler or pressure vessel within the Commonwealth.

"Owner-user inspection agency" means any person, partnership, firm or corporation registered with the chief inspector and approved by the board as being legally responsible for inspecting pressure vessels which they operate in this Commonwealth.

"Portable boiler" means an internally fired boiler which is primarily intended for temporary location and whose construction and usage permit it to be readily moved from one location to another.

"Power boiler" means a boiler in which steam or other vapor is generated at a pressure of more than 15 psig.

"Pressure vessel" means a vessel in which the pressure is obtained from an external source, or by the application of heat from an indirect source, or from a direct source, other than those boilers defined in Part I (16VAC25-50-10 et seq.) of this chapter.

"PSIG" means pounds per square inch gauge.

"R Certificate of Authorization" means an authorization issued by the National Board for the repair and alteration of boilers and pressure vessels.

"Reinstalled boiler or pressure vessel" means a boiler or pressure vessel removed from its original setting and reinstalled at the same location or at a new location.

"Repair" means work necessary to return a boiler or pressure vessel to a safe and satisfactory operating condition, provided there is no deviation from the original design.

"Secondhand boiler or pressure vessel" means a boiler or pressure vessel which has changed both location and ownership since the last certificate inspection.

"Special inspector" means an inspector holding a Virginia Certificate of Competency, and who is regularly employed by an insurance company authorized (licensed) to write boiler and pressure vessel insurance in this Commonwealth, an inspector continuously employed by any company operating pressure vessels in this Commonwealth used or to be used by the company, or a contract fee inspector.

"Standard boiler or pressure vessel" means a boiler or pressure vessel which bears the stamp of the Commonwealth of Virginia, the ASME Code stamp and the National Board stamp when applicable.

"Underwriters' Laboratories" means Underwriters' Laboratories, Inc., 333 Pfingsten Road, Northbrook, Illinois 60062, which is a nonprofit, independent organization testing for public safety. It maintains and operates laboratories for the examination and testing of devices, systems, and materials to determine their relation to life, fire, casualty hazards and crime prevention.

"VR Certificate of Authorization" means an authorization issued by the National Board for the repair of pressure relief valves.

"Water heater" means a vessel used to supply: (i) potable hot water; or (ii) both space heat and potable water in combination which is directly heated by the combustion of fuels, electricity, or any other source and withdrawn for use external to the system at pressures not to exceed 160 psi or temperatures of 210°F. This term also includes fired storage water heaters defined by the Virginia Uniform Statewide Building Code as a "water heater."

Part II
Administration

16VAC25-50-20. Minimum construction standards for boilers and pressure vessels.

A. Boilers and pressure vessels to be installed for operation in this Commonwealth shall be designed, constructed, inspected, stamped and installed in accordance with the applicable ASME Boiler and Pressure Vessel Code including all addenda and applicable code case(s) cases, other international construction standards which are acceptable to the chief inspector, and this chapter.

B. Boilers and pressure vessels shall bear the National Board stamping, except cast iron boilers and UM vessels. A copy of the Manufacturers' Data Report, signed by the manufacturer's representative and the National Board commissioned inspector, shall be filed by the owner or user with the chief inspector prior to its operation in the Commonwealth.

C. Pressure piping -- (including welded piping) -- Piping external to power boilers extending from the boiler to the first stop valve of a single boiler, and to the second stop valve in a battery of two or more boilers is subject to the requirements of the current edition of the ASME Power Boiler Code, Section I and the design, fabrication, installation and testing of the valves and piping shall be in conformity with the applicable paragraphs of the current edition of the ASME Code, Section I. Applicable ASME data report forms for this piping shall be furnished by the owner to the chief inspector. Construction rules for materials, design, fabrication, installation and testing both for the boiler external piping and the power piping beyond the valve or valves required by the current edition of the ASME Power Boiler Code, Section I, are referenced in ANSI ASME B31.1, Power piping, and the code ASME Code.

D. Boilers and pressure vessels brought into the Commonwealth and not meeting code ASME Code requirements shall not be operated unless the owner/user is granted a variance in accordance with § 40.1-51.19 of the Act.

The request for variance shall include all documentation related to the boiler or pressure vessel that will provide evidence of equivalent fabrication standards, i.e., design specification, calculations, material specifications, detailed construction drawings, fabrication and inspection procedures and qualification records, examination, inspection and test records, and any available manufacturers' data report.

In order to facilitate such a variance approval, the submission of documentation, in the English language and in current U.S. standard units of measure would be helpful. The following list of documents, while not all inclusive, would be useful in providing evidence of safety equivalent to ASME Code construction:

1. List of materials used for each pressure part;

2. The design calculations to determine the maximum allowable working pressure in accordance with the ASME Boiler and Pressure Vessel Code, applicable section, edition and addenda;

3. The design code used and the source of stress values for the materials used in the design calculations;

4. The welding procedures used and the qualification records for each procedure;

5. The material identification for each type of welding material used;

6. The performance qualification records for each welder or welding operator used in the construction of the boiler or pressure vessel;

7. The extent of any nondestructive examination (NDE) performed and the qualification records of NDE operators;

8. Record of final pressure test signed by a third party inspector;

9. Name and organization of the third party inspection agency;

10. A certification from a licensed professional engineer stating that the boiler or pressure vessel has been constructed to a standard providing equivalent safety to that of the ASME Boiler and Pressure Vessel Code. A signature, date and seal of the certifying engineer is are required;

11. Where applicable, a matrix of differences between the actual construction of the boiler or pressure vessel for which a variance is requested and a similar boiler or pressure vessel that is code ASME Code stamped; and

12. Where applicable, a letter from an insurance company stating that it will insure the boiler or pressure vessel.

After notification of a violation of these rules and regulations this chapter, an owner/user desiring a variance shall submit a request for variance within 30 days.

The chief inspector shall respond to any request for a variance within 30 days of receipt of all required documentation, and shall submit a recommendation to the commissioner, who will make the decision on the variance.

E. Before secondhand equipment is installed, application for permission to install shall be filed by the owner or user with the chief inspector and approval obtained.

F. Electric boilers, subject to the requirements of the Act and this chapter, shall bear the Underwriters' Laboratories label on the completed unit or assembly by the manufacturer. This label shall be in addition to the code symbol stamping requirements of the ASME Code and the National Board.

16VAC25-50-30. Frequency of inspections of boilers and pressure vessels.

A. Power boilers and high-pressure, high-temperature water boilers shall receive an annual internal inspection for certification. Such boilers shall also receive, where possible, an annual external inspection, given while under representative operating conditions.

B. Heating boilers shall receive a certificate inspection biennially.

1. Steam boilers shall receive an internal inspection where construction permits.

2. Water boilers shall receive an external inspection with an internal inspection at the discretion of the inspector where construction permits.

C. Except as provided for in subsection E of this section, pressure vessels subject to internal corrosion shall receive a certificate inspection biennially. This inspection shall be an internal inspection conducted at the discretion of the inspector where construction permits.

D. Except as provided for in subsection E of this section, pressure vessels not subject to internal corrosion shall receive a certificate inspection biennially. This inspection shall be an external inspection, with an internal inspection conducted at the discretion of the inspector where construction permits.

E. Pressure vessels that are under the supervision of an authorized owner-user inspection agency shall be inspected at intervals in a manner as agreed upon between the Commissioner and that agency.

F. Boiler and pressure vessel components of nuclear power plants, that are included in the Act, shall be inspected as provided by Section XI of the ASME Boiler and Pressure Vessel Code, Section XI.

G. Based upon documentation of such actual service conditions by the owner or user of the operating equipment, the Commissioner may permit variations in the inspection requirements as provided in the Act.

16VAC25-50-260. Removal of safety appliances.

A. No person shall attempt to remove or do any work on any safety appliance prescribed by this chapter while a boiler or pressure vessel is in operation, except as provided in applicable sections of the current edition of the ASME Code. Should any of these appliances be removed for repair during an outage of a boiler or pressure vessel, they must be reinstalled and in proper working order before the object is again placed in service.

B. No person shall load the safety valve or valves in any manner to maintain a working pressure in excess of that stated on the inspection certificate.

16VAC25-50-280. Requirements for new installations.

A. No boiler or pressure vessel shall be installed in this Commonwealth unless it has been constructed, inspected and stamped as provided in Part II, 16VAC25-50-20 except:

1. Those exempt by the Act;

2. Those outlined in Part II, 16VAC25-50-20 D; and

3. Those existing boilers and pressure vessels which that are to be reinstalled.

B. All new boiler and pressure vessel installations, including reinstalled and secondhand boilers and pressure vessels, shall be installed in accordance with the requirements of the current edition of the ASME Code and this chapter.

C. A boiler or pressure vessel constructed equivalent to ASME Code standards, or having the standard stamping of another state that has adopted a standard of construction equivalent to the standard of this Commonwealth, may be accepted by the chief inspector. The person desiring to install the boiler or pressure vessel shall make application for the installation prior to construction and shall file the Manufacturers' Data Report for the boiler or pressure vessel with the chief inspector following construction and prior to installation.

D. The stamping shall not be concealed by insulation or paint and shall be exposed at all times unless a suitable record is kept of the location of the stamping so that it may be readily uncovered at any time this may be desired.

16VAC25-50-300. Return loop connection.

The return water connections to all low-pressure, steam heating boilers supplying a gravity return heating system shall be arranged to form a loop so that the water cannot be forced out of the boiler below the safe water level. This connection, known as a "return pipe loop connection," is shown in Section IV, the current edition of the ASME Heating Boiler Code, Section IV.

16VAC25-50-330. Operation.

The current edition of the ASME Code, Section VII, Recommended Rules for Care of Power Boilers, Section VII, and the current edition of the ASME Code, Section VI, Recommended Rules for Care of Heating Boilers, Section VI, of the ASME Code, shall be used as a guide for proper and safe operating practices.

Part III
Existing Installations

16VAC25-50-360. Power and high-pressure, high-temperature water boilers.

A. Age limit of existing boilers.

1. The age limit of any boiler of nonstandard construction, installed before July 1, 1974, other than one having a riveted, longitudinal lap joint, shall be 30 years; however, any boiler passing a thorough internal and external inspection, and not displaying any leakage or distress under a hydrostatic pressure test of 1-1/2 times the allowable working pressure held for at least 30 minutes, may be continued in operation without reduction in working pressure. The age limit of any boiler having riveted, longitudinal, lap joints and operating at a pressure in excess of 50 psig shall be 20 years. This type of boiler, when removed from an existing setting, shall not be reinstalled for a pressure in excess of 15 psig. A reasonable time for replacement, not to exceed one year, may be given at the discretion of the chief inspector.

2. The shell or drum of a boiler in which a typical lap seam crack is discovered along a longitudinal riveted joint for either butt or lap joints shall be permanently removed from service.

3. The age limit of boilers of standard construction, installed before July 1, 1974, shall be determined from the results of a thorough internal and external inspection by an authorized inspector and the application of an appropriate pressure test. Hydrostatic test pressure shall be 1-1/2 times the allowable working pressure and maintained for 30 minutes. The boiler may be continued in service at the same working pressure provided there is no evidence of leakage or distress under these test conditions.

4. The minimum temperature of the water used for the hydrostatic test of low-pressure boilers and pressure vessels shall be 60°F. The minimum temperature of the water used for the hydrostatic test of power boilers shall be 70°F or ambient whichever is greater.

B. The maximum allowable working pressure for standard boilers shall be determined in accordance with the applicable provisions of the edition of the ASME Code under which they were constructed and stamped.

C. 1. The maximum allowable working pressure on the shell of a nonstandard boiler shall be determined by the strength of the weakest section of the structure, computed from the thickness of the plate, the tensile strength of the plate, the efficiency of the longitudinal joint or tube ligaments, the inside diameter of the weakest course and the factor of safety allowed by this chapter.

	TStE	=	Maximum allowable working pressure, psi
	RFS

where:

TS = ultimate tensile strength of shell plates, psi

t = minimum thickness of shell plate, in weakest course, inches

E = efficiency of longitudinal joint:

For tube ligaments, E shall be determined by the rules in the ASME Code, Section I of the ASME Code for Power Boilers. For riveted joints, E shall be determined by the rules in the applicable edition of the ASME Code. For seamless construction, E shall be considered 100%.

R = inside radius of the weakest course of the shell, in inches

FS = factor of safety permitted.

2. Tensile strength. When the tensile strength of steel or wrought iron shell plates is not known, it shall be taken as 55,000 psi.

3. Crushing strength of mild steel. The resistance to crushing of mild steel shall be taken at 95,000 psi of cross-sectional area.

4. Strength of rivets in shear. When computing the ultimate strength of rivets in shear, the following values, in pounds per square inch, of the cross-sectional area of the rivet shank shall be used.

	PSI
Iron rivets in single shear	38,000
Iron rivets in double shear	76,000
Steel rivets in single shear	44,000
Steel rivets in double shear	88,000

When the diameter of the rivet holes in the longitudinal joints of a boiler is not known, the diameter and cross-sectional area of rivets, after driving, may be selected from Table 1, or as ascertained by cutting out one rivet in the body of the joint.

TABLE 1 SIZES OF RIVETS BASED ON PLATE THICKNESS (in inches)
Plate of Thickness	Rivet Diameter after Driving
1/4	11/16
9/32	11/16
5/16	3/4
11/32	3/4
3/8	13/16
13/32	13/16
7/16	15/16
15/32	15/16
1/2	15/16
9/16	1-1/16
5/8	1-1/16

5. Factors of safety. The following factors of safety shall be increased by the inspector if the condition and safety of the boiler demand it:

a. The lowest factor of safety permissible on existing installations shall be 4.5 for vessels built prior to January 1, 1999. For vessels built on or after January 1, 1999, the factor of safety may be 4.0. Horizontal-return-tubular boilers having continuous longitudinal lap seams more than 12 feet in length, shall have a factor of safety of eight. When this type of boiler is removed from its existing setting, it shall not be reinstalled for pressures in excess of 15 psig.

b. Reinstalled or secondhand boilers shall have a minimum factor of safety of six when the longitudinal seams are of lap-riveted construction, and a minimum factor of safety of five when the longitudinal seams are of butt-strap and double-strap construction.

D. Cast-iron headers and mud drums. The maximum allowable working pressure on a water tube boiler, the tubes of which are secured to cast iron or malleable-iron headers, or which have cast iron mud drums, shall not exceed 160 psig.

E. Pressure on cast iron boilers. The maximum allowable working pressure for any cast iron boiler, except hot water boilers, shall be 15 psig.

F. Safety valves.

1. The use of weighted-lever safety valves, or safety valves having either the seat or disk of cast iron, shall be prohibited. Valves of this type shall be replaced by direct, spring-loaded, pop-type valves that conform to the requirements of the current edition of the ASME Code, Section I.

2. Each boiler shall have at least one safety valve, and, if it has more than 500 square feet of water-heating surface or an electric power input of more than 500 kilowatts, it shall have two or more safety valves.

3. The valve or valves shall be connected to the boiler, independent of any other steam connection, and attached as close as possible to the boiler without unnecessary intervening pipe or fittings. Where alteration is required to conform to this requirement, the chief inspector shall allow the owner or user reasonable time in which to complete the work.

4. No valves of any description shall be placed between the safety valve and the boiler nor on the escape pipe, if used, between the safety valve and the atmosphere, except as provided by applicable sections of the current edition of the ASME Code. When an escape pipe is used, it shall be at least full size of the safety-valve discharge and fitted with an open drain to prevent water lodging in the upper part of the safety valve or escape pipe. When an elbow is placed on a safety valve escape pipe, it shall be located close to the safety-valve outlet or the escape pipe shall be anchored and supported securely. All safety valve discharges shall be located or piped as not to endanger persons working in the area.

5. The safety-valve capacity of each boiler shall be so that the safety valve or valves will discharge all the steam that can be generated by the boiler without allowing the pressure to rise more than 6.0% above the highest pressure to which any valve is set, and in no case to more than 6.0% above the maximum allowable working pressure.

6. One or more safety valves on every boiler shall be set at or below the maximum allowable working pressure. The remaining valves may be set within a range of 3.0% above the maximum allowable working pressure, but the range of setting of all the safety valves on a boiler shall not exceed 10% of the highest pressure to which any valve is set.

7. When two or more boilers, operating at different pressures and safety valve settings, are interconnected, the lower pressure boilers or interconnected piping shall be equipped with safety valves of sufficient capacity to prevent overpressure, considering the maximum generating capacity of all boilers.

8. In those cases where the boiler is supplied with feedwater directly from water mains without the use of feeding apparatus (not to include return traps), no safety valve shall be set at a pressure higher than 94% of the lowest pressure obtained in the supply main feeding the boiler.

9. The relieving capacity of the safety valves on any boiler shall be checked by one of the three following methods and, if found to be insufficient, additional valves shall be provided:

a. By making an accumulation test, which consists of shutting off all other steam-discharge outlets from the boiler and forcing the fires to the maximum. The safety-valve capacity shall be sufficient to prevent a rise of pressure in excess of 6.0% of the maximum allowable working pressure. This method shall not be used on a boiler with a superheater or reheater.

b. By measuring the maximum amount of fuel that can be burned and computing the corresponding evaporative capacity (steam-generating capacity) upon the basis of the heating value of this fuel. These computations shall be made as outlined in the appendix of the current edition of the ASME Code, Section I.

c. By measuring the maximum amount of feedwater that can be evaporated.

When either of the methods (b or c) outlined in this subdivision is employed, the sum of the safety-valve capacities shall be equal to or greater than the maximum evaporative capacity (maximum steam-generating capacity) of the boiler.

10. The relieving capacity of safety valves for forced-flow steam generators shall be in accordance with the requirements of Section I the current edition of the ASME Boiler Code, Section I.

11. Safety valves and safety relief valves requiring repair shall be replaced with a new valve or repaired by the original manufacturer, its authorized representative or the holder of a "VR" Stamp.

G. Boiler feeding.

1. Each boiler shall have a feed supply which that will permit it to be fed at any time while under pressure.

2. A boiler having more than 500 square feet of water-heating surface shall have at least two means of feeding, one of which shall be an approved feed pump or injector. A source of feed directly from water mains at a pressure 6.0% greater than the set pressure of the safety valve with the highest setting may be considered one of the means. As provided in the current edition of the ASME Power Boiler Code, Section I, boilers fired by gaseous, liquid or solid fuel in suspension may be equipped with a single means of feeding water provided means are furnished for the immediate shutoff of heat input if the water feed is interrupted.

3. The feedwater shall be introduced into the boiler in a manner so that it will not be discharged close to riveted joints of shell or furnace sheets, or directly against surfaces exposed to products of combustion, or to direct radiation from the fire.

4. The feed piping to the boiler shall be provided with a check valve near the boiler and a valve or cock between the check valve and the boiler. When two or more boilers are fed from a common source, there shall also be a valve on the branch to each boiler between the check valve and source of supply. Whenever a globe valve is used on feed piping, the inlet shall be under the disk of the valve.

5. In all cases where returns are fed back to the boiler by gravity, there shall be a check valve and stop valve in each return line, the stop valve to be placed between the boiler and the check valve, and both shall be located as close to the boiler as is practicable. No stop valves shall be placed in the supply and return pipe connections of a single boiler installation.

6. Where deaerating heaters are not employed, the temperature of the feedwater shall not be less than 120°F to avoid the possibility of setting up localized stress. Where deaerating heaters are employed, the minimum feedwater temperature shall not be less than 215°F so that dissolved gases may be thoroughly released.

H. Water level indicators.

1. Each boiler shall have at least one water gauge glass installed and located so that the lowest visible part of the water glass shall be at least two inches above the lowest permissible water level, at which level there will be no danger of overheating any part of the boiler when in operation at that level; except as provided by the current edition of the ASME Code.

2. No outlet connections (except for damper regulator, feedwater regulator, low-water fuel cutout, drain, steam gauges, or such apparatus that does not permit the escape of an appreciable amount of steam or water from it) shall be placed on the piping that connects the water column to the boiler. The water column shall be provided with a valved drain of at least 3/4 inch pipe size; the drain is to be piped to a safe location.

3. When the direct reading of gauge glass water level is not readily visible to the operator in his working area dependable indirect indications shall be provided utilizing remote level indicators or equipment to transmit the gauge glass image. When remote level indication is provided for the operator instead of the gauge glass, the minimum level reference shall be clearly marked.

I. Steam gauges.

1. Each steam boiler shall have a steam gauge, with dial range not less than 1-1/2 times the maximum allowable working pressure, connected to the steam space or to the steam connection to the water column. The steam gauge shall be connected to a siphon or equivalent device of sufficient capacity to keep the gauge tube filled with water and arranged so that the gauge cannot be shut off from the boiler except by a cock with a tee or lever handle placed in the pipe near the gauge. The handle of the cock shall be parallel to the pipe in which it is located when the cock is open.

2. When a steam gauge connection longer than eight feet becomes necessary, a shutoff valve may be used near the boiler provided the valve is of the outside-screw-and-yoke type and is locked open. The line shall be of ample size with provision for free blowing.

3. Each boiler shall be provided with a test gauge connection and suitable valving for the exclusive purpose of attaching a test gauge so that the accuracy of the boiler steam gauge may be ascertained while the boiler is in operation.

J. Stop valves.

1. Except for a single-boiler, prime-mover installation, each steam outlet from a boiler (except safety valve and water column connections) shall be fitted with a stop valve located as close as practicable to the boiler.

2. In a single-boiler, prime-mover installation the steam stop valve may be omitted provided the prime-mover throttle valve is equipped with an indicator to show whether the valve is open or closed and is designed to withstand the required hydrostatic pressure test of the boiler.

3. When a stop valve is so located that water can accumulate, ample drains shall be provided. The drainage shall be piped to a safe location and shall not be discharged on the top of the boiler or its setting.

4. When boilers provided with manholes are connected to a common steam main, the steam connection from each boiler shall be fitted with two stop valves having an ample free-blow drain between them. The discharge of the drain shall be visible to the operator and shall be piped clear of the boiler setting. The stop valves shall consist preferably of one automatic nonreturn valve (set next to the boiler) and a second valve of the outside-screw-and-yoke type.

K. Blowoff connection.

1. The construction of the setting around each blowoff pipe shall permit free expansion and contraction. Careful attention shall be given to the problem of sealing these setting openings without restricting the movement of the blowoff piping.

2. All blowoff piping, when exposed to furnace heat, shall be protected by firebrick or other heat-resisting material constructed so that the piping may be inspected.

3. Each boiler shall have a blowoff pipe, fitted with a valve or cock, in direct connection with the lowest water space. Cocks shall be of the gland or guard type and suitable for the pressure allowed. The use of globe valves shall not be permitted. Where the maximum allowable working pressure exceeds 100 psig, each blowoff pipe shall be provided with two valves or a valve and cock; however only one valve need be provided for forced-flow steam generators with no fixed steam and waterline;, high-temperature water boilers, and those used for traction or portable purposes with less than 100 gallons normal water content.

4. Blowoff piping shall comply with the requirements of the current edition of the ASME Code, Section I, and ANSI ASME B31.1, from the boiler to the valve or valves, and shall be run full size without use of reducers or bushings. All piping shall be steel. Galvanized steel pipe and fittings shall not be used for blowoff piping.

5. All fittings between the boiler and blowoff valve shall be of steel. In case of renewal of blowoff pipe or fittings, they shall be installed in accordance with this chapter for new installations.

L. Repairs and renewals of boiler fittings and appliances. Whenever repairs are made to fittings or appliances or it becomes necessary to replace them, such repairs or replacements shall comply with the requirements for new installations.

M. Each automatically fired steam boiler or system of commonly connected steam boilers shall have at least one steam pressure control device that will shut off the fuel supply to each boiler or system of commonly connected boilers when the steam pressure reaches a preset maximum operating pressure. In addition, each individual automatically fired steam boiler shall have a high steam pressure limit control that will prevent generation of steam pressure in excess of the maximum allowable working pressure.

N. Conditions not covered by this chapter. All cases not specifically covered by this chapter shall be treated as new installations pursuant to 16VAC25-50-280 or may be referred to the chief inspector for instructions concerning the requirements.

16VAC25-50-370. Heating boilers.

A. Standard boilers. The maximum allowable working pressure of standard boilers shall in no case exceed the pressure indicated by the manufacturer's identification stamped or cast on the boiler or on a plate secured to it.

B. Nonstandard riveted boilers. The maximum allowable working pressure on the shell of a nonstandard riveted heating boiler shall be determined in accordance with 16VAC25-50-360 C covering existing installations, power boilers, except that in no case shall the maximum allowable working pressure of a steam heating boiler exceed 15 psig, or a hot water boiler exceed 160 psig or 250°F temperature.

C. Nonstandard welded boilers. The maximum allowable working pressure of a nonstandard steel or wrought iron heating boiler of welded construction shall not exceed 15 psig for steam. For other than steam service, the maximum allowable working pressure shall be calculated in accordance with Section IV of the ASME Code, Section IV.

D. Nonstandard cast iron boilers.

1. The maximum allowable working pressure of a nonstandard boiler composed principally of cast iron shall not exceed 15 psig for steam service or 30 psig for hot water service.

2. The maximum allowable working pressure of a nonstandard boiler having cast iron shell or heads and steel or wrought iron tubes shall not exceed 15 psig for steam service or 30 psig for hot water service.

E. Safety valves.

1. Each steam boiler must have one or more officially rated (ASME Code stamped and National Board rated) safety valves of the spring pop type adjusted to discharge at a pressure not to exceed 15 psig. Seals shall be attached in a manner to prevent the valve from being taken apart without breaking the seal. The safety valves shall be arranged so that they cannot be reset to relieve at a higher pressure than the maximum allowable working pressure of the boiler. A body drain connection below seat level shall be provided by the manufacturer, and this drain shall not be plugged during or after field installation. For valves exceeding two inch pipe size, the drain hole or holes shall be tapped not less than 3/8 inch pipe size. For valves less than two inches, the drain hole shall not be less than ¼ 1/4 inch in diameter.

2. No safety valve for a steam boiler shall be smaller than 3/4 inch unless the boiler and radiating surfaces consist of a self-contained unit. No safety valve shall be larger than 4-1/2 inches. The inlet opening shall have an inside diameter equal to, or greater than, the seat diameter.

3. The minimum relieving capacity of the valve or valves shall be governed by the capacity marking on the boiler.

4. The minimum valve capacity in pounds per hour shall be the greater of that determined by dividing the maximum BTU output at the boiler nozzle obtained by the firing of any fuel for which the unit is installed by 1,000; or shall be determined on the basis of the pounds of steam generated per hour per square foot of boiler heating surface as given in Table 2. When operating conditions require it a greater relieving capacity shall be provided. In every case, the requirements of subdivision 5 of this subsection shall be met.

TABLE 2 Minimum Pounds of Steam Per Hour Per Square Foot of Heating Surface
	Fire Tube Boilers	Water Tube Boilers
Boiler Heating Surface:
Hand fired	5	6
Stoker fired	7	8
Oil, gas, or pulverized fuel fired	8	10
Waterwall Heating Surface:
Hand fired	8	8
Stoker fired	10	12
Oil, gas, or pulverized fuel fired	14	16
NOTES: When a boiler is fired only by a gas giving a heat value of not in excess of 200 BTU per cubic foot, the minimum safety valve or safety relief valve relieving capacity may be based on the value given for handfired boilers above in Table 2. The minimum safety valve or safety relief valve relieving capacity for electric boilers shall be 3-1/2 pounds per hour per kilowatt input. For heating surface determination, see the current edition of the ASME Code, Section IV.

5. The safety valve capacity for each steam boiler shall be such that with the fuel burning equipment operating at maximum capacity, the pressure cannot rise more than five psig above the maximum allowable working pressure.

6. When operating conditions are changed, or additional boiler surface is installed, the valve capacity shall be increased, if necessary, to meet the new conditions and be in accordance with subdivisions 4 and 5 of this subsection. When additional valves are required, they may be installed on the outlet piping provided there is no intervening valve.

7. If there is any doubt as to the capacity of the safety valve, an accumulation test shall be run (see the current edition of the ASME Code, Section VI, Care of Heating Boilers) VI).

8. No valve of any description shall be placed between the safety valve and the boiler, nor on the discharge pipe between the safety valve and the atmosphere. The discharge pipe shall be at least full size and be fitted with an open drain to prevent water lodging in the upper part of the safety valve or in the discharge pipe. When an elbow is placed on the safety valve discharge pipe, it shall be located close to the safety valve outlet, or the discharge pipe shall be securely anchored and supported. All safety valve discharges shall be so located or piped as not to endanger persons working in the area.

F. Safety relief valve requirements for hot water boilers.

1. Each hot water boiler shall have one or more officially rated (ASME Code stamped and National Board rated) safety relief valves set to relieve at or below the maximum allowable working pressure of the boiler. Safety relief valves officially rated as to capacity shall have pop action when tested by steam. When more than one safety relief valve is used on hot water boilers, the additional valve or valves shall be officially rated and shall be set within a range not to exceed six psig above the maximum allowable working pressure of the boiler up to and including 60 psig and 5.0% for those having a maximum allowable working pressure exceeding 60 psig. Safety relief valves shall be spring loaded. Safety relief valves shall be so arranged that they cannot be reset at a higher pressure than the maximum permitted by this paragraph.

2. No materials liable to fail due to deterioration or vulcanization when subject to saturated steam temperature corresponding to capacity test pressure shall be used for any part.

3. No safety relief valve shall be smaller than 3/4 inch nor larger than 4-1/2 inches standard pipe size, except that boilers having a heat input not greater than 15,000 BTU per hour may be equipped with a safety relief valve of 1/2 inch standard pipe size. The inlet opening shall have an inside diameter approximately equal to, or greater than, the seat diameter. In no case shall the minimum opening through any part of the valve be less than 1/2 inch diameter or its equivalent area.

4. The required steam relieving capacity, in pounds per hour, of the pressure relieving device or devices on a boiler shall be the greater of that determined by dividing the maximum output in BTU at the boiler outlet obtained by the firing of any fuel for which the unit is installed by 1,000, or on the basis of pounds of steam generated per hour per square foot of boiler heating surface as given in Table 2. When necessary a greater relieving capacity of valves shall be provided. In every case, the requirements of subsection subdivision F 6 of this section shall be met.

5. When operating conditions are changed, or additional boiler heating surface is installed, the valve capacity shall be increased, if necessary, to meet the new conditions and shall be in accordance with subdivision F 6 of this section. The additional valves required, on account of changed conditions, may be installed on the outlet piping provided there is no intervening valve.

6. Safety relief valve capacity for each boiler shall be so that, with the fuel burning equipment installed and operated at maximum capacity the pressure cannot rise more than 6 six psig above the maximum allowable working pressure for pressure up to and including 60 psig and 5.0% of maximum allowable working pressures over 60 psig.

7. If there is any doubt as to the capacity of the safety relief valve, an accumulation test shall be run (see the current edition of the ASME Code, Section VI, Care of Heating Boilers) VI).

8. No valve of any description shall be placed between the safety relief valve and the boiler, nor on the discharge pipe between the safety relief valve and the atmosphere. The discharge pipe shall be at least full size and fitted with an open drain to prevent water lodging in the upper part of the safety relief valve or in the discharge pipe. When an elbow is placed on the safety relief valve discharge pipe, it shall be located close to the safety relief valve outlet or the discharge pipe shall be securely anchored and supported. All safety relief valve discharges shall be so located or piped as not to endanger persons working in the area.

G. Valve replacement and repair. Safety valves and safety relief valves requiring repair shall be replaced with a new valve or repaired by the original manufacturer, its authorized representative, or the holder of a "VR" Stamp.

H. Pressure relieving devices. Boilers and fired storage water heaters except those exempted by the Act shall be equipped with pressure relieving devices in accordance with the requirements of Section IV the current edition of the of the ASME Boiler and Pressure Vessel Code, Section IV.

I. Instruments, fittings and control requirements. Instruments, fittings and controls for each boiler installation shall comply with the requirements of the current edition of the ASME Heating Boiler Code, Section IV.

J. Low water fuel cutoff.

1. Each automatically fired hot water heating boiler with heat input greater than 400,000 BTU's BTUs per hour shall have an automatic low water fuel cutoff which that has been designed for hot water service, located so as to stop the fuel supply automatically when the surface of the water falls to the level established in subdivision 2 of this subsection (also see ASME Heating Boiler Code, Section IV).

2. As there is no normal waterline to be maintained in a hot water heating boiler, any location of the low water fuel cutoff above the lowest safe permissible water level established by the boiler manufacturer is satisfactory.

3. A coil type boiler or a water tube boiler with heat input greater than 400,000 BTU's BTUs per hour requiring forced circulation, to prevent overheating of the coils or tubes, shall have a flow sensing device installed in the outlet piping, instead of the low water fuel cutoff required in subdivision 1 of this subsection to stop the fuel supply automatically when the circulating flow is interrupted.

K. Steam gauges.

1. Each steam boiler shall have a steam gauge connected to its steam space, its water column, or its steam connection, by means of a siphon or equivalent device exterior to the boiler. The siphon shall be of sufficient capacity to keep the gauge tube filled with water and arranged so that the gauge cannot be shut off from the boiler except by a cock.

2. The range of the scale on the dial of a steam boiler pressure gauge shall be not less than 30 psig nor more than 60 psig. The gauge shall be provided with effective stops for the indicating pointer at the zero point and at the maximum pressure point. The travel of the pointer from 0 zero to full scale 30 psig shall be at least three inches.

L. Pressure or altitude gauges.

1. Each hot water boiler shall have a pressure or altitude gauge connected to it or to its flow connection in a manner so that it cannot be shut off from the boiler except by a cock with tee or lever handle placed on the pipe near the gauge. The handle of the cock shall be parallel to the pipe in which it is located when the cock is open.

2. The range of the scale on the dial of the pressure or altitude gauge shall be not less than 1-1/2 times nor more than three times the maximum allowable working pressure. The gauge shall be provided with effective stops for the indicating pointer at the 0 zero point and at the maximum pressure point.

3. Piping or tubing for pressure or altitude gauge connections shall be of nonferrous metal when smaller than one inch pipe size.

M. Thermometers. Each hot water boiler shall have a thermometer located and connected so that it shall be easily readable when observing the water pressure or altitude gauge. The thermometer shall be located so that it will at all times indicate the temperature in degrees Fahrenheit of the water in the boiler at or near the outlet.

N. Water gauge glasses.

1. Each steam boiler shall have one or more water gauge glasses attached to the water column or boiler by means of valved fittings. The lower fitting shall be provided with a drain valve of the straightaway type with opening not less than 1/4 inch diameter to facilitate cleaning. Gauge glass replacement shall be possible while the boiler is under pressure.

2. Transparent material, other than glass, may be used for the water gauge provided that the material has proved suitable for the pressure, temperature and corrosive conditions encountered in service.

O. Stop valves and check valves.

1. If a boiler can be closed off from the heating system by closing a steam stop valve, there shall be a check valve in the condensate return line between the boiler and the system.

2. If any part of a heating system can be closed off from the remainder of the system by closing a steam stop valve, there shall be a check valve in the condensate return pipe from that part of the system.

P. Feedwater connections.

1. Feedwater, make-up water, or water treatment shall be introduced into a boiler through the return piping system or through an independent feedwater connection which that does not discharge against parts of the boiler exposed to direct radiant heat from the fire. Feedwater, make-up water, or water treatment shall not be introduced through openings or connections provided for inspection or cleaning, safety valve, safety relief valve, surface blowoff, water column, water gauge glass, pressure gauge or temperature gauge.

2. Feedwater piping shall be provided with a check valve near the boiler and a stop valve or cock between the check valve and the boiler or return pipe system.

Q. Return pump. Each boiler equipped with a condensate return pump, where practicable, shall be provided with a water level control arranged to maintain the water level in the boiler automatically within the range of the gauge glass.

R. Repairs and renewals of boiler fittings and appliances. Whenever repairs are made to fittings or appliances, or it becomes necessary to replace them, the repairs or replacements shall comply with the requirements for new installations.

S. Conditions not covered by this chapter. Any case not specifically covered by this chapter shall be treated as a new boiler or pressure vessel installation pursuant to 16VAC25-50-280 or may be referred to the chief inspector for instructions concerning the requirements.

16VAC25-50-380. Pressure vessels.

A. Maximum allowable working pressure for standard pressure vessels. The maximum allowable working pressure for standard pressure vessels shall be determined in accordance with the applicable provisions of the edition of the ASME Code or API-ASME code under which they were constructed and stamped. The maximum allowable working pressure shall not be increased to a greater pressure than shown on the manufacturers nameplate stamping and data report.

B. Maximum allowable working pressure for nonstandard pressure vessels.

1. For internal pressure. The maximum allowable working pressure on the shell of a nonstandard pressure vessel shall be determined by the strength of the weakest course computed from the thickness of the plate, the tensile strength of the plate, the efficiency of the longitudinal joint, the inside diameter of the weakest course and the factor set by this chapter.

	TStE	=	maximum allowable working pressure, psi
	RFS

where:

TS = ultimate tensile strength of shell plate, psi. When the tensile strength of the steel plate is not known, it shall be taken as 55,000 psi for temperatures not exceeding 700°F.

t = minimum thickness of shell plate of weakest course, inches,

E = efficiency of longitudinal joint depending upon construction. Use the following values:

For riveted joints -- calculated riveted efficiency;

For fusion-welded joints:

Single lap weld	40%
Double lap weld	50%
Single butt weld	60%
Double butt weld	70%
Forge weld	70%
Brazed steel	80%

R = inside radius of weakest course of shell, inches, provided the thickness does not exceed 10% of the radius. If the thickness is over 10% of the radius, the outer radius shall be used.

FS = factor of safety allowed by this chapter.

2. For external pressure. The maximum allowable working pressure for cylindrical nonstandard pressure vessels subjected to external or collapsing pressure shall be determined by the rules in the ASME Code, Section VIII, Division 1, of the ASME Code.

3. Factors of safety. The minimum factor of safety shall in no case be less than 3.5 for vessels built on or after January 1, 1999. For vessels built prior to January 1, 1999, the minimum factor of safety shall in no case be less than 4.0. The factor of safety may be increased when deemed necessary by the inspector to insure the operation of the vessel within safe limits. The condition of the vessel and the particular service of which it is subject will be the determining factors.

4. The maximum allowable working pressure permitted for formed heads under pressure shall be determined by using the appropriate formulas from the ASME Code, Section VIII, Division 1, ASME Code and the tensile strength and factors of safety given in subdivisions 1 and 3 of this subsection.

C. Inspection of inaccessible parts. Where in the opinion of the inspector, as the result of conditions disclosed at the time of inspection, it is advisable to remove the interior or exterior lining, covering, or brickwork to expose certain parts of the vessel not normally visible, the owner or user shall remove the materials to permit proper inspection and to establish construction details. Metal thickness shall be determined utilizing appropriate equipment including drilling if necessary.

D. Pressure relief devices. Pressure relief devices for each pressure vessel installation, not exempt by the Act, shall comply with the requirements of the ASME Pressure Vessel Code, Section VIII.

E. Safety appliances.

1. Each pressure vessel shall be protected by safety and relief valves and indicating and controlling devices which will insure its safe operation. These valves and devices shall be constructed, located and installed so that they cannot readily be rendered inoperative. The relieving capacity of the safety valves shall prevent a rise of pressure in the vessel of more than 10% above the maximum allowable working pressure, taking into account the effect of static head. Safety valve discharges shall be located or piped so as not to endanger persons working in the area.

2. Safety valves and safety relief valves requiring repair shall be replaced with a new valve or repairs shall be performed by the original manufacturer, its authorized representative, or the holder of a "VR" stamp.

F. Repairs and renewals of fittings and appliances. Whenever repairs are made to fittings or appliances, or it becomes necessary to replace them, the repairs or replacements shall comply with requirements for new installations.

G. Conditions not covered by this chapter. All cases not specifically covered by this chapter shall be treated as new installations or may be referred to the chief inspector for instructions concerning the requirements.

16VAC25-50-430. Hydrostatic pressure tests.

A. A hydrostatic pressure test, when applied to boilers or pressure vessels, shall not exceed 1.25 times the maximum allowable working pressure, except as provided by the current edition of the ASME Code. The pressure shall be under proper control so that in no case shall the required test pressure be exceeded by more than 2.0%.

B. See 16VAC25-50-360 A 4 for temperature limitations on particular power boiler installations.

C. When a hydrostatic test is to be applied to existing installations, the pressure shall be as follows:

1. For all cases involving the question of tightness, the pressure shall be equal to the working pressure.

2. For all cases involving the question of safety, the test pressure shall not exceed 1.25 times the maximum allowable working pressure for temperature. During such test the safety valve or valves shall be removed or each valve disk shall be held to its seat by means of a testing clamp and not by screwing down the compression screw upon the spring.

16VAC25-50-460. Blowoff equipment.

A. The blowdown from a boiler or boilers that enters a sewer system or blowdown which is considered a hazard to life or property shall pass through blowoff equipment that will reduce pressure and temperature as required below.

B. The temperature of the water leaving the blowoff equipment shall not exceed 140°F.

C. The pressure of the blowdown leaving any type of blowoff equipment shall not exceed 5.0 five psig.

D. The blowoff piping and fittings between the boiler and the blowoff tank shall comply with Section I of the current edition of the ASME code Code, Section I and ANSI ASME B31.1.

E. All materials used in the fabrication of boiler blowoff equipment shall comply with Section II of the current edition of the ASME code Code, Section II.

F. All blowoff equipment shall be fitted with openings to facilitate cleaning and inspection.

G. Blowoff equipment which conforms to the provisions set forth in the National Board publication, "Boiler Blowoff Equipment", shall meet the requirements of this section.

16VAC25-50-540. Jacketed kettles and miniatures boilers.

Jacketed kettles and miniature boilers are acceptable for installation if constructed and stamped in accordance with Section I, IV, or VIII, Division 1, of the current edition of the ASME code Code and registered with the National Board.

FORMS (16VAC25-50)

R 1 Form, Report of Welded __ Repair or __ Alteration, CVR1 Rev 1.0.

Form R-1, Report of Repair, National Board Inspection Code, NB-66 (rev. 2012).

Form R-2, Report of Alteration, National Board Inspection Code (eff. 1/1/99).

Form R-3, Report of Parts Fabricated By Welding, National Board Inspection Code (eff. 1/1/99).

Form R-4, Report Supplementary Sheet, National Board Inspection Code (eff. 1/1/99).

Form R-1, Report of Repair, NB-66, Rev. 13 (rev. 6/25/2015)

Form R-2, Report of Alteration, NB-229, Rev. 7 (rev.11/12/2015)

Form R-3, Report of Parts Fabricated by Welding, NB-230, Rev. 3 (rev. 9/24/2015)

Form R-4, Report Supplement Sheet, NB-231, Rev. 2, (rev. 9/23/2015)

BPV-5, Boiler or Pressure Vessel Data Report- First Internal Inspection (eff. 1/1/99).

BPV-6, Boiler - Fired Pressure Vessel - Report of Inspection (eff. 1/1/99).

DOCUMENTS INCORPORATED BY REFERENCE (16VAC25-50)

2007 Boiler and Pressure Vessel Code, ASME Code, American Society of Mechanical Engineers.

National Board Bylaws, National Board of Boiler and Pressure Vessel Inspectors, August 8, 1996.

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