Part IV. General Requirements
16VAC25-50-390. Inspection of boilers and pressure vessels.
All boilers and pressure vessels, not exempt by the Act, shall be inspected internally and externally, as provided by this chapter, by a special inspector. The owner or user shall prepare each boiler or pressure vessel for the inspection and for appropriate pressure tests, whenever necessary. To prepare equipment for an internal inspection the following actions shall be taken as applicable:
1. Boilers
a. Cool the boiler, furnace and setting sufficiently to prevent damage to any part;
b. Drain and wash thoroughly internal parts to be inspected and adequately ventilate all interior surfaces;
c. Remove manhole and handhole plates, wash out openings, drains and inspection plugs;
d. Remove a sufficient number of grates of internally fired boilers, as required by the inspector;
e. Remove brickwork, refractory and insulation, as required by the inspector, to determine condition of boiler, headers, tubes, furnace, structural supports, and other parts;
f. Prevent leakage of water, steam or vapors into boiler interiors that would endanger personnel;
g. Before opening the manhole or handhole covers and entering any parts of the steam-generating unit connected to a common header with other boilers, the nonreturn and steam stop valves must be closed, locked out and drain valves or cocks between the two valves opened. The feed and check valves must be closed, locked out and drain valves or cocks located between the two valves opened. After draining the boiler, the blowoff valves shall be closed and locked out. Blowoff lines, where practicable, shall be disconnected between pressure parts and valves. All drains and vent lines shall be opened;
h. Prepare the pressure gauge for testing; and
i. Comply, where applicable, with Virginia law regarding work conducted within confined spaces pursuant to Virginia Occupational Safety and Health (VOSH) regulation 16VAC25-90-1910.146, Permit Required Confined Space for General Industry.
2. Pressure vessels
a. Remove manhole and handhole plates, cleaning and inspection plugs;
b. Clean internal surfaces and adequately ventilate all interior spaces;
c. Isolate the unit to the extent that internal temperature, pressure and environment are not injurious to personnel and are under strict control during complete inspection;
d. Remove linings or coverings, as required by the inspector, to determine true physical condition of the vessel and its components;
e. Make protective and regulating controls readily accessible for inspection;
f. Prepare the pressure gauges for testing; and
g. Comply, where applicable, with Virginia law regarding work conducted within confined spaces pursuant to Virginia Occupational Safety and Health (VOSH) regulation 16VAC25-90-1910.146, Permit Required Confined Space for General Industry.
Statutory Authority
§ 40.1-51.6 of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.1, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993; Virginia Register Volume 11, Issue 20, eff. August 1, 1995; Volume 15, Issue 5, eff. January 1, 1999.
16VAC25-50-400. Boilers and pressure vessels improperly prepared for inspection.
If a boiler or pressure vessel has not been properly prepared for an internal inspection, or if the owner or user fails to comply with the requirements for a hydrostatic test as set forth in this chapter, the inspector may decline to make the inspection or test and the inspection certificate shall be withheld until the owner or user complies with the requirements.
Statutory Authority
§§ 40.1-22 and 40.1-51.5 et seq. of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.2, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993.
16VAC25-50-410. Removal of covering to permit inspection.
If the boiler or pressure vessel is jacketed so that the seams of shells, drums, or domes cannot be seen, sufficient jacketing, setting wall, or other form of casing or housing shall be removed to permit reasonable inspection of the seams and so that the size of the rivets, pitch of the rivets, and other data necessary to determine the safety of the boiler or pressure vessel may be obtained, provided such information cannot be determined by other means.
The inspector shall not remove any insulation or covering and may refuse to enter boiler or equipment rooms where the inspector believes an asbestos exposure exists. To determine if an asbestos exposure may exist, the inspector may request to review the owner or user's asbestos maintenance program, where applicable, under the Virginia Occupational Safety and Health (VOSH) Program, Occupational Exposure to Asbestos, Construction Industry, Appendix G, 16VAC25-175-1926.1101.
Statutory Authority
§§ 40.1-22 and 40.1-51.5 et seq. of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.3, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993.
16VAC25-50-420. Lap-seam crack.
The shell of a pressure vessel, in which a lapseam crack is discovered along a longitudinal riveted joint, shall be shut down immediately. If the equipment is not more than 15 years of age, a complete new course of the original thickness may be installed at the discretion of the inspector and after approval by the chief inspector. Patching is prohibited.
Statutory Authority
§§ 40.1-22 and 40.1-51.5 et seq. of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.4, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993.
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.
Statutory Authority
§ 40.1-51.6 of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.5, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993; Virginia Register Volume 15, Issue 5, eff. January 1, 1999; Volume 29, Issue 5, eff. December 12, 2012; Volume 35, Issue 2, eff. November 1, 2018.
16VAC25-50-440. Automatic low-water fuel cutoff and/or water-feeding device.
A. Each automatically fired and unattended steam or vapor system boiler, except miniature boilers, shall be equipped with at least two automatic low-water fuel cutoffs located so as to cut off the fuel or energy supply automatically when the surface of the water falls to the lowest safe water line. Functioning of the lower of the two controls shall cause safety shutdown and lockout. The manual reset may be incorporated in the lower cutoff control. If a water-feeding device is installed, it shall be constructed so that the water inlet valves cannot feed water into the boiler through the float chamber and located so as to supply requisite feedwater. The lowest safe water line should be not lower than the lowest visible part of the water glass.
B. The fuel cutoff or water feeding device shall be attached directly to a boiler or in the tapped openings available for attaching a water glass directly to a boiler, provided the connections are made to the boiler with nonferrous tees or Y's not less than 1/2-inch pipe size between the boiler and the water glass so that the water glass is attached directly and as close as possible to the boiler; the run of the tee or Y shall take the water glass fittings, and the side outlet or branch of the tee or Y shall take the fuel cutoff or water feeding device. The ends of all nipples shall be reamed to full-size diameter.
C. Fuel cutoffs and water feeding devices embodying a separate chamber shall have a vertical drain pipe and a blowoff valve not less than 3/4-inch pipe size, located at the lowest point in the water equalizing pipe connections so that the chamber and the equalizing pipe can be flushed and the device tested.
D. A forced circulation coil or water tube type boiler, with a heat input greater than 400,000 BTU's per hour shall have a flow sensing device installed to cut off the fuel supply at a minimum water circulation flow rate in the boiler. The boiler manufacturer's specifications for the safe minimum flow rate, setting, and location of the flow sensing device shall be utilized.
Statutory Authority
§ 40.1-51.6 of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.6, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993; Virginia Register Volume 15, Issue 5, eff. January 1, 1999; Volume 19, Issue 19, eff. July 2, 2003.
16VAC25-50-445. Pressure control devices.
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 with a manual reset that will prevent generation of steam pressure in excess of the maximum allowable working pressure and can cause safety shutdown and lockout.
Statutory Authority
§ 40.1-51.6 of the Code of Virginia.
Historical Notes
Derived from Virginia Register Volume 19, Issue 19, eff. July 2, 2003.
16VAC25-50-450. Pressure-reducing valves.
A. Where pressure-reducing valves are used, one or more relief or safety valves shall be provided on the low-pressure side of the reducing valve when the piping or equipment on the low-pressure side does not meet the requirements for the full initial pressure. Proper protection shall be provided to prevent injury or damage caused by the escaping fluid from the discharge of relief or safety valves if vented to the atmosphere. The combined discharge capacity of the relief or safety valves shall be such that the pressure rating of the lower pressure piping or equipment shall not be exceeded in case the reducing valve sticks open.
B. The use of hand-controlled bypasses around reducing valves is permissible. If a bypass is used around the reducing valve, the safety valve required on the low pressure side shall be sufficient capacity to relieve all the fluid that can pass through the bypass without overpressuring the low pressure side.
C. A pressure gauge shall be installed on the low-pressure side of a reducing valve.
Statutory Authority
§§ 40.1-22 and 40.1-51.5 et seq. of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.7, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993.
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 five psig.
D. The blowoff piping and fittings between the boiler and the blowoff tank shall comply with the current edition of the ASME Code, Section I and ASME B31.1.
E. All materials used in the fabrication of boiler blowoff equipment shall comply with the current edition of the ASME 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.
Statutory Authority
§ 40.1-51.6 of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.8, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993; Volume 35, Issue 2, eff. November 1, 2018.
16VAC25-50-470. Location of discharge piping outlets.
The discharge of safety valves, blowoff pipes and other outlets shall be located so as to prevent injury to personnel.
Statutory Authority
§§ 40.1-22 and 40.1-51.5 et seq. of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.9, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993.
16VAC25-50-480. Repairs and alterations.
A. Prior to any repair, the owner or user shall notify a special inspector with the appropriate endorsement for direction or advice, or both, regarding the method and extent of repair.
B. Repairs to boilers and pressure vessels shall be done in accordance with the National Board Inspection Code by holders of an "R" Certificate of Authorization. The completed repairs shall be reviewed by and found acceptable to the inspector or the same inspection agency who authorized the repair.
C. Alterations to boilers and pressure vessels shall be performed by an organization holding an appropriate ASME or "R" Certificate of Authorization and shall be in accordance with the National Board Inspection Code.
D. All repairs and alterations, except seal welds as defined in this subsection, shall be reported on the applicable Report of Welded Repair or Alteration form. The completed form including proper certification shall be forwarded to the chief inspector by the organization performing the repair or alteration.
E. The completed forms for routine repairs, as the term is defined in the National Board Inspection Code, need not be forwarded to the chief inspector.
Statutory Authority
§ 40.1-51.6 of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.10, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993; amended, Virginia Register Volume 11, Issue 20, eff. August 1, 1995; Volume 15, Issue 5, eff. January 1, 1999 and April 1, 1999; Volume 29, Issue 5, eff. December 12, 2012.
16VAC25-50-490. Supports.
Each boiler and pressure vessel shall be supported by masonry or structural supports of sufficient strength and rigidity to safely support the boiler or pressure vessel and its contents. There shall be no excessive vibration in the boiler, pressure vessel, or their connected piping or fittings.
Statutory Authority
§§ 40.1-22 and 40.1-51.5 et seq. of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.11, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993.
16VAC25-50-500. Boiler door latches.
A. A water tube boiler shall have the firing doors of the inward-opening type, unless such doors are provided with substantial and effective latching or fastening devices or otherwise so constructed as to prevent them, when closed, from being blown open by pressure on the furnace side.
B. These latches or fastenings shall be of the positive self-locking type. Friction contacts, latches, or bolts actuated by springs shall not be used. The foregoing requirements for latches or fastenings shall not apply to coal openings of downdraft or similar furnaces.
C. All other doors, except explosion doors, not used in the firing of the boiler, may be provided with bolts or fastenings instead of self-locking latching devices.
D. Explosion doors, if used and if located in the setting walls within seven feet of the firing floor or operating platform, shall be provided with substantial deflectors to divert the blast.
Statutory Authority
§§ 40.1-22 and 40.1-51.5 et seq. of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.12, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993.
16VAC25-50-510. Clearance.
When boilers are replaced or new boilers are installed in either existing or new buildings, a minimum clearance of two feet on all service sides shall be provided. Boilers and pressure vessels having manholes shall have five feet clearance from the manhole opening and any wall, ceiling or piping that will prevent a person from entering the boiler or vessel. All boilers and pressure vessels shall be located so that adequate space will be provided for the proper operation of the boilers and pressure vessels and their appurtenances, for the inspection of all surfaces, tubes, waterwalls, economizers, piping, valves and other equipment, and for their necessary maintenance and repair and replacement of tubes.
Statutory Authority
§§ 40.1-22 and 40.1-51.5 et seq. of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.13, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993.
16VAC25-50-520. Ladders and runways.
When necessary for safety, there shall be a steel runway or platform of standard construction installed across the tops of adjacent boilers or pressure vessels or at some other convenient level for the purpose of affording safe access. All runways shall have at least two means of exit each to be remotely located from the other.
Statutory Authority
§§ 40.1-22 and 40.1-51.5 et seq. of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.14, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993.
16VAC25-50-530. Air and ventilation requirements.
A permanent source of outside air shall be provided for each boiler room to permit satisfactory combustion of the fuel as well as proper ventilation of the boiler room under normal operating conditions.
A. The total requirements of the burners for all fired pressure vessels in the boiler room must be used to determine the louver sizes whether fired by coal, oil or gas; however, the minimum net free louvered area must not be less than one square foot. The following table or formula shall be used to determine the net louvered area in square feet:
Input BTU Per Hour | Required Air | Min. Net Louvered Area |
500,000 | 125 | 1.0 |
1,000,000 | 250 | 1.0 |
2,000,000 | 500 | 1.6 |
3,000,000 | 750 | 2.5 |
4,000,000 | 1,000 | 3.3 |
5,000,000 | 1,250 | 4.1 |
6,000,000 | 1,500 | 5.0 |
7,000,000 | 1,750 | 5.8 |
8,000,000 | 2,000 | 6.6 |
9,000,000 | 2,250 | 7.5 |
10,000,000 | 2,500 | 8.3 |
B. When mechanical ventilation is used instead of subsection A of this section, the supply of combustion and ventilation air to the boiler room and the firing device shall be interlocked with the fan so the firing device will not operate with the fan off. The velocity of the air through the ventilating fan shall not exceed 500 feet per minute and the total air delivered shall be equal to or greater than shown in this section.
Statutory Authority
§§ 40.1-22 and 40.1-51.5 et seq. of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.15, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993.
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 and registered with the National Board.
Statutory Authority
§ 40.1-51.6 of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.8, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993; Volume 35, Issue 2, eff. November 1, 2018.
16VAC25-50-550. Fuel burning apparatus and systems (flame safeguard).
Fuel burning apparatus and systems shall be equipped with regulating and protective controls in accordance with applicable standards of the American Gas Association, Underwriters Laboratories, ANSI/ASME-CSD-1, or National Fire Protection Association (NFPA) No. 85 Series, or equivalent recognized standards.
Statutory Authority
§§ 40.1-22 and 40.1-51.5 et seq. of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.17, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993.
16VAC25-50-560. Inspection of secondhand or used boilers or pressure vessels.
Inspections of secondhand or used boilers or pressure vessels made by the Chief Inspector or a Commonwealth Inspector shall be charged for in accordance with § 40.1-51.15 of the Act.
Statutory Authority
§ 40.1-51.6 of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.18, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993; Virginia Register Volume 11, Issue 20, eff. August 1, 1995.
16VAC25-50-570. Conditions not covered by this chapter.
For any condition not covered by this chapter, the applicable provisions of the National Board Inspection Code or the ASME code shall apply.
Statutory Authority
§§ 40.1-22 and 40.1-51.5 et seq. of the Code of Virginia.
Historical Notes
Derived from VR425-01-75 § 4.19, eff. July 1, 1974; amended, eff. November 1, 1978; July 1, 1991; September 1, 1993.