California Code of Regulations › Title 8 - Industrial Relations › Division 1 - Department of Industrial Relations › Chapter 4 - Division of Industrial Safety › Subchapter 15 - Petroleum Safety Orders-Refining, Transportation and Handling › Article 18 - Unfired Pressure Vessels, Boilers, and Fired Pressure Vessels and Pressure Relief Valves › Section 6858 - Pressure-Relieving Devices

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
(a)
					 All pressure vessels shall be protected by a pressure relief device. Such
					 relief devices shall be set to prevent the pressure in the vessel from
					 exceeding limits established by the ASME Code or, where permitted, the Unfired
					 Pressure Vessel Safety Orders. Pressure vessels that are connected together in
					 a system with piping not containing valves that can isolate any pressure vessel
					 while connected to its source or pressure may be considered as one
					 unit.
(b) A vessel having a stop
					 valve that can isolate the vessel from its pressure-relieving device, as
					 permitted in subsection (c), shall be protected by an additional safety device,
					 if the vessel may become entirely filled with liquid, and if it is possible
					 that pressure may be generated by continued input of heat through exchanger
					 tubes or similar devices or by exposure to sun or adjacent hot equipment. This
					 additional safety device shall be connected to the vessel at all times except
					 as permitted in subsection (c)(3). The additional safety device may be set at a
					 pressure not greater than one and one-quarter times the maximum allowable
					 working pressure.
(c) Stop Valves
					 Between Pressure-Relieving Device and Vessel.
(1) A vessel in which pressure can be
					 generated because of service conditions shall have no stop valve between the
					 vessel and its pressure-relieving device except for inspection or repair
					 purposes, as permitted in subsection (c)(3), or except in cases where multiple
					 pressure-relieving devices are provided and the stop valves are so constructed
					 that they can not be operated so as to reduce the pressure-relieving capacity
					 below that required.
(2) A vessel
					 in which the pressure originates from an outside source exclusively may have
					 its pressure-relieving device on the vessel or at any point on the system
					 between the vessel and its source of pressure, provided that the
					 pressure-relieving device is set to function at not over the maximum allowable
					 working pressure of the vessel. Under these conditions there may be a stop
					 valve between the vessel and the pressure-relieving device which need not be
					 locked open if the stop valve also closes the vessel from its source of
					 pressure. Any stop valve between the pressure-relieving device and the vessel
					 which does not close the vessel from its source of pressure shall meet the
					 requirements given in subsection (c)(1) above.
(3) Stop valves may be installed between a
					 pressure relief device and the operating vessel for the purposes of inspection,
					 repair and/or replacement of the pressure relief device. Where stop valves are
					 installed, the employer shall develop, implement, and maintain a written plan
					 containing all of the following:
(A)
					 Procedures to ensure that stop valves are open and locked or sealed during
					 normal operations and are not to be closed except by a qualified person(s).
NOTE: In the case of multiple relief device installations
						having spare capacity or spare relief valves, the stop valve can be closed on
						the inactive relief valves providing sufficient system relief capacity is
						maintained.
(B) Procedures
					 to minimize the frequency of closing stop valves while the vessel is in
					 service. Stop valves shall remain open and locked or sealed until a replacement
					 pressure relief device is available for installation.
EXCEPTION: Stop valves may be closed for emergencies such
						as pressure relief device failure.
(C) Procedures to ensure that a replacement
					 pressure relieving device or needed replacement parts are readily available
					 prior to closing the stop valve and removing the pressure relief device. An
					 index for the location of all stop valves subject to this section shall be
					 maintained.
(D) Before the removal
					 of a pressure relief device from operating equipment, facility management shall
					 review and approve a written operations plan for closing the stop valves. The
					 plan shall incorporate, at a minimum, the following elements:
1. An engineering review to ensure that no
					 increase in the capacity, pressure, severity, and/or operating condition of the
					 unit or vessel will affect the safety of employees or equipment while the
					 pressure relief device is out of service;
2. Provisions for written notification and
					 operational procedures to unit controllers, operators and other affected
					 personnel, including the safeguards and estimated time the valve will be out of
					 service;
3. Identification of the
					 functional position(s) or employees having knowledge of the operating equipment
					 and pressure-relieving device(s) authorized to approve closing a stop valve;
					 and,
4. Identification of the
					 qualified person(s) or functional position(s) authorized to actually close and
					 then reopen a stop valve.
(E) A written overpressure relief plan for
					 each safety relief device shall be developed prior to closing the stop valve.
					 The plan shall include:
1. The means by which
					 overpressure-relief protection will be provided during the time that the
					 pressure relief device is out of service;
2. The procedures to be followed to minimize
					 the time that the stop valve will be closed;
3. The operating conditions, limitations, and
					 other safety measures which are required to be observed to protect employees
					 and equipment; and,
4. In the event
					 that the plan requires a standby person to manually operate a vent to the
					 atmosphere, a replacement safety relief valve shall be available for
					 installation prior to closing the valve. Employees shall be protected from
					 hazards as identified by Article 10 of the General Industry Safety
					 Orders.
(F) The written
					 overpressure-relief plan shall be made available to the Division upon request
					 during the course of the work operation to which it
					 applies.
(4) Valves as
					 permitted above shall not be gate valves installed with the stems pointing
					 above the horizontal plane of the valve body or globe valves installed so that
					 the disk will open against pressure. This limitation need not apply to stop
					 valves closing the vessel from its source of pressure. Other provisions
					 acceptable to the Division may be used to assure that the valve is in the open
					 position.