Control of Pressure of Gas Delivered from High-Pressure Distribution Systems

§ 192.197 Control of Pressure of Gas Delivered from High-Pressure Distribution Systems#

(a)Each operator shall establish a maximum actual operating pressure for each distribution system as required by § 192.622.#

(b)If the maximum actual operating pressure of the distribution system is 60 p.s.i. (414 kPa) gage, or less, and a service regulator having the following characteristics is used, no other pressure limiting device is required:#

(1)A regulator capable of reducing line pressure to pressures required to safely operate the customers' gas utilization equipment.#

(2)A regulator with an internal relief valve vented to the outside atmosphere or an overpressure control device. A single port valve with the orifice size commensurate with the inlet pressure to assure adequate volume and pressure to the customer and also assures the overpressure control device prevents the build-up of pressure that would cause the unsafe operation of the customers' gas utilization equipment.#

(3)A valve seat made of resilient material designed to withstand abrasion of the gas, impurities in gas, cutting of the valve, and to resist permanent deformation when pressed against the valve port.#

(4)Pipe connections to the regulator not exceeding 2 inches (51 millimeters) in diameter.#

(5)A regulator that, under normal operating conditions, will regulate the downstream pressure within the necessary limits of accuracy and prevents the build-up of pressure under no flow conditions that would cause the unsafe operation of the customers' gas utilization equipment.#

(6)A self-contained regulator with no external static or control lines.#

(c)If the maximum actual operating pressure of the distribution system is 60 p.s.i. (414 kPa) gage, or less, and a regulator that does not have all the characteristics listed in paragraph#

(b)of this section is used, or if the gas contains materials that seriously affects the operation of the regulator, there must be suitable protective devices installed to prevent over-pressuring the customers' gas utilization equipment if the regulator fails.#

(d)If the maximum actual operating pressure of the distribution system exceeds 60 p.s.i. (414 kPa) gage, one of the following methods must be used to regulate and limit to a safe value, the pressure delivered to the customers' gas utilization equipment:#

(1)A service regulator having the characteristics listed in paragraph#

(b)this part, and another regulator located upstream from the service regulator. The upstream regulator may not be set to maintain a pressure higher than 60 p.s.i. (414 kPa) gage. If the upstream regulator does not have an internal relief valve of sufficient capacity to limit the pressure to the service regulator to 60 p.s.i.(414 kPa) gage, a device must be installed between the upstream regulator and service regulator to limit the pressure to the service regulator to 60 p.s.i.(414 kPa) gage or less in case the upstream regulator fails to function properly. This device may be either a regulator, relief valve, or an automatic shutoff that shuts if the pressure on the inlet of the service regulator exceeds 60 p.s.i. (414 kPa) gage, and remains closed until manually reset.#

(2)A service regulator and a monitoring regulator set to limit, to a safe value, the pressure delivered to the customer. Both regulators must be constructed to withstand the maximum inlet pressure.#

(3)A service regulator and an automatic shutoff device that closes upon an unsafe rise in pressure downstream from the regulator and remains closed until manually reset.#

(e)If the maximum actual operating pressure does not exceed 125 p.s.i. (862 kPa) gage, a service regulator having the characteristics listed in paragraph#

(b)of this section and a manufacturer's inlet working pressure rating of 125 p.s.i. (862 kPa) gage or higher, may be used. If the internal relief valve capacity will prevent the downstream pressure from exceeding a safe value, or an overpressure control device is installed, no additional pressure limiting device is required.#