255.145 Valves.

(a)Except for cast iron and plastic valves, each valve must meet the minimum requirements, or the equivalent, of ANSI/API 6D (as described in section 10.3 of this Title). A valve may not be used under operating conditions that exceed the applicable pressure-temperature ratings contained in those standards.#

(b)Each cast iron and plastic valve must comply with the following:#

(1)The valve must have a maximum service pressure rating for temperatures that equal or exceed the maximum service temperature.#

(2)The valve must be tested as part of the manufacturing, as follows:#

(i)With the valve in the fully open position, the shell must be tested with no leakage to a pressure at least 1.5 times the maximum service rating.#

(ii)After the shell test, the seat must be tested to a pressure not less than 1.5 times the maximum service pressure rating. Except for swing check valves, test pressure during the seat test must be applied successively on each side of the closed valve with the opposite side open. No visible leakage is permitted.#

(iii)After the last pressure test is completed, the valve must be operated through its full travel to demonstrate freedom from interference.#

(c)Each valve must be able to meet the anticipated operating conditions.#

(d)No valve having shell (body, bonnet, cover, and/or end flange) components made of ductile iron may be used at pressures exceeding 80 percent of the pressure ratings for comparable steel valves at their listed temperature. However, a valve having shell components made of ductile iron may be used at pressures up to 80 percent of the pressure ratings for comparable steel valves at their listed temperature, if:#

(1)the temperature-adjusted service pressure does not exceed 1,000 psig (6.9 MPa); and#

(2)welding is not used on any ductile iron component in the fabrication of the valve shells or their assembly.#

(e)No valve having shell (body, bonnet, cover, and/or end flange) components made of cast iron, malleable iron, or ductile iron may be used in the gas pipe components of compressor stations.#

(f)Except for excess flow valves, plastic valves installed after January 22, 2019 must meet the minimum requirements of a listed specification. A valve may not be used under operating conditions that exceed the applicable pressure and temperature ratings contained in the listed specification.#