IPE-EP-5-5-2

IPE Engineering Practice IPE-EP-5-5-2

Document number: IPE-EP-5-5-2 · Section: 5 — Piping

CoInafsletcatilo nA Prouinbta E nEgningeeirninege Prriancgtic Pesractices Welding Requirements for Piping 15.4 For local heat treatment of single valves, one thermocouple shall be attached to the inlet or outlet attachment weld for all valves NPS 1 and smaller. For valves greater than NPS 1, one thermocouple shall be attached to both the inlet and outlet attachment welds. 15.5 Post weld heat treatment of welded valves shall be done by the electric resistance method. Disassembled valves shall use the electric resistance or furnace PWHT technique. Alternate methods of PWHT for welded or bolted bonnet valves may be considered, but require prior approval of the Owner’s Engineer. 15.6 PWHT of Carbon Steel (P–1) valves shall meet the following requirements: 1) PWHT temperature shall be per Table 2. 2) Controlled heating rates shall start at 800°F, and shall be 400°F/hr maximum until the specified PWHT temperature is reached. 3) For AES service, the PWHT time at temperature shall be a minimum of 30 minutes. At the completion of the hold time, cool down for both localized PWHT or furnace PWHT shall be the same as that required for AES carbon steel piping in this Practice. 4) For services other than AES, the time at temperature and cool down rates shall be the same as those required for the connecting piping. 15.7 PWHT of alloy valves that are the same P–number material as the connecting piping shall follow the requirements of the piping. 15.8 (*)PWHT of dissimilar materials (valves and connecting piping with different P–numbers) or alloys not listed in section 11.0, shall require prior review and approval of the Owner’s Engineer.

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