scope:

This Recommended Practice (RP) provides guidelines for reconditioning heavy wall (API 600 type) carbon steel, ferritic alloy (up to 9% Cr), stainless steel, and nickel alloy gate, globe, and check valves for ASME pressure classes 150, 300, 400, 600, 900, 1500, and 2500. Guidelines contained in this RP apply to flanged and butt weld cast or forged valves. 

It is an expectation of this Recommended Practice that a contractual agreement shall be established between the Owner and the valve reconditioning facility. The reconditioning facility may be OEM owned/operated, or directly associated and approved by the OEM. At the Owner's option, an independent facility may be used. The Owner shall determine that the facility selected for valve reconditioning has a documented and established working Quality Assurance Program. The Quality Assurance Program should include the essential elements described in Section 7 of API RP 591 or follow the principles of an appropriate standard from the ISO 9000 Series. 

This RP does not cover reconditioning or re-manufacturing of used or surplus valves intended for resale. The only intent of this RP is to provide guidelines for refurbishing an end user's (Owner) valves for continued service in the Owner's facility. Valves reconditioned or re-manufactured to this RP may not meet API Standard requirements for new valves. The correct application of a valve reconditioned to this Practice remains the responsibility of the Owner.