API RP 553-2012 PDF

Scope: This recommended practice (RP) addresses the special needs of automated valves in refinery services. The knowledge and experience of the industry has been captured to provide proven solutions to well-known problems. This document provides recommended criteria for the selection@ specification@ and application of piston (i.e. double-acting and spring-return) and diaphragm-actuated (spring-return) control valves. Control valve design considerations are outlined such as valve selection@ material selection@ flow characteristic evaluation@ and valve accessories. It also discusses control valve sizing@ fugitive emissions@ and consideration of the effects of flashing@ cavitation@ and noise. Recommendations for emergency block and vent valves@ on/off valves intended for safety instrumented systems@ and special design valves for refinery services@ such as Fluid Catalytic Cracking Unit (FCCU) slide valves and vapor depressurizing systems@ are also included in this recommended practice.

API RP 553-2012 history