List for Relief Valve Specifications

End type and size (flanged, screwed, and if flanged, raised face or ring type joint). 

Type of fluid being relieved and corrosivity (Manufacturer may supply a steam relief valve if this is not specified). 

Volume of fluid to be handled under relief conditions. 

The term trim applied to gate valves generally refers to material from which the stem, disc faces and seats are made. Certain other parts such as inside screw-wedge bushings, bonnet bushings, yoke-stem nuts and yoke-wheel-clamp nuts may be made of trim material. 

The standard (API 600) also specifies the following materials for trim parts  

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