Valve Trim

This term "trim" refers to the internal fittings which are housed in a valve body. The trim includes:

a. Valve plug

b. Valve stem and guide bushings

c. Plug seat

A particular valve body and design may be produced with a number of trim options. For example, the valve trim will be different for a valve produced for abrasive service, in comparison to one which is designed to handle non-abrasive fluids.

The trim depends upon the following factors:

a. Pressure drop across the valve

b. Corrosive properties of the fluid

c. Erosive properties of the fluid

Stainless steel is very commonly used as trim material. It is very versatile and can provide a wide variety of services. Stainless steel, while being tough and durable, is resistive to most corrosive fluids. Many manufacturers have developed their own proprietary metallurgy for trim manufacture. Common registered trade names are “Stellite”, “Colmony” and “Monel”.

Sometimes stainless steel is provided with chrome plating, which results in excellent erosion-resistant properties.