The 3 Types of Control Valve Trim

What is Control Valve Trim?

Valve trim consists of three basic items: the stem, ball, and seat. These are the operative parts that control the flow of liquid and gas through a valve. They are also the parts most exposed to process elements, and therefore most vulnerable to wear.

What Types of Valve Trim Are There?

There are three primary types of control valve trim:

  • snap trim (also referred to as quick opening)
  • nominal trim (also referred to as linear)
  • equal percentage trim

Types of Valve Trims

A valve trim’s flow characteristic is the relationship between the percentage of flow and the percentage of valve stem travel between 0% and 100%. 

Snap Valve Trim

Snap Valve Trip opens quickly and is used for on/off service. Primary applications include liquid dump, pressure relief, and metering. We also offer zirconia seats for erosive applications.

Nominal Valve Trim

Nominal valve trim is used for throttling liquids, liquid level control, and in applications where water hammering has been an issue.

Equal Percentage Valve Trim

Equal percentage valve trim is used to control pressure or flow of gases and vapors in throttling applications.

Hopefully this clarifies which type of trim you need. Keep in mind that you can also swap the trim if your conditions change.

If you’d like further assistance identifying which trim set will best fit your flow conditions, contact your local Kimray store or authorized distributor.

Breck Swigart serves as a Product Manager at Kimray, and is responsible for Kimray’s line of pneumatic valves, pneumatic pilots, regulators and temperature controllers. He collaborates with Kimray’s engineering, manufacturing, and quality teams to optimize the performance of our products and make a difference for our customers.