Control Valve Seat Leakage Classification

In many process applications, there is a fundamental requirement that a control valve should be able to completely stop fluid flow when in fully closed position. In practice, this is often not the case as many control valves still allow fluid passage even when in fully closed position. To overcome this problem, control valve installations usually have a block upstream and another downstream to provide tight shut off of fluid if desired.

We have several classifications for control valves, rating them in their ability to

fully shut off process fluid. The ANSI classification of control valve according to seat leakage tolerances is shown in the table below:

Read more »