API Plan 62


An external fluid stream is brought to atmospheric side of the seal faces using quench and drain connections.


1. The quench fluid acts as barrier in between atmosphere and process fluid.

2. The quench fluid reduces oxidation and coking of product and also cools seal faces.

3. Flushes away undesirable material build up under seal faces.

4. Can be used with water, steam or an inert gas.


1. In caustic or crystallising fluids.

2. In oxidizing fluids or hot hydrocarbons.

3. Can be used to purge steam in hot applications especially for stationary bellows to avoid coking.


1. Ensure availability of continuous supply of low-pressure quench fluid limited to maximum 1 bar.

2. Use of throttle bushing on atmosphere side is mandatory.

3. Use proper bearing isolators to ensure that the quench fluid does not enter the bearings.

API - 62 4th Edition 30 secs