Plan 62 is designed to improve the environment on the atmospheric side of single seals by adding a quench. Typically, this quench is low pressure steam, nitrogen or water to prevent the formation of  solids on the atmospheric side of the seal.  Plan 62 is typically used with a floating or segmented bushing to limit the leakage of the quench fluid to atmosphere, but can be used with a fixed bushing.

Typically, quench flow rates are very low.  For steam, a slight visible “wisp” is recommended.  For water a slight visible drip is recommended.

A problem resulting from a steam or water quench is that the bearings (usually immediately near the gland plate) can become contaminated with the quench fluid.  This is the reason for providing a close clearance bushing and a drain that is piped away from the seals/bearings.