API 62 PLAN

The purpose of a Plan 62 external quench is usually to stop the build up of something on the atmospheric side of the seal. Steam quenches are often used to keep air (oxygen) away from the seal faces to prevent coking etc.

If this is your case then there is no pressure required as the drain is to atmosphere, so you only need to supply sufficient steam to exclude air ingress.

There is a danger if you have the steam pressure too high. It is posssible that you may dislodge the seal seat causing a seal failure. So the steam pressure should be kept low (ideally1 psi or less). The steam should be of good quality or a steam trap should be recommended as there is a danger of wet steam flashing at the seal and causing damage. The purpose usually of the steam quench is to exclude the oxygen in the air from round the atmospheric side of the seal (usually on hot hydrocarbon duties) and so preventing the formation of coke. Nitrogen is also sometimes used.

Dear friend

API plan 62 stated the quench fluid coul be steam, nitrogen or water.

Quench pressure should be limited to 0.2 bar or less, and feed pipe diameter for quench inlet could have same diameter as port of mechanical seal gland.

Hope this help