Quench

Quench is the term used for an arrangement that applies an unpressurised external fluid to a mechanical seal's outboard faces. The quench liquid can assume the following tasks: 

• Absorption/removal of the seal's leakage
• Monitoring of the mechanical seal's leakage rate
• Lubrication/cooling of the stand-by seal
• Exclusion of air: prevents the leakage from reacting with the atmosphere (e. g. crystallisation of the leaking fluid)
• Dry running protection

The quench fluid is sealed via throttling bushes, preliminary gland packings, radial shaft seal rings, lip seals or mechanical seals (also see Shaft seals).
See Fig. 11 Shaft seal