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. 1 Quench: Two mechanical seals in tandem arrangement