John Crane Type 109B Replacement Mechanical Seal

A Wedge Seal Built for Extreme Temperature Corrosive Duty

The wedge itself is what sets the 109B apart from conventional O-ring or elastomer secondary sealing — a PTFE or graphite wedge tolerates temperatures and chemical exposure that would destroy a standard rubber elastomer outright, which is exactly why this seal shows up in refinery, petrochemical, and hydrocarbon processing applications running well above 200°C. Being a balanced design also means it holds up under higher differential pressures without excessive face wear, even at the demanding end of its 500°C temperature range. Its compact working length keeps it within DIN 24960 dimensions, so it fits standard seal chambers despite the specialized wedge construction inside. Full installation steps for wedge-style secondary sealing are covered in our blog.