John Crane Type 502 Replacement Mechanical Seal

A Confined-Space Solution for Heavy Industrial Duty

Where the Type 502 earns its place is in gland depths too shallow for standard bellows seals — its full convolution design packs the bellows into a shorter axial space while still self-aligning against shaft end play and run-out the way a longer seal would. Being unitized, the whole assembly arrives factory-set and installs as a single piece, which matters on marine, mixer, and agitator equipment where technicians don't always have the luxury of precise field measurement. It's rated for markedly higher pressure than most bellows-style seals in its size range, which is part of why it turns up across chemical processing, oil and refinery, and general industrial rotary equipment beyond just water service. Our equivalent matches its confined-space dimensions and pressure rating precisely. Full fitting steps and shaft chamfer recommendations are covered in our blog.