Sta-Rite O-Ring 3-3/4″ ID, for Bulkhead Assembly, 35505-1425

Sta-Rite part 35505-1425 is the o-ring for the bulkhead assembly, 3-3/4 in. inside diameter with a 3/16 in. cross section.

Getting the size right

An o-ring is defined by two numbers, the inside diameter and the cross section. Match both. A ring that is the right diameter but thinner than the original will not fill the groove, and the joint will weep under pressure even though the ring looks correct.

Where it is used

It is listed for the Sta-Rite System 3 filter family, covering the S7S50 and S8S70 sand filters and the S7M120, S8M150, S7M400 and S8M500 cartridge filters. If the bulkhead is coming apart for any reason, fit the new ring rather than reusing one that has taken a set in the groove.