Pump Unions, O' Rings & Gaskets

In this category, you will find all the plumbing unions, O' rings and gaskets we associate with Hot Tub pumps. We have all the sizes of pump unions available along with their specific O' rings, O' rings for pump faceplates, bleed screws and bleed nipples.

Plumbing Terms Explained

In the hot tub industry, we use many plumbing terms that do not apply to any other plumbing trade so it can be a little confusing. When it comes to hot tub pump unions we, for example, refer to them 2-inch but not one part of this union actually measures 2 inches. They are called this as they are used with American 2-inch imperial plumbing pipe, the imperial pipe is measured internally rather than externally even though the pipe would be glued inside a 2-inch union or plumbing fitting. Pump Gasket/O' Rings are the same principle, they are given their name as they are used with that sized union.

The simplest way to work out the correct union for your hot tub pump is to measure the outside thread diameter of the pump inlet or outlet connection. Here is a quick conversion guide to pump unions.

1 inch Pump Union - 50mm Thread OD

1.5 inch Pump Union - 63mm Thread OD

2 inch Pump Union - 78mm Thread OD

2.5 inch Pump Union - 93mm Thread OD