Fluid Sealing and Leak Prevention Rubber Washers for Plumbing

Fluid sealing

Washers for plumbing joints, specified by the joint and the medium

A drip under a faucet is rarely a failed washer. It is usually a washer chosen for the wrong joint — too hard to conform to a scratched seat, too soft to hold torque, or a compound that swells in the medium. We mould and die-cut these to your fitting drawing in silicone, EPDM or NBR, for service from −60 °C to +200 °C depending on compound.

Three compounds, three failure modes

Choosing between silicone, EPDM and NBR is not a preference question — each one has a medium it should never see. The table below is the short version we give to buyers who are consolidating a fitting range onto one compound and want to know where that will break.

Sealing force is a compression question

A washer seals because it is squeezed, not because it is soft. Three numbers decide whether it works: the compression ratio at the specified torque, the stiffness of the flange either side of it, and the width of the land the washer sits on. A thin soft washer on a stiff brass tailpiece will seal; the same washer on a plastic-bodied fitting will relax and weep within a season.

Where they actually go

Pipe and valve connections, faucet and shower fittings, water pumps and filtration housings, industrial piping and pressure vessels, and heating or cooling circuit joints. The same geometry is often used across a family of fittings, which is why a single mould or die can cover a whole product range — worth checking before you assume a new tool is needed.

Moulded or die-cut

Die-cutting is the right answer for flat washers in thin sheet, short runs and revises. Compression or injection moulding is the right answer once the section is profiled, the thickness is above a few millimetres, or the volume justifies a tool and you want the edge quality and dimensional consistency that come with it. We quote both and tell you where the crossover sits for your quantity.

Both routes are inspected against ISO 3601 and ASTM D2000 methods, with hardness, tensile and a leakage simulation on the bench rather than a visual check alone. Food-contact and potable-water grades are available on request.

Dongguan Bohao Electronic Technology Co., Ltd. IATF 16949:2016 / ISO 9001:2015 certified. Values shown are typical for the listed compound or platform; the drawing and the approved sample govern production.