William Johnston & Company Limited are the leading manufacturer of drinking water gaskets for the water utilities in the UK.
William Johnston & Company Limited have, for almost half a century, been the largest gasket manufacturers supplying the water, waste water and gas utilities and the pipeline industry in the UK. Our particular specialism, on which we have established a very robust reputation, is the supply of WRAS approved, high quality sealing products to the UK water industry and, in particular WRAS approved EPDM gaskets, which we introduced to the UK market in the 1970s.
A gasket is a seal that is designed to prevent leakage of liquid or gas between two mating surfaces. The gasket is usually compressed so that a tight seal is made.
EPDM (Ethylene Propylene Diene Monomer) rubber is a synthetic (man-made) elastomer (rubber) with high technical properties which is capable of making and maintaining a strong, long term seal.
The main properties of EPDM are its outstanding heat, ozone, and weather resistance. It is suitable for use against various temperature and pressure combinations coupled with strong Ozone and UV stability and resistance to degradation.
EPDM is compatible with, hot and cold water, both fresh and saline and alkalis.
It has excellent electrical insulating properties and good resistance to ketones, ordinary diluted acids, and alkalis. Its resistance to polar substances and steam is also good. It is not suitable as a seal against most oils, hydrocarbons, halogenated solvents, and concentrated acids.
WRAS (Water Regulations Advisory Scheme), or WRC (Water Research Council) approved EPDM is a specific grade of EPDM. Introduced into the UK by William Johnston & Company Limited in the 1970s, EPDM gasket material is today the universally approved sealing product for drinking water applications in the UK.
William Johnston and Company Limited offer WRAS approved EPDM that conforms to BS 6920 W70 and BS EN 681-1in sheet, cut gasket and strip formats. Our manufacturing processes and management system are quality assured to ISO 9001:2008 and ensures our standard practice is best practice.
We offer WRAS approved EPDM cut gaskets in a standard 3mm thickness, but other thicknesses are available. We are happy to discuss your application.
We are happy to offer advice and assistance in material selection and on sealing applications. Please contact our technical team.
Calendared |
Moulded |
Extruded |
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We cut gaskets from calendared rolls or sheets. |
Mouled parts are used as valve and pump seals amongst other applications. |
Extrusions can be used as tank, chamber, door and vat lid seals amongst many other applications |
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These gaskets are used as low pressure pipeline seals |
O rings, butterfly valve seals, metal to rubber bondings, man way seals, tank door seals |
Extrusions are used as seals in WTPs, hydro schemes, etc. |
Full Face |
Inner Bolt Circle (Ring) |
Mickey Mouse (2 LUG) |
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USING A STEEL RAISED FACE FLANGE |
USING A STEEL RAISED FACE FLANGE |
USING A STEEL RAISED FACE FLANGE |
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FLAT FACE FLANGES CAN BE USED WITH THE SAME GASKET STYLES BUT PLEASE REMEMBER THAT YOU ARE COMPRESSING A LARGER SURFACE AREA OF MATERIAL THAN WITH TWO RAISED FACE FLANGES. INCREASE IN BOLT TORQUE IS REQUIRED. |
For more information about our EPDM Gaskets that are available world wide, contact us on +44 (0)141 620 1666, Email us or simply complete our online Enquiry Form.