Kaxite phenolic insulating washers are dielectric washers fitted on the flange studs between the flange and the flat steel washers, breaking the electrical path between the fastener and the flange face. Manufactured from fabric-reinforced laminated phenolic — also available in a non-asbestos laminate — they deliver good mechanical strength and dimensional stability, excellent dielectric strength, and low moisture absorption. They work with all standard sleeve materials including Mylar, Minlon, polyethylene and phenolic. Standard thickness is 1/8" (3.175 mm); standard metric and imperial bolt sizes are stocked for immediate supply, and custom ID / OD / thickness combinations are produced to order. Washers are supplied as individual components or as part of a complete flange insulation kit with matched gaskets and sleeves. Standard sizes ship in 5–10 days, custom sizes in 10–20 days. OEM / wholesale pricing applies from first order for standard sizes and from 500 pieces per size for custom cut.
Phenolic insulating washers fit on the studs between the flange and the flat steel washers, breaking the electrical path between the fastener and the flange face. Together with an insulating gasket at the joint face and insulating sleeves through the bolt holes, they complete the three-component isolation system used on every mixed-metal or cathodically protected flanged joint.
Manufactured from fabric-reinforced laminated phenolic (also available in non-asbestos sheet), these washers deliver good mechanical strength and dimensional stability, excellent dielectric strength, and low moisture absorption. They work with any standard sleeve material — polyethylene, Mylar, Minlon or phenolic — and are stocked in standard metric and imperial bolt sizes for immediate supply.
Phenolic insulating washers are dielectric washers fitted onto the flange studs between the nut (or bolt head) and the flat steel washer. Their job is to isolate the fastener from the flange metal so no current can flow between the two sides of the joint — the third of the three dielectric components that together isolate a flanged joint.
The base material is fabric-reinforced laminated phenolic — a composite made from woven fabric impregnated with phenolic resin and cured under heat and pressure into a dense, dimensionally stable sheet. Unlike a moulded plastic washer, the laminate holds its shape and strength under sustained bolt load, so the isolating layer does not creep or extrude when the joint is torqued to specification.
Washers are stocked in standard metric and imperial bolt sizes for immediate supply, and are also supplied as complete kits with matching gasket and sleeves, or cut to non-standard dimensions on request.
Three insulating washer materials are commonly specified in the pipeline industry. Phenolic is the default, cost-efficient choice for most standard joints. G-10 / G-11 glass epoxy is specified where the joint runs hotter or where higher mechanical strength is required. Mylar is generally used for sleeves rather than washers. Compare the three below.
Standard choice for most pipeline joints. Balanced cost and performance.
Higher temperature and higher strength option. See G-10 and G-11 pages.
Generally used for bolt-hole sleeves rather than washers. See Mylar sleeve.
Insulating a flanged joint requires breaking every current path through the connection. In a fully insulated joint that means three dielectric components working together — remove any one and the isolation fails.
At the flange face. Type D, E or F geometry depending on the flange standard.
Through each bolt hole. Typically Mylar, Minlon, polyethylene or phenolic.
On the stud between the flange and the flat steel washer. Breaks the fastener-to-flange path.
Between the phenolic washer and the nut — protects the washer from scuffing under the torque.
Washers are supplied in standard metric and imperial bolt sizes or cut to your specific inside diameter, outside diameter and thickness. Send the following details and Kaxite will return a quotation — typically within one working day for standard sizes.
It is made from fabric-reinforced laminated phenolic — a composite of woven fabric impregnated with phenolic resin, cured under heat and pressure into a dense sheet, then machined to the required ID, OD and thickness. A non-asbestos laminate variant is also available on request.
A fully insulated joint has three dielectric components: the gasket at the flange face, the sleeve through the bolt hole, and the washer on the stud between the flange and the flat steel washer. The phenolic washer is the third of these — it breaks the current path between the fastener and the flange face. Removing or omitting any one of the three will cause the isolation to fail.
Both are dielectric laminates. Phenolic is the standard, cost-efficient choice for most pipeline joints. G-10 and G-11 are woven glass fabric laminates with higher mechanical strength and higher maximum service temperature — see the G-10 and G-11 pages. If the joint runs hot or needs higher strength, specify G-10 or G-11; for standard joints phenolic is usually sufficient.
Yes. Washers are supplied as individual components or as part of a complete flange insulation kit with matched sleeves and gaskets. Available sleeves include Mylar, Minlon, polyethylene and phenolic — see the phenolic sleeve and insulation sleeve pages.
Yes. Standard metric and imperial bolt sizes are stocked for immediate supply — typically 5–10 days depending on quantity. Custom non-standard ID / OD / thickness combinations are produced to order, generally 10–20 days.
The standard thickness is 1/8" (3.175 mm). Custom thicknesses are available on request — send the required finished thickness and we will confirm feasibility and lead time.
OEM and wholesale pricing applies from the first order for standard metric and imperial sizes, and from 500 pieces per size for custom-cut washers. Send the annual or project quantity and we will quote the volume tier.
Yes. Phenolic washers are compatible with any standard sleeve material — Mylar, Minlon, polyethylene or phenolic. The sleeve material is chosen separately based on the joint's temperature and mechanical requirements; the washer material is chosen for its dielectric and mechanical properties under the bolt head.
Send the bolt diameter, washer OD, thickness and quantity — or the flange standard and size for a complete kit quotation. Kaxite supplies phenolic washers for OEM flange insulation kits, maintenance replacement, and standalone electrical insulation applications.
