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SS 316 High performance fittings > Pipe fittings > Overview > Koncentrik® Unions

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Overview - Koncentrik® Unions
Koncentrik Unions join pipe or tubing. Metal-to-metal contact between mating taper angles in the union is reinforced by a fully confined Teflon seal to form a leak-proof joint.
The Koncentrik Union is a four-piece assembly consisting of a threaded piece, tailpiece, union nut, and Teflon seal. The Teflon seal is preinstalled in a precision-machined groove in the male cone shaped tailpiece prior to shipment.
The Teflon seal cushions the metal-to-metal contact of the surfaces and prevents them from becoming galled or scratched. The unions can be taken apart and resealed many times with no damage to the union or loss of sealing effectiveness. Koncentrik Unions are available with tube & pipe socket and butt weld, female pipe thread, and male o-ring boss port end
Suggested Applications
Koncentrik Unions have been used extensively in high pressure ground support missile systems, hydraulic control systems for
turbine generators, and in nuclear and conventional power plant applications.
Koncentrik Unions offer all the advantages of flanges without the disadvantages. Like flanges, Koncentrik Unions can hold high
pressures and can be repeatedly disassembled and resealed. But, unlike flanges, Koncentrik Unions are light in weight and
quick to assemble. Only one nut holds the union together while flanges require several bolts and cumbersome rotational
Feature Koncentrik® Unions
Pressures Very high to 10,000 psi
Temperatures PTFE/Teflon: -100° to 450°F
Vibration Resistance Very Good
Materials Available SS 316/SS 316L stainless M405 Monel
Size Available (nominal) 1/8” – 2” #4 - #32
Seal Reliability Very good PTFE seal reinforced by metal-to-metal seal Medium tolerance to surface imperfections Medium tolerance to assembly variation like under-torquing
Thread & Port Preparation Varies. Connects to tubing, pipe & port connections.
Ease of Assembly Medium. Flats from Finger-Tight method utilized.
Ease of Maintenance Very good. High number of breaks & remakes with Teflon snap-ring replacement.
Specification ANSI B31.1.0 Power Piping
Conformance ANSI B16.11 Forged Steel Fittings Socket
(design & thread) Welded & Threaded