Union fitting

A union is similar to a coupling, except it is designed to allow quick and convenient disconnection of pipes for maintenance or fixture replacement. While a coupling would require either solvent welding or being able to rotate all the pipes adjacent as with a threaded coupling, a union provides a simple nut transition, allowing easy release at any time.

In addition to a standard union, there exist dielectric unions which are used to separate dissimilar metals (such as copper and galvanized steel) to avoid the damaging effects of galvanic corrosion. When two dissimilar metals are placed in an acidic solution (most tap water is mildly acidic), they will form a battery and generate a voltage by electrolysis. When the two metals are in contact with each other the current from one metal to the other will cause a movement of ions from one to the other, dissolving one metal and depositing it on the other. A dielectric union breaks the electric current with a plastic liner between two halves of the union, thus limiting galvanic corrosion.

Material: Brass, Copper, Stainless steel, and other metal alloy
Threader: Female
Size:3/8",1/2",3/4",1"

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