Aluminum Union for Air Pipe by Prevost

Prevost PPS1 UN Aluminum Union for Compressed Air Pipe

The PPS1 UN union is the straight coupling of the Prevost aluminum air pipe system. It joins two lengths of pipe of the same outside diameter with a compression connection on each end: cut the pipe square, chamfer it, push it in to the mark and tighten the nut. No threading, no glue, no welding, and the joint comes apart again if the layout changes. Nine sizes cover 1/2 inch through 4 inch pipe.

Where unions go

One union per pipe to pipe joint. Prevost pipe comes in 9.5 and 18 foot lengths, so a 100 foot main run in 18 foot sticks needs five unions plus whatever is cut short at the ends. Elbows, tees and valves carry their own compression ends, so you do not need a union to join pipe to a fitting, only pipe to pipe. Unions are also the repair fitting: cut out a damaged section, chamfer the new ends and couple the replacement piece in with two unions. They are the normal way to tie a new branch into an existing run as well, together with a tee.

Installation notes

Use the Prevost chamfering tool on every cut; a square, chamfered end is what lets the seal seat without scoring. Mark the insertion depth on the pipe so you can see the pipe is fully home before tightening. Support the pipe with a bracket and clamp near each joint and at the spacing in the Prevost manual, and let the run breathe: aluminum pipe moves with temperature and the compression joints are meant to carry that movement, not fight it. Order unions with your elbows, ball valves and threaded adapters, or send us a sketch through the piping plan request and we will count the fittings for you.

Available Variants and SKUs

All variants and part numbers for this product are listed below for easy reference and ordering.