Compression Fitting Installation Procedure

Assembly procedure for fittings 25 mm to 50 mm


1) Cut pipe square and remove burrs and chamfer the end of the pipe with a file or chamfering tool. Lubricate end of pipe (lubrication of the pipe end is optional and will ease insertion of the pipe – use silicone lubricant).


2) Undo nut to the last thread. Do not remove the nut.


3) Twist the pipe into the fitting through the nut and split ring until it meets the first resistance – pushing against the captive o-ring.
Then push and twist the pipe past the o-ring until it stops at pipe stop inside the fitting – the final stop. Failure to fully insert the fitting will result in leaks.

4) Firmly hand tighten nut. Use a wrench for a further half turn past hand tight for final tightening of sizes 40 mm and above. The full seal is achieved when the pipe passes through the o-ring. Nut tightening is only to achieve pull out resistance – the seal is automatically created when the pipe is pushed past the captive o-ring.


Assembly procedure for large diameter 63 mm to 110 mm


1) Cut the pipe to the desired length using pipe cutters or a hand saw.


2) Draw the nut, bushing and o-ring on to the end of the pipe to a distance of about twice the pipe diameter. Fitting is made easier by lubricating pipe, o-ring and inside of fitting with silicone lubricant.


3) Insert the pipe into the body of the fitting until stopped by the step. Push o-ring and bushing forward until they reach the fitting.

4+8 tighten nut


4) Tighten the nut with a wrench or spanner until o-ring and bushing enter the fitting and reach end position.


5) Unscrew nut from fitting.


6) Open the split ring and mount on pipe with larger end against bushing.


7) Push the split ring up to meet the body of the fitting.


8) Tighten the nut with a wrench (maximum handle length 40-46 cm or Plasson wrench).
Note: Nut should be closed firmly but nut does not need to actually meet the body.

DO NOT OVERTIGHTEN NUT. Damage could occur to seals, pipe and threads.