Lamontite / ABCO Fitting Instructions

How to fit a Lamontite / ABCO® Large Size Compression fitting


Select the correct size of tube and fitting for the job. Ensure that both are clean, in good condition and free from damage and imperfections.

Copper tube should conform to BS EN 1057 and be of hard (R290) or half-hard (R250) tempers.



  1. Cut the tube square using a rotary tube cutter wherever possible. If a hacksaw is used to cut the tube, a fine toothed blade should be used.

  1. Remove any burr from the inside and outside of the tube ends using a fine toothed file.



  1. Place the flange and compression ring on to the tube.

  1. Insert the tube firmly into the fitting body, ensuring that the compression ring seats centrally and that the tube makes firm contact with the tube stop in the body.

  1. Bring up the compression flange, and tighten the nuts by hand. Using a spanner continue to tighten the nuts diagonally in increments on ½ turn, to a minimum of 2 turns and maximum of 2 ½ turns. DO NOT OVER TIGHTEN THE NUTS.

  1. The compression flange should be parallel to the face of the body to indicate that a sound joint has been made.

  1. If after assembling the joint in accordance with the instructions above a slight weep is experienced – as occasionally may happen – it will readily be corrected by the application of a smear of an approved sealing compound to the sealing faces.

n.b. before fitting any reducer, remove the flange and compression ring from the end to which the reducer is being fitted. The instructions at point 3 for tightening the nuts should also be followed for fitting a reducer.


PLEASE NOTE: Lamontite / ABCO LS905IM-3 & LS905IM-4 Imperial Compression Rings are only compatible with ABCO LS130IM, LS131IM, LS134IM and LS138IM fittings. They should not be used with any other fittings.