Once the pipes have been cut square, make sure all components are clean.. Most people use a piece of steel wool to do this.
Assembling the joint
Place the first nut over one of the sections of pipe.
Next, place the olive over the pipe and push it along a little. Some olives have a right and wrong way round. If this is the case, they will have a different size chamfer on each side. The longest one goes against the middle of the joint.
Place the fitting over the pipe and push it home. Line up the nut and hand-tighten.
Tightening the pipe joint
Using two spanners, hold the body of the fitting still with one, whilst tightening the nut with the other. It is important to tighten this nut by the right amount. If it is not fully tightened, the joint will not be watertight. If, however, the nut is overtightened, the olive and pipe can become distorted and the connection will leak. As a guide, the nut will usually require one complete revolution in addition to the hand-tightening. As the spanner is turned, you will feel some obvious resistance as the olive is pushed against the pipe. At this point, it will only need a little additional tightening to become watertight.
It’s one of those skills which comes with practice. To play safe, avoid overtightening. If the joint leaks, it can then be tightened a little until the leak stops. However, if overtightened, a leaking joint will need to be dismantled and repaired.
Some people wrap a little PTFE tape around the thread, or use jointing compound. However, neither should be required for a watertight connection.
Note that all pipework should be adequately supported using pipe clips.
