Are compression fitting standard size with respect to the distance between the olive on the pipe and the compression surface on the fitting body ? For example if you had stuck olives on a pipe, could you be confident a new coupler (of a different make) would physically work in place of the old one ?
Are compression fittings interchangeable ?
- Thread starter diyjunky
- Start date
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That's a no can be variation between manufacturers and especially between older fittings and current.
I am not a plumber, but no, they would not be identical- even within the same brand of fittings because of manufacturing tolerances.
Ideally the olive will slide up the pipe, or down as required.
In the past I have encountered olives that will not move because the compression fittings were tightened so much that it dented the copper pipes. I ended up having to chop the pipes and solder on inline connectors.
Olive pullers are pretty cheap.
But the above will not pull olives off a kinked/dented pipe
Ideally the olive will slide up the pipe, or down as required.
In the past I have encountered olives that will not move because the compression fittings were tightened so much that it dented the copper pipes. I ended up having to chop the pipes and solder on inline connectors.
Olive pullers are pretty cheap.
But the above will not pull olives off a kinked/dented pipe
1. There is no standard for what is really the insertion depth.
2. However, most seem to be about the same (around 20 mm) from the stop in the fitting against which the pipe abuts to the top of the threaded part the compression nut screws onto.
3. If a pipe with an old olive compressed onto it is inserted into a new compression fitting, there are three possibilities:
3.1 The end of the pipe reaches the internal stop just as the olive touches the chamfered opening of the fitting - no problem.
3.2 The olive touches before the pipe reached the stop - no problem.
3.3 The pipe touches the stop before the olive reaches the chamfer. Then:
3.3a Normally, tightening the compression nut will force the olive towards the end of the pipe - so no problem.
3.3b If the olive has been crushed onto the pipe so much that it has waisted the pipe, then the olive won't move. However, in such cases it is unlikely the fitting will seal fully. The remedy is to cut the pipe about 50 mm before the olive, extend the pipe with a coupler and fit a new olive.
4. When using an old pipe with olive in a new fitting I use Jet Lube V2 smeared around the olive to much reduce the chance of a weep. May not be strictly necessary but much cheaper than a call back. Rather the Jet Lube you can use a few wraps (6 or so) around the olive.
2. However, most seem to be about the same (around 20 mm) from the stop in the fitting against which the pipe abuts to the top of the threaded part the compression nut screws onto.
3. If a pipe with an old olive compressed onto it is inserted into a new compression fitting, there are three possibilities:
3.1 The end of the pipe reaches the internal stop just as the olive touches the chamfered opening of the fitting - no problem.
3.2 The olive touches before the pipe reached the stop - no problem.
3.3 The pipe touches the stop before the olive reaches the chamfer. Then:
3.3a Normally, tightening the compression nut will force the olive towards the end of the pipe - so no problem.
3.3b If the olive has been crushed onto the pipe so much that it has waisted the pipe, then the olive won't move. However, in such cases it is unlikely the fitting will seal fully. The remedy is to cut the pipe about 50 mm before the olive, extend the pipe with a coupler and fit a new olive.
4. When using an old pipe with olive in a new fitting I use Jet Lube V2 smeared around the olive to much reduce the chance of a weep. May not be strictly necessary but much cheaper than a call back. Rather the Jet Lube you can use a few wraps (6 or so) around the olive.
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5. While the vast majority of new fittings will use the same thread for the compression nuts, its not completely universal. For example, Honeywell use a much finer thread on their motorised valves than a normal 22 mm compression nut.
Edited to add point 5
Edited to add point 5
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