Extend copper pipe using existing compression fitting

TheGreenFrog

I have a water softener which is attached to 22mm copper pipes using high flow hoses with 3/4 fittings.  Each pipe teminates in a compression fitting with male 3/4 to attach the hose.  I need to reposition the softener slightly - but then the hoses will not reach the pipes and sufficiently long replacement hoses are not easily available so I am looking to extend the copper pipes.  Can I use the existing fittings in any way to do this, or do I have to cut it off and use a new coupler?  

grumbler

A photo would help, but yes, you can.

Remove the nut and the olive on one side and use the nut and the olive on your pipe to connect it to the barrel. Then connect the extra piece of pipe to the other side of the coupler. Then connect the existing hose fitting to the other end of the piece.

As simple as that.

TheGreenFrog

Attached is a photo of the exsting pipe fitting

ThisIsWeird

I'd recommend getting a small tin of Fernox Hawk White (suitable for potable water if needed) - a jointing compound - especially for when existing fittings are being reused.

When you dismantle the old, clean it up and give it a smear - over the olive, and also on the male thread. That will both help seal against any leaks, but will also lubricate the fitting and make doing it up a much nicer experience.

(Also use it on the new ends. Just a smear.)

TheGreenFrog

ThisIsWeird said:

I'd recommend getting a small tin of Fernox Hawk White (or similar) - a jointing compound - especially for when existing fittings are being reused.

When you dismantle the old, clean it up and give it a smear - over the olive, and also on the male thread. That will both help seal against any leaks, but will also lubricate the fitting and make doing it up a much nicer experience.

(Also use it on the new ends. Just a smear.)

Was hoping to avoid dismantling the existing compression fitting - if that is unavoidable then I may just cut the pipe and use a new fitting as not confident of my skills where old fittings concerned!

grumbler

Just remove the remaining part and replace it with the coupler like I suggested.

Then use the nut an the olive to fix this part to the other end of the extra piece of pipe.

Keep_pedalling

ThisIsWeird said:

I'd recommend getting a small tin of Fernox Hawk White (or similar) - a jointing compound - especially for when existing fittings are being reused.

When you dismantle the old, clean it up and give it a smear - over the olive, and also on the male thread. That will both help seal against any leaks, but will also lubricate the fitting and make doing it up a much nicer experience.

(Also use it on the new ends. Just a smear.)

That should not be used on plumbing associated with drinking water.

TheGreenFrog

grumbler said:

Just remove the remaining part and replace it with the coupler like I suggested.

Then use the nut an the olive to fix this part to the other end of the extra piece of pipe.

Does't that involve uncompressing the existing join to the pipe and then reusing the olive attached to the pipe?  The join is in a place where a leak would cause a lot of problems and am worried about joining onto old olives.

grumbler

TheGreenFrog said:

grumbler said:

Just remove the remaining part and replace it with the coupler like I suggested.

Then use the nut an the olive to fix this part to the other end of the extra piece of pipe.

Does't that involve uncompressing the existing join to the pipe and then reusing the olive attached to the pipe?  

Not sure about 'uncompressing' - the compressed olive remains on the original pipe.

The join is in a place where a leak would cause a lot of problems and am worried about joining onto old olives.

These fittings aren't single-use. The olive is made from soft metal. If there is a leak just tighten the nut. In the worst case scenario disassemble it and 'dress' the olive with few layers of PTFE tape before assembling back. I've done this dozens of tims.

nofoollikeold

1. I agree with the process grumbler has suggested.
2. If you are worried about re-using the original olives:
2.1 Undo the compression nuts (furthest from open end of pipe in picture) carefully, holding the narrower hexagon with one spanner while undoing the nut with another to prevent the fitting from spinning on the pipe. 
2.2 Clean any old sealant off the end of the pipe and the olive.
2.3 Wrap 5 or 6 turns of ordinary PTFE tape around the olive.  Wind it on ant-clockwise looking at the open end of the pipe.
2.4 Alternatively apply a sealant (not Hawk white, something like Jetlube V2) around the olive.
3. If you are really worried, remove the old olives and buy and fit some new 22mm copper olives.  The old olive can be removed in a number of ways.  Probably the most reliable without an olive puller is to open an adjustable spanner to a fraction wider than the pipe diameter, put the jaws behind the compression nut, and tap the spanner forward towards the open end of the pipe.  
4. And if none of the above suits, get a pipe slice and cut the pipe behind the compression nut.  Clean the cut end up for about 40 mm with wire wool, or a green pipe cleaning strip.  I wouldn't use sandpaper or an abrasive carbide strip for a compression fitting.  

TheGreenFrog

All clear.  Thank you