doing compression fittings.....a little help please?

[morrik27]

I've never done compresion fittings before, but have seen it, and had it explained, several times (a while ago)

my questions relate to this thread: //www.diynot.com/forums/viewtopic.php?t=165567

firstly, when puting the isolators in, do i use PTFE tape on the trhreads, one person told me, " you don't use it on those", but another person said " always use it on threaded fittings...... Which is it?

Secondly, what is the stuf you put on the pipe when fitting the olives, i know it needs to be the typefor potable water fittings, but what is it called?

cheers in advance...

 

[gavinda]

no ptfe ever. you want to use something like hawk white or jet blue on the olives. spot on with making sure its for potable. and remember to use 2 pairs of grips when tightening. one to tighten and one to hold against.

 

[cso30]

Hi

Do not put PTFE tape on a compression joint and don't listen to anybody who tells you to.

To make a good compression joint slide the nut and olive over the end of the pipe and spread some jointing compound around the end of the pipe (don't put it in or on the fitting) then push the pipe into the fitting and tighten up the nut and olive.

'Fernox - water hawk' is for potable there are more that I can't remember the names of, don't use 'Boss green' it's quite awkward to work with on smaller joints.

 

[morrik27]

Hi

Do not put PTFE tape on a compression joint and don't listen to anybody who tells you to.

To make a good compression joint slide the nut and olive over the end of the pipe and spread some jointing compound around the end of the pipe (don't put it in or on the fitting) then push the pipe into the fitting and tighten up the nut and olive.

'Fernox - water hawk' is for potable there are more that I can't remember the names of, don't use 'Boss green' it's quite awkward to work with on smaller joints.

Cheers! Very helpful, particularly regarding boss green - I'd probably have got that (I could remember that there was a red and a green 'spmething' and that the green was for potable use, so i'd probably used that! i'll go find the fernox!!!

Incedently, when WOULD you use PTFE, i thought i was for threads (years ago, when i was a small boy, of about 5or 6, a family friend who lived across the road as was a plumber fitted our bathroom. He was using it and i asked what it was he said "it's PTFE tape, when i asked what it was he said " it means put tape freaded end!" - for some reason it stuck in my head....)

 

[Tipper]

PTFE is for use on thread to thread connections, ie when you have a male and female thread to connect direct with no olives. It fills and seals the gaps in the threads to ensure no leaks.

For olive fittings I find it best to assemble and tighten dry whilst building up the pipework and then when I am happy with it all I undo fitting by fitting and add a smear of sealant around the olive and then re-tighten. This assists in ensuring the olive is 'fixed' in place as they can move about while you are adding the sealant resulting in a poor joint.

 

[cso30]

PTFE - POLYTETRAFLUROETHELENE (I think or something like that anyway)

Only use PTFE on threaded joints e.g. iron pipe, copper to irons, radiator tails etc.

 

[morrik27]

Cheers Tipper, i guess i'll need to put PTFE in the thread where the tap hose connects to the pipework then, as this is a thread-to-thread joint, with a rubber washer in the end of the hose?!

Or am confussing the issue?

 

[cowboyplumber]

PTFE = Plumbers Tape Fixes Everything !

 

[cso30]

For the end of the hose you will need a 1/2" x 15mm male copper to iron, don't be tempted to use a 15mm compression socket because it doesn't have a flat face for the washer to sit on.

Don't use PTFE just use the washer.

 

[morrik27]

So i can't connect the tap hose to one end of the isolator?

 

[Tipper]

If it fits OK then yes. But only if the end of the threaded bit is flat and not tapered as the washer that you should use will not seal well if the end is tapered to a sharp edge.

 

[bengasman]

teflon tape is for tapered thread connections like bsp, not for compression joints.
for a a good compression joint with copper olives, first clean the pipe with fine steelwool.
stick the compression joint on and tighten hand tight. then tighten half turn, regrip and turn on third of a turn, not more, not less. test under full pressure and check. in the unlikely case there is any leakage, turn another quarter turn.
job done

 

[Mr Smyth]

Cowboyplumber said....

PTFE = Plumbers Tape Fixes Everything !

Surely a cowboyplumber would use LSX

 

[gavinda]

lazy sods xcuse