how reliable are compression joints?

Jennie · Feb 28, 2013

Hi all,
I'm curious about the reliability of compression fittings.
I recently re-fitted a compression iso valve to my father's outdoor tap. It had been leak free for 25+ years. But this year, when he opened the valve water gushed out under the sink (the brass olive inside had lost its bite, and the copper pipe could be pulled back/forth in the joint.
I re-made the joint. But it got me thinking.
How reliable could the other fittings in his house be? This was a brass olive (I've seen other posts debating copper v brass olives).
I'm a student plumber, and was formerly under the impression that once a compression fitting had been tested, it was pretty much good for ever. How would you advise a homeowner on this?
I'd be interested to hear your thoughts on this.
Jennie

dancinplumba · Feb 28, 2013

the water in the tap has frozen and pushed the fitting off.

Jennie · Feb 28, 2013

Oh yeah, of course. That leads to another question - how to drain the tap and pipework during winter. He had turned the iso valve off. I suppose he ran the tap on the outside, (but don't know for sure). However, he doesn't have a drain valve fitted, so there would still be water in the pipework. No double check valve either. It's an oldish tap, so I suppose it doesn't have an internal check valve either.
Any tips?
Thanks, Jennie

Reg Man · Feb 28, 2013

Turn off the isolation vavle and leave the outside tap turned on.

Jennie · Feb 28, 2013

Thanks. I'll tell him that. It seems so obvious now.

JCplumb · Feb 28, 2013

It's been mentioned on here before, but for future reference:
If you're fitting an o/s tap, do it in such a way to allow ALL the water to drain out when you close the ISO and open the tap. i.e. pipework goes downhill from internal ISO. Makes winter draining fool proof.

Dannypipe · Feb 28, 2013

In fairness I agree with Reg Man, isolate it and then leave the tap open and it will be OK. But what you say is true, there should be a way to drain the tap/pipe work too.

I've got customers who are way too lazy to bother doing that though!

Dannypipe · Feb 28, 2013

I'm considering putting in a tee and a lever valve as a drain off for a customer who I'm going to see on Saturday as I just know they won't use the drain cock if I fit one.

Keefy · Feb 28, 2013

I'm currentlly putting together an 'Outside Tap Maintenance' advice sheet for future customers. I'll print a load off and make sure each customer gets a copy along with their receit.

Dannypipe · Feb 28, 2013

Keefy said:
I'm currentlly putting together an 'Outside Tap Maintenance' advice sheet for future customers. I'll print a load off and make sure each customer gets a copy along with their receit.

You sir, are the type of plumber I want when I'm old and gray and have to pay someone else to do my plumbing work!!