Sealing small fuel leak

ennisjim

Hi,
I have an indoor (utility room) oil condensing boiler and there is very slight leak where the incoming fuel pipe connects. Even though the leak is very slight the smell is quite bad in that room. I asked my plumber to sort it out and he did reduce the leak but did not sort it completely. It's getting hard to get him back to sort out these little issues so I thought I'd have a go myself. Some questions

can I use white plumbers tape to help seal the connection or is it unsuitable for sealing oil pipes, eg. does diesel/kerosene break it down ?

is there some kind of sealer/putty/etc I can use if tightening and plumbers tape doesn't quite finish the job ?

any other suggestions would be appreciated

Thanks

ircoha

Any chance of a picture?

If you do we may be able to advise u a bit more

I hope I am wrong here but it seems to me that
either
the thread is wrecked here: maybe because of a metric/imperial mismatch, or the pipe was cut too short,
or is not approaching the joint straight on
or was over-tightened
or an metric ring was used on am imperial fitting.

Irish instantor fittings are 1/2 inch or 12.7 mm
Most continental and uk fittings are 15mm

I am not a plumber but the basic design for most domestic plumbing fittings revolves about the compression ring.
if you don't seal the joint where the ring fits around the pipe and where it seats into the fitting it is very difficult to seal.

Putting stuff, particularly white tape, on the threads is last gasp stuff.
The more u put on the harder it is to tighten

The compression ring should be doing the sealing and the function of the threads is to apply sufficient pressure on the ring to, as the name suggests, 'compress' the ring.

There are compounds available for using with oil.

My instinct here is to think in terms of replacing the last section of pipe, maybe from the oil filter, maybe with a flexible hose:

these people may be of help
http://www.boilercare.ie/

ennisjim

Thanks ircoha for your detailed reply and suggestions. I'll follow up on these.

I'll try to get a picture too and post it. Actually the connection is from incoming fuel line to the bottom of a 'tiger loop' which was plumber was not too familiar with so there is the possibility that there may be a mismatch on the diameter. I'll check this up too.

JamesM

What ircoha said !
And just to add, using white tape, putty, or anything you apply from the outside does not work - the oil will get through.
If tightening the fitting does not work, you must take it apart and try ptfe tape - otherwise new rings or complete fittings.
Jim.

John mac

ptfe tape on the threads wont work.
the seal is between the rings and the nut as already stated thread is only to tighten nut.

if fitting has been overtightened the best way is to cut out the offending piece of tube,
and remake the joint using a new ring.

if the pipe isnt long enough to make the connection you may have to put in anoother piece.
cutting the pipe again 200mm or so from the end and rejoining with a 310 fitting. (straight coupler)
then you should have enough to reconnect to the boiler.
ensure you have the correct size fittings.. (compression fittings do not need to be forced.)

JamesM

Ptfe on the back of the ring will work if the ring has been compressed too much. But, if this is a new fitting, that should not be the problem. I'm not great on fittings but, there is probably something like a 611 screwed into the 'tiger loop' on the inlet side and a nipple and flexible oil line out the other side. Any of the rings or threads could be leaking.
Jim.

ennisjim

Hi Lads,

Plenty to think about and thanks for the wisdom. Sounds like I should give the tape a try and see how the fitting works and where best to apply the tape. If this doesn't work I'll try John's advice to make a new connection.
Just a question re. tigerloop and the fitting procedure. I suppose the idea is to turn off valve at tank first, then open the connection catching any fuel in a container but I guess there shouldn't be much - tank is below or close to same level as boiler in utility room. Then after remaking the connection do you know if I need to do anything special to get tigerloop working again ? prime it somehow ?

Thanks