Re-using existing connection to a replacement Cylinder

[TB204]

I'm renewing my old indirect cylinder with a like for like replacement (albeit with an additional shower take off point). I intend replacing the cold feed and boiler connections with new pipe as they are pretty easy to replace.
My question is about reusing the existing hot water take off point at the top of the cylinder. My gut feel is telling me that using the existing pipe and olive could result in a poor seal and a leak.

I'd appreciate and tips or advice please.
Thanks.

 

[Deleted member 32524]

Best to cut off old olive and replace. Use a hack saw at 45 deg and cut through. Use a flat screwdriver to break it open near the end so you don't score pipe. Ptfe tape or jointing compound if you must use old olive.

 

[Burger]

I'm renewing my old indirect cylinder with a like for like replacement (albeit with an additional shower take off point). I intend replacing the cold feed and boiler connections with new pipe as they are pretty easy to replace.
My question is about reusing the existing hot water take off point at the top of the cylinder. My gut feel is telling me that using the existing pipe and olive could result in a poor seal and a leak.

I'd appreciate and tips or advice please.
Thanks.

Sometimes depends on the olive, if brass, then usually ok to reuse. Copper, I’d replace with a brass one.

 

[Welder]

Personally think you'd be extremely lucky for it to fit. IMHO best to simply cut out and install new. Use new T (with outlet pointing down) to take off supply to new shower.

 

[TB204]

Thanks for the advice - much appreciated. As I thought, best to remove the olive and provided the pipe is in good condition re-use with a new olive.

 

[Best]

Usually you will find tiny differences in the pipe to cylinder connections where the angle will vary or distance too short or to tight.
You won’t know exactly until you have new cylinder set in position.
Very often I am able to use existing olive. Use paste to help seal it

 

[king of pipes]

Pumped shower ? If so fit a Surrey flange for a separate hot shower connection

 

[TB204]

Thanks guys. The new cylinder is fitted with a specific shower connection so won't need to fit a surrey flange.

 

[Rob Foster]

let us know how you get on plse
centralheatking

 

[TB204]

Sorry for the slow response.
Will let you know how I get on. Unfortunately, the only way I can get to the cylinder is to remove the bath, so a bit of planning is required. (The previous owner of the house - a heating engineer - extended the bathroom and it now includes what was the airing cupboard. Unfortunately, the bath is fitted in front of the cupboard that houses the cylinder, so its a cow to get at. I am planning to carry out the work in a couple of weeks and will then re-fit out the bathroom.

As a final question. I want to be belt and braces with the connections on the boiler. As mentioned I will renew pipe where necessary and fit all new olives. I know Boss white is not a good idea as it can make future removal difficult. Any recommendations on a decent sealant to apply to the olives before tightening. Just to be sure.
Thanks.

 

[Burger]

Ptfe tape, loctite 55 I think it’s called also is another.

 

[Best]

For paste I now use V2 Lube.
It is expensive for just a one off job though.
Does potable water and gas and is none hardening, so joints later won’t seize after using it. Good shelf life too

 

[TB204]

Thanks Guys.
I should have said cylinder in my above post. Not boiler. Given how tricky it is to get to, I'll use the best sealant available.
Many moons ago I worked for a precision engineering company on medical anaesthetic tables and all the pipework used compression fittings and we never used anything on our olives. But they were copper olives which I preferred. These days I've had the odd problem with brass olives.

 

[Best]

Thanks Guys.
I should have said cylinder in my above post. Not boiler. Given how tricky it is to get to, I'll use the best sealant available.
Many moons ago I worked for a precision engineering company on medical anaesthetic tables and all the pipework used compression fittings and we never used anything on our olives. But they were copper olives which I preferred. These days I've had the odd problem with brass olives.

Brass olives are actually better than copper if good quality and onto copper pipe.
Copper olives tend to be very soft, which might seem ideal, but can flatten in too much and also allow movement on hot pipes causing slight weeps eventually.

 

[TB204]

Yes, I guess there is something in that. Although some of the problem with copper can be caused by over tightening. These were cold gases with no heat involved.

 

[ShaunCorbs]

Cheap fittings these days arnt built to spec if you used all branded fittings eg conex Yorkshire etc you wouldn’t need any paste

 

[TB204]

Yes, there's an awful lot of cheap crap around. In this instance, I am connecting directly to the cylinder which has 22mm and 28mm compression fittings. The cylinder was made by Newark cylinders in the UK to the dimensions I gave them to match my old cylinder with the addition of a 22mm shower take off point (its a bullet cylinder 350 dia x 1500 high). So in this instance I'm hopeful all will be to spec.
In my original question I was concerned about using existing pipe/olive for the hot water take off. But I'm going to replace the olive and provided the pipe is undamaged will then re-use. All other pipe work will be replaced. Given the awkward position of the cylinder and its associated pipework, I'm trying to be belt and braces. Hence the question of paste, although in an ideal world I know I shouldn't need it (not wishing to open a can of worms here)

 

[Best]

When you get a weep at a compression joint and you give it another nip up, and another, .... and then the drip appears again, you will wish you had used paste.
Can also be a lot to do with condition or type of pipe.
As I often say, - when you see some slight corrosion on a brass nut or find it seized, then it has been leaking slightly.

 

[TB204]

Hear what you're saying.
Belt and braces (a little paste on the olive) it is.