Calorifier pressure relief/ drain valve

[Alyssa]

Calorifier (Isotemp) pressure-relief/drain valve has started to leak excessively and I plan to replace it. I have two questions...
1) It screws into the cylinder and has a metal "T" screwed off it before joining up with the blue plastic pipework. It looks like it has some kind of compound/sealant on the screw threads. What should I use when I replace or can I simply use PTFE tape......bearing in mind that the valve and T joint need to be aligned???

2) Some of the plastic pipework needs to be removed to get access. I believe the elbows and T joints are "push-fit" type (they are certainly not compression or solvent "welded" joints).
Can they simply be pulled apart?? Can they then be re-inserted...or do I need to replace them??

Thanks

 

[chrisc]

1 PTFE tape or plumbers compound
2 before pulling the pipes off you have to push the covering 'ferrule'away from the removal direction to release the tube.(push the ferrule towards the T piece whilst pulling pipe away.)they are re-usable

 

[aluijten]

I've had exactly the same thing this year and had to remove all the fittings from the Isotemp. This proved to be a nightmare as the 90 degree fittings were actually fixed with loctite permanent sealant. It took me approx 2 hours (no joke) hammering on a spanner attached to the fitting to work them loose. By that time I was afraid the bashing killed had the calorifier. Thank God it didn't, but I used PFTE tape to put new fittings on the thing. This seems to work quite OK (also after 5 weeks of cruising).

I had to remove all fittings to get the insulation off because the leaking in my case was actually not the pressure relieve valve but a faulty weld that had been there al the time already (15 years) and had become worse over time.
So what begun as a hour-job ended into a 2 weeks job.
I hope your fixing will be less problematic.

Cheers,

Arno

 

[Piddy]

I have the same problem too.
I plan to simply connect a pipe (with a new pressure relief valve) to the outlet of the old valve and route it somewhere I can collect the water without it disappearing under the engine. That way I can monitor the amount of water I lose. This season - if I'm right - it has been more than a gallon during a weekend and the freshwater pump has been running when it shouldn't.
Obviously I will use the same pressure valve so keeping within the spec of the tank without the pain of trying to get the old one out.

Cheers

 

[snowleopard]

Push-fit plumbing

Most but not all push-fit joints are removable. The ones that aren't are often used by professional plumbers because they are a bit cheaper. Non-reusable ones are generally grey in colour.

To dismantle the normal type you generally press the collar around the pipe back into the body of the fitting then ease the pipe out. The commonest type in current use is Speedfit. They are lockable which can be a pain if you don't know how to release them. They lock by screwing the outer sleeve of the fitting clockwise until it is tight against the body of the fitting. To unlock, unscrew (anticlockwise) until there is a gap of around 1mm betweent he sleeve and the body. When the turning becomes stiffer, stop! If the pipe still won't come out you can dismantle the fitting completely by continuing to unscrew against the increased resistance and the sleeve will come off. Note the position of the O-ring and plastic washer for re-assembly.

For non-reusable fittings, unscrew the sleeve as described above. You will uncover the s/s barbed ring that holds the pipe in. This has to be cut, then you throw the whole fitting away.

Remember when re-assembling to make sure that there is an insert in the end of the pipe (doesn't apply to copper pipe) or it WILL leak!

When pulling pipe out of Speedfit fittings the insert often gets left behind. You can remove it by dismantling the fitting or just shove the pipe back in and it will re-seat.

Hope that helps.

One other thing - NEVER stick your finger in the end of the fitting, there are sharp blades in there!