Calorifier pressure valve

[abraxus]

Or, alternatively, run a little water out of the hot tap to reduce the calorifier pressure, with the FW pump turned off, after about the 1st 20' of engine running - a rather simpler and more cost-effective solution which has worked well for me for the last 6 years.

Forgive me if I misunderstand, but if you're going to do that then you might just as well leave the prv to do its job and reduce the pressure by releasing a little water. That would seem simpler as it requires even less user intervention, especially if you route the water overboard or into a container.

 

[VicS]

Forgive me if I misunderstand, but if you're going to do that then you might just as well leave the prv to do its job and reduce the pressure by releasing a little water. That would seem simpler as it requires even less user intervention, especially if you route the water overboard or into a container.

I'd regard the prv as a safety device rather than something installed to routinely control the maximum pressure.

 

[nigelmercier]

I may be wrong, but don't PRVs need to be occasionally re-seated by rotating the spigot?

 

[wiggy]

Thanks Danny, thanks VicS. I can feel an expansion tank coming on! Another job on my list of to do's.

I have one sat in the garage if you want it and are near Brighton/ Gosport PM me.

 

[David2452]

One of the things that puzzles me is the repeated use of 3 bar PRVs, when one checks the working pressure of most calorifiers it is well above that level, PRVs are available in many blow off values and higher rated ones are fitted as standard to some calorifiers.

 

[captainboo]

I may be wrong, but don't PRVs need to be occasionally re-seated by rotating the spigot?

Only if it is weeping due to debris caught under the seal. Hopefully it will help to flush the valve seat clean. Should not be necessary on a correctly setup system and if done unnecessarily may even cause weeping by allowing debris to be caught in the valve seat. If it ain't broke.....

 

[charles_reed]

Ok, that saves the £20 for an expansion bottle, but if you think such a palaver every time you start the engine is "simpler" you're f'ing mental!

(Or possibly you write for the Top Tips page in Viz )

Pete

Not really mental, though your boorishness does raise my BP.

If - you have insufficient room to fit an expansion tank,
If you are sufficiently half-witted to not be able carry out a simple procedure
If you have no better things on which to waste your time and substance

Well go ahead and fit your tank.
I'd certainly not rely on the PRV as my sole calorifier relief, IMHO the added complexity of a NRV, the associated pipework and the expansion tank which will inevitably perforate, being my experience of expansion tanks.

But then, Pete, I was once as intemperately single-minded as you, but have had the good fortune to mature a little.

I guess, with 183 nights and 1383nm last year on my boat and having been sailing my own boats for 38 years, I might have some leeway in not having to agree with your opinions.