Water Pressure Regulator

[MtB]

You wont be over riding the pump switch as you will be interrupting the supply to the pump before it cuts out, Just like switching the breaker off when the pressure reaches what you want,If the switch failed to operate the pump switch would cut its self off as normal. Yes its 240 volt but that in its self is not a reason for not using it on 12 volts DC

 

 

Other than switching 12v means it will quite probably be switching a higher current than if controlling a 240v appliance.

[WotEver]

 

Other than switching 12v means it will quite probably be switching a higher current than if controlling a 240v appliance.

And depending on the speed of the contact break it could arc itself to death. Better to find a DC pressure switch.

 

Tony

[Chewbacka]

And depending on the speed of the contact break it could arc itself to death. Better to find a DC pressure switch.

 

Tony

If you can not find a reasonably priced DC switch that you are happy using, then you could use the pressure switch to switch the power (12v) to a DC relay with the DC relay switching the pump on and off.

 

Just put "double pole pressure switch" into ebay and a huge range of switches with various pressure ranges and pipe fittings will appear.

12V relays are also fairly cheap at about £1 also on ebay though it may take a month to arrive from China

Edited April 23, 2016 by Chewbacka

[PeterDHS]

Thanks again for all your help.

 

Peter

[PeterDHS]

I've been thinking about what the Boilerman said regarding the importance of checking if a NRV is incorporated in the calorifier, or indeed elsewhere. The suggestion was that I disconnect at the tank and see how much water falls out !!

My idea is that I simply (starting with a cold engine) open the cold sink tap but with the pump switched off. After the usual dribbles I put a container under the tap and then run the engine up to temp and measure how much water if any is in the container. I would then repeat the process from cold but using the hot tap. This should show whether I have an NRV preventing backflow of hot down the cold pipe and also the water in the container would show the amount of expansion in the system. Yes/No ?

 

Peter

[ditchcrawler]

I've been thinking about what the Boilerman said regarding the importance of checking if a NRV is incorporated in the calorifier, or indeed elsewhere. The suggestion was that I disconnect at the tank and see how much water falls out !!

My idea is that I simply (starting with a cold engine) open the cold sink tap but with the pump switched off. After the usual dribbles I put a container under the tap and then run the engine up to temp and measure how much water if any is in the container. I would then repeat the process from cold but using the hot tap. This should show whether I have an NRV preventing backflow of hot down the cold pipe and also the water in the container would show the amount of expansion in the system. Yes/No ?

 

Peter

sounds good to me

[PeterDHS]

Ok.

I have done my test albeit under unequal circumstances and the results are...........on the hot tap after a run of 4 hours I collected just short of a litre.....on the cold tap after just an hour moored 'battery charging' I collected 0.7 litres.(both from cold starts).

Allowing for the different running times I am fairly confident that I have no NRV, or at least if there was an NRV there would have been a much bigger difference in volumes.

I have estimated the calorifier capacity at a bit less than 55 litres and am told that water expands 2 percent over 50 degrees rise in temp so a litre expansion is in the ballpark.

 

Bad news is I have fallen and jiggered my knee so the plumbing alterations are on hold............sod's law !

Peter.

[ditchcrawler]

Ok.

I have done my test albeit under unequal circumstances and the results are...........on the hot tap after a run of 4 hours I collected just short of a litre.....on the cold tap after just an hour moored 'battery charging' I collected 0.7 litres.(both from cold starts).

Allowing for the different running times I am fairly confident that I have no NRV, or at least if there was an NRV there would have been a much bigger difference in volumes.

I have estimated the calorifier capacity at a bit less than 55 litres and am told that water expands 2 percent over 50 degrees rise in temp so a litre expansion is in the ballpark.

 

Bad news is I have fallen and jiggered my knee so the plumbing alterations are on hold............sod's law !

Peter.

Well its something to think about while your crocked, hope things soon improve for you.

[PeterDHS]

Just an update from a grateful OP-

 

I modified the system as discussed, adding a pressure control valve and an expansion tank and everything is now fine.

 

However the first time I ran the engine up to hot the calorifier PRV still weeped water.......so I checked the dial on the PCV and it said 2.2 bar pressure was leaking past a the 3 bar calorifier PRV.....obviously faulty (not gunged up ).

So I changed that and now OK.

 

Guess the moral is to check the basic things first rather than find over-engineered solutions to the symptoms.

 

Thanks all, peter.

[MtB]

PRVs are notorious for failing to close once operated. In the world of boilers it is considered lucky not to have to replace a PRV that has operated once.

[ditchcrawler]

PRVs are notorious for failing to close once operated. In the world of boilers it is considered lucky not to have to replace a PRV that has operated once.

When I worked for a living if we ever had a pressure release valve lift it was removed and serviced. you never know what gets on the faces when they open.

[PeterDHS]

Hang on a moment.

I'm pretty sure that good advice says to 'click' the PRV every few months to stop it from sticking and building up crud. Surely this is the same in efect as the valve opening and therefore your saying that most boats on the waterways are sailing about with u/s PRV's ???

[MtB]

Hang on a moment.

I'm pretty sure that good advice says to 'click' the PRV every few months to stop it from sticking and building up crud. Surely this is the same in efect as the valve opening and therefore your saying that most boats on the waterways are sailing about with u/s PRV's ???

 

 

Check who is giving this advice...

 

Sellers of PRVs I predict.

[ditchcrawler]

 

 

Check who is giving this advice...

 

Sellers of PRVs I predict.

If it dosent pass how can the seats get gummed up?

[MtB]

If it dosent pass how can the seats get gummed up?

 

 

How can you test it using the 'click test' mentioned, without it passing?

[ditchcrawler]

 

 

How can you test it using the 'click test' mentioned, without it passing?

Sorry I am lost on that one.

[Alan Taylor]

 

No need to patronise the OP, most of what they need to know was covered in a topic a mere couple of days ago, which you surely must have seen:

 

http://www.canalworld.net/forums/index.php?showtopic=84118&page=2#entry1807138

 

 

MtBs signature may be somewhat ironic...

 

cheers, Pete.

~smpt~

are the accumulator and expansion tank marked the same piece of equipment?

What's the smallest that can be fitted and where can I get them?

 

sorry to hijack the thread.

Edited July 13, 2016 by Alan Taylor

[raymondh]

are the accumulator and expansion tank marked the same piece of equipment?

What's the smallest that can be fitted and where can I get them?

 

sorry to hijack the thread.

Above shown on the Shurecal website

 

We have 40psi max (set by remote pressure switch) 4US GPM flow rate and the calorifier came fitted with a 4 BAR PRV

 

Works for us

 

Ray