Pressure relief valve

[Shaino]

Hi All,

I'm planning to use mains water quite often and I am a bit concerned about pressure reducer failing so I'm thinking about installing a pressure relief valve which would automatically drain if the water pressure exceeds the acceptable level for caravans.

Does such thing exist for caravans, if yes - which one would you recommend?

Thanks!

 

[Mr Plodd]

If tge pressure reducer fails and the relief valve works then water will continue to flow until the supply is cut off. That could be a lot overnight!

 

[Shaino]

If tge pressure reducer fails and the relief valve works then water will continue to flow until the supply is cut off. That could be a lot overnight!

Either that or risking damaging van's pipes and having the same leak but inside

 

[Buckman]

We have been using direct mains water for years and so far we have not had any issues. Gave up worrying about flooding the caravan.

 

[ProfJohnL]

Some caravanner's are happy to use the water supply systems which use a pressure regulator valve built into the hose pipe. In general these do seem to be fairly reliable, and don't allow excess pressure through. That's fine as long as they do continue to work properly. But I know from professional experience, that when they do fail, the consequences are very disruptive and distressing to the caravanner, and can be expensive, when water heaters need to be repaired or replaced, as they are not waranteed against over pressure supplies.

Also because of the the majority of the pressure regulators are of a similar size, they have a lower flow rate through the valve, and several caravanner's have reported poor flow rates compared to their normal water pumps.

In addition, there have also been incidents, where poor flow and pressure have been caused by the camping sites pipe work that cannot cope with the maximum demand for water at peak times, obviously this is not the fault of the pressure reducer, but it's only caravanner's who use them that experience it.

There is an effective solution to all of the above, and that is to continue to use your water pump in a storage vessel next to the caravan, and using a float control valve to control the vessels filling from mains water.

Because the system is vented, if the pressure valve fails the water will only over flow the storage container, and not flood the inside of the caravan. Having typically 30 or more litres of storage will cover the inadequacies of the sites pipe work, and you maintain the flow delivery of water through the caravans pipe work.

A simple and demonstrably safer and better solution.

 

[Dustydog]

We discussed this subject to near death. Here it is. Enjoy😉https://forums.practicalcaravan.com/threads/water-inlet-fully-serviced-pitch.66226/

 

[Buckman]

We discussed this subject to near death. Here it is. Enjoy😉https://forums.practicalcaravan.com/threads/water-inlet-fully-serviced-pitch.66226/

Absolutely and getting tired of reading about it again and again with the same argument that direct mains is bad!

 

[ProfJohnL]

When a direct mains solution works that's fine. But when it goes wrong the consequences can be major. Since when has offering a low risk solution should be discouraged?

My comments are based on experience of having had to deal with the after effects where a direct mains has failed and flooded 5 caravans, and I know other organisations have also had small numbers of similar incidents.

Although it's a statistically low occurance rate, the consequences are major, and clearly it does lie on some caravanner's minds enough for them to raise the question so they deserve the answer and to be made aware of a very low risk viable alternative.

This forum is for all commers, old hands, and those fresh to caravanning and are new to the forum, just because you know the answer does not mean every reader has you own knowledge or values.

Schools would be pretty useless if teachers were limited to giving facts only once in their careers.

 

[Gozza2]

We rarely use service pitches but when we do, I use the "Prof Solution" - Prof's reasons for doing so make sense to me, and it's not like it requires any equipment that I don't already have anyway.

That said, I have wondered - just as an academic exercise - about a direct connection, but with a solenoid valve in the supply driven off the 12v supply that normally operates the pump? So the water can't flow into the van except under circumstances when the pump would be running if you weren't on a service pitch?

Like I said, it's a brain puzzle only for me - even if we were 100% service pitches I'd still carry the Aquaroll and pump in case of a site plumbing failure - but in the spirit of enquiry I'd be interested to know other people's thoughts?

 

[Buckman]

We rarely use service pitches but when we do, I use the "Prof Solution" - Prof's reasons for doing so make sense to me, and it's not like it requires any equipment that I don't already have anyway.

That said, I have wondered - just as an academic exercise - about a direct connection, but with a solenoid valve in the supply driven off the 12v supply that normally operates the pump? So the water can't flow into the van except under circumstances when the pump would be running if you weren't on a service pitch?

Like I said, it's a brain puzzle only for me - even if we were 100% service pitches I'd still carry the Aquaroll and pump in case of a site plumbing failure - but in the spirit of enquiry I'd be interested to know other people's thoughts?

We have not carried an aquaroll or wastemaster for the past year and are quite happy with our solution as we are there to enjoy our holiday and not to worry about a caravan flooding.

By the way I have been reliably informed that if for some reason a caravan did flood, if you tilt the caravan, a lot of the water would run out of the vents. The remaining water can then be soaked up with mop or rags and the caravan ventilated. Even if a caravan was flooded for several hours, damage should be minimal and a damp reading done a few days later may not show any trace of the flooding.

We are living proof that this is correct as we had an internal pipe burst on a previous caravan which flooded the caravan and we were on a fully serviced pitch connected to direct mains!

 

[ProfJohnL]

We rarely use service pitches but when we do, I use the "Prof Solution" - Prof's reasons for doing so make sense to me, and it's not like it requires any equipment that I don't already have anyway.

That said, I have wondered - just as an academic exercise - about a direct connection, but with a solenoid valve in the supply driven off the 12v supply that normally operates the pump? So the water can't flow into the van except under circumstances when the pump would be running if you weren't on a service pitch?

Like I said, it's a brain puzzle only for me - even if we were 100% service pitches I'd still carry the Aquaroll and pump in case of a site plumbing failure - but in the spirit of enquiry I'd be interested to know other people's thoughts?

It's a good idea, but it wouldn't stop excess pressure reaching the caravan if the prv failed and you activated the solenoid. You would also need to prevent the caravans pressure switch from inturupting the solenoid drive, as the snap action of the solenoid would likely cause unstable water temperatures when trying to mix for showers.

 

[ProfJohnL]

We have not carried an aquaroll or wastemaster for the past year and are quite happy with our solution as we are there to enjoy our holiday and not to worry about a caravan flooding.

By the way I have been reliably informed that if for some reason a caravan did flood, if you tilt the caravan, a lot of the water would run out of the vents. The remaining water can then be soaked up with mop or rags and the caravan ventilated. Even if a caravan was flooded for several hours, damage should be minimal and a damp reading done a few days later may not show any trace of the flooding.

We are living proof that this is correct as we had an internal pipe burst on a previous caravan which flooded the caravan and we were on a fully serviced pitch connected to direct mains!

There is nothing wrong with your experience, but it's your experience, and unusually for your luck, it obviously was not as bad as it could have been. Sadly it does not reflect the evidence from those who have suffered such failures. I have never said or suggested that Direct mains cannot work, it just does pose a risk of major disruption when it does go wrong, and for many it's a sensible precaution to avoid the risk.

Try telling a family whose holiday has just been ruined because a water pressure regulator failed and their caravan has not just flooded because of blown pipe joint, but has also knocked out their water heater, soaked bedding and clothing, made the electrics trip. These sorts of problems only arise when the caravan is usually being used in those few precious days of holiday time, so it's impact is far more stressful.

I came across one extreme case where a caravan had been stored in a back gardena at the end of the summer. and had been used as spare bedroom over the Christmas period. The owner didn't go any where near it until late February and discovered it sitting in quagmire caused an unrestrained leak (and the weather) but the bottoms of all the internal wood work had swollen and delaminated the bottoms of the exterior walls were soden and showing signs of rot, the floor was soft and uneven.

The evidence found the direct mains had been left connected and turned on. After disconnecting the hose, it was clear the regulator had failed. But the consequence had been the pressure built up in caravans system, and although the pressure relief valve on the water heater had activated, the flow of water overwhelmed the relief valve and the pressure continued to build until the water filter split causing the flood.

The caravan was of course written off.

 

[Buckman]

Surely it is up to the individual to decide what system they would like to use not instead of getting long procrastinated lectures on the merits of using direct mains or not? I am sure most people can eventually make their own decisions?

 

[Gozza2]

It's a good idea, but it wouldn't stop excess pressure reaching the caravan if the prv failed and you activated the solenoid. You would also need to prevent the caravans pressure switch from inturupting the solenoid drive, as the snap action of the solenoid would likely cause unstable water temperatures when trying to mix for showers.

I knew there'd be some reason why no-one was doing it!

 

[Shaino]

Surely it is up to the individual to decide what system they would like to use not instead of getting long procrastinated lectures on the merits of using direct mains or not? I am sure most people can eventually make their own decisions?

I'm not sure if there is something going on between @Buckman and @ProfJohnL but I personally don't find @ProfJohnL 's messages "procrastinated lectures"

 

[Dustydog]

I really do wonder why this discussion is just becoming another I know best syndrome. The previous thread I quoted earlier thrashed the matter to death.
IMO there is no right or wrong if the advice offered is commensurate with the caravan model concerned.
Buckman’s Buccanneer was , without doubt, designed by qualified engineers who understand caravan plumbing and user needs.
I see a lot of ancillary component for caravan manufacturers are also Members of the NCC. There’s a surprise! But they talk technical not what who thinks what.
Put simply if I had a modern newish Swift Bailey and they said use a direct water feed would I question them? NO!
I took the view in the previous comprehensive thread discussion both systems are perfect providing they are used in the context and advice given by the Caravan and plumbing makers .
My 15 year old is a bit delicate so the aqua roll mains adapter is best for me. BUT it doesn’t make the direct system undesirable if used as designed. AMEN!

 

[ProfJohnL]

I'm not sure if there is something going on between @Buckman and @ProfJohnL but I personally don't find @ProfJohnL 's messages "procrastinated lectures"

Thank you for your comment.

Please keep reading, and make your own mind up on which if any view of any subject has greater credence.

 

[otherclive]

I really do wonder why this discussion is just becoming another I know best syndrome. The previous thread I quoted earlier thrashed the matter to death.
IMO there is no right or wrong if the advice offered is commensurate with the caravan model concerned.
Buckman’s Buccanneer was , without doubt, designed by qualified engineers who understand caravan plumbing and user needs.
I see a lot of ancillary component for caravan manufacturers are also Members of the NCC. There’s a surprise! But they talk technical not what who thinks what.
Put simply if I had a modern newish Swift Bailey and they said use a direct water feed would I question them? NO!
I took the view in the previous comprehensive thread discussion both systems are perfect providing they are used in the context and advice given by the Caravan and plumbing makers .
My 15 year old is a bit delicate so the aqua roll mains adapter is best for me. BUT it doesn’t make the direct system undesirable if used as designed. AMEN!

Understand your view and the thread link you posted did comprehensively cover the topic but of course questions came from a member who hadn’t come across that thread. Unless a search reveals such links as yours it’s difficult to avoid some duplication of topics and views.

 

[Dustydog]

Understand your view and the thread link you posted did comprehensively cover the topic but of course questions came from a member who hadn’t come across that thread. Unless a search reveals such links as yours it’s difficult to avoid some duplication of topics and views.

Agreed but why start re writing the whole debate again rather than giving the heads up on a previously well thrashed out thread. I for one will welcome a new entrant reopening it.

 

[otherclive]

Agreed but why start re writing the whole debate again rather than giving the heads up on a previously well thrashed out thread. I for one will welcome a new entrant reopening it.

I cannot answer that one, best addressed by those who initially responded or someone who was aware of the thread and pointed the OP in that direction. Now where were we all in MIRO and MTPLM🤣

 

[ProfJohnL]

Please consider this from the OP's perspective.

The OP asks a question, and is offered an opinion, which does not discuss the pro's and cons which is what was asked for.

Having received a very one sided answer which stays on display in the thread, I believed it deserved a balancing comment so the OP is not being directed here there and everywhere trying to look for answers.

The OP ideally needs some evidence or explanation as to why the views differ. He is now in possession, of that information and can make a better informed decision.

This forum is not just for the old hands, who may already know the issues, and be board by them.

 

[Shaino]

I think it's quite interesting to note that even that the discussion diverged almost immediately from the original topic about "pressure relief valves" to "reliability of pressure reducers and risks associated" it's the link provided to a similar topic on the latter that has a comment from @ProfJohnL briefly mentioning that a pressure relief valve didn't cope with the pressure, which, in the end, concluded me to use the approach aforementioned with aquaroll.

It's still would be interesting to know about pressure relief valves for caravan though, just out of the curiosity now.

Thanks everyone participated!

 

[JTQ]

Even if a caravan was flooded for several hours, damage should be minimal and a damp reading done a few days later may not show any trace of the flooding.

Are there really any people who believe such a claim that flooding a caravan for several hours" cause minimal damage"?
It was in the forenoon of a first of April surely to be spun that one.

 

[ProfJohnL]

...
It's still would be interesting to know about pressure relief valves for caravan though, just out of the curiosity now.

There are Pressure relief valves used in caravans, but they are usually associated with water heaters in case they misbehave. I'm not aware of any other makes of caravan water pressure relief valves.

They are designed to relieve pressure by dumping water under the caravan, if the heater exceeds its maximum water temperature. Thus they are only every going to need to deal with the small flow of expansion water, probably less than 1 liter an hour. Most water pumps and direct connection water hoses are usually able to exceed 4 liters a minute, and consequently the heaters relief valve will quickly be overwhelmed by a failed pressure reducer valve flow and that would cause significantly raised back pressure in the pipework and other fittings and appliances.

 

[Dustydog]

A Eureka moment,
Why not use.an Automatic water shut off valve. Easily fitted in line with the feed hose. They can be set to cut off the flow on a time or flow basis. Maybe the direct fixing kit should offer one as an optional extra. ?