Water hose pressure reducing limitingregulator

[Anseo]

As a folow on from Buckman's comment ("Does it have a pressure limiting regulator fitted?") posted in the "ExpandingRetractable Water Hose" thread.

How does a water pressure reducerlimiter work?

I undersgtand that reducing the water flow (via a tap) is not the same as reducing the water pressure.

Can someone give explanation please..

Cheers.

 

[ProfJohnL]

Hello Anseo,

When Carver first introduced the "waterline" it consisted of a reinforced food grade hose with clip connect system just like the garden hose connectors which coupled it to a tap, but the end that connected to the caravan had a water pressure reducer.

Here is the basic Dereve pressure reducer the one Carver and later Truma used on the Waterline and Ultraflow mains water connection products. Carver had it custom moulded to connect to the Crystal inlet fittings.

https://bonut.co.uk/pressure-regulators/
The pressure reducer does limit the pressure to prevent the normal mains pressure from blowing the caravan's internal pipe work.

The system did work, but it did sometimes have few drawbacks. Firstly whilst it limited the pressure effectively, some people found it also did not provide as much flow as some of the submersible pumps. And if the sites water system was limited for example it could not supply all the taps at the same time, it meant some times you might not have water when you want it.

There was also the nagging concern about what might happen if the pressure reducer failed and mains pressure was supplied to the caravan...I have it on good authority from a ex Carver Service Engineer that only one was returned having failed that way.

In my view the more dependable system is to use a float or Torbeck valve fitted into an external water container in conjunction with the caravans normal submersible pump. This ensure good pumped flow, localised storage of water when the mains can't deliver the full demand, and it removes the need for a pressure reducer valve.

The only down side is you have to have the means to get rid of the waste water.

 

[Buckman]

Basically if you connect a water hose direct to the caravan without the pressure reducer, you may blow off the water pipes in the caravan. You get around this by having the correct hose with a reducer but that defeats the objective you what you were trying to do. The other way is use a float in the aquaroll that shuts off the mains water and you use the normal pump for water into the caravan.

 

[Anseo]

I would like to reduce the water pressure at the supply end when using one of the retractableexpandable hose systems.

Would reducing the water pressure be more beneficial than reducing the flow rate so as to avoid stressing the internal membrane in said hose?

I have found that the internal membrane is the component that over-stretches and causes leaks, particularly at connector joints.

Thanks all.

 

[Anseo]

I tried looking for water pressure reducerlimiterregulator on Aliexpress without success, I am probably using the wrong terminologydescription in my searches, anyone know what the chines website suppliers call them?

Aliexpress are typically one quarterof the price for hose pipe adapters etc. compared to the usual UK sellers.

Ta all.

 

[ProfJohnL]

Hello Anseo,

The correct term is water pressure regulator.

I personally would be quite wary about sourcing such a component from the far East without having conducted tests on it to unsure it does do what you want and does it safely.

Many plastic colourants use poisonous chemicals, (Arsenic and Cyanide to mention just two) which do leach out of the plastic and will contaminate the water passing through them and may cause an unpleasant taste. Some of these chemicals will be absorbed by the Human body and effectively cumulatively stock piled in the bodies tissue. These may over time reach a critical level that can cause medical problems. Hence it is really important to only use food or potable water grade products, from reliable sources you can trust. What price safety for a few tens of pounds.

Whenever a fluid (such as water) passes through a relative narrow pipe the friction the pipe walls generates with the water trying to pass by opposes the flow and creates a pressure drop along the length of the pipe. The longer the pipe the greater the pressure drop, and in practice a 30 or 50ft garden hose can reduce a health flow from a tap to a mediocre flow at the end of a hose. If you place the regulator at the tap end, there is a danger the lower pressure in the pipe will be all used up to overcome the inherent resistance of the pipe leaving you with and inadequate pressure and flow at the caravan.

For that reason you need to keep the pressure as high as possible for as long as possible before applying a regulator. This is why virtually all the retail solutions fit the regulator at the caravan end and not the tap end of the pipe.

One of the characteristics of these expandable hoses is the internal pressure will cause the hose to expand to its full length. This could prove a problem especially if you are close to the tap, the hose will move quite a lot as the pressure changes. This could be a trip hazard to you or your neighbors. You will have to find some way of controlling this live snake. It is also one of the reasons the commercial products all used reinforced or multi-wall products. The pressure related movement is much reduced and is more easily managed.

 

[Sproket]

John,
Have a read of this.

 

[ProfJohnL]

Thank you Sproket.

Note the regulator is fitted as close as practical to the caravan. The use of a domestic type product also probably helps keep the flow rate acceptable.

The knurled knob would be a very attractive thing to tweak for someone with mischievous or malicious intent. For a more tamper proof solution, the PRV could be mounted inside the caravan, and a standard brass hose connection somewhere on the outside using proper mains pressure rated pipework.

Further down in the comments section, a reference was made to having an electrically operated valve on the system. This I hadn't thought of, but if it were a 12V solenoid valve then triggering it from the taps micro switches or a pressure switch could be a solution - BUT the valves have a snap action, which could produce some undesirable water flow characteristics, A motorised ball valve would be a kinder flow control.

e.g. http://www.solenoid-valve.world/other-products/ball-valves/ABVM04S

But my main concern would be effects of freezing on the PRV, Its quite likely the action of any ice would be to stretch the internal diaphragm probably rendering it useless and potentially putting mains pressure on the caravan pipework.

 

[Buckman]

Thank you Sproket.

Note the regulator is fitted as close as practical to the caravan. The use of a domestic type product also probably helps keep the flow rate acceptable.

The knurled knob would be a very attractive thing to tweak for someone with mischievous or malicious intent. For a more tamper proof solution, the PRV could be mounted inside the caravan, and a standard brass hose connection somewhere on the outside using proper mains pressure rated pipework.

Further down in the comments section, a reference was made to having an electrically operated valve on the system. This I hadn't thought of, but if it were a 12V solenoid valve then triggering it from the taps micro switches or a pressure switch could be a solution - BUT the valves have a snap action, which could produce some undesirable water flow characteristics, A motorised ball valve would be a kinder flow control.

e.g. http://www.solenoid-valve.world/other-products/ball-valves/ABVM04S

But my main concern would be effects of freezing on the PRV, Its quite likely the action of any ice would be to stretch the internal diaphragm probably rendering it useless and potentially putting mains pressure on the caravan pipework.

Using a pressure reducer on a retractable hose may reduce its lifespan even further plus it needs to be fitted in line. I am not sure how it could be connected up in line and even whether it can be done?

 

[ProfJohnL]

...
Using a pressure reducer on a retractable hose may reduce its lifespan even further plus it needs to be fitted in line. I am not sure how it could be connected up in line and even whether it can be done?

Why would using a PRV reduce its life span any more than say a trigger spray, what is your thinking?
In the case of a retractable hose I agree it would be difficult to fit an PRV within in the length of the hose, but I have suggested it should at the caravan end.

 

[Buckman]

...
Using a pressure reducer on a retractable hose may reduce its lifespan even further plus it needs to be fitted in line. I am not sure how it could be connected up in line and even whether it can be done?

Why would using a PRV reduce its life span any more than say a trigger spray, what is your thinking?
In the case of a retractable hose I agree it would be difficult to fit an PRV within in the length of the hose, but I have suggested it should at the caravan end.

I am not sure if the hose can take the pressure which is why its life span may be reduced. Those hoses have thin walls. I doubt if you could fit the pressure reducer where it plugs into the caravan as it will have o be one from Whale or Truma and most of them it appears that the hose cannot be fitted afterwards. TBH I think a retractable hose is a non starter unless used in conjunction with Aquaroll mains water adaptor.

 

[Anseo]

I appreciate the replies, but I think I may not have explained clearly.

I will use a retractable hose in conjunction with a torbeck valve in the aquaroll.

I want to fit a pressure reducer at the end that connects to the site water supply tapfawcett.

This is so that I have a reduced water pressure within the retractable hose, a reduced water pressure within the length of the retractable hose will not adversely affect the function of caravan water outlets.

Thanks,
Anseo.

 

[Buckman]

I appreciate the replies, but I think I may not have explained clearly.

I will use a retractable hose in conjunction with a torbeck valve in the aquaroll.

I want to fit a pressure reducer at the end that connects to the site water supply tapfawcett.

This is so that I have a reduced water pressure within the retractable hose, a reduced water pressure within the length of the retractable hose will not adversely affect the function of caravan water outlets.

Thanks,

Why worry about a pressure reducer then. Just do not open the tap full on. Open it just a bit to trickle into the aquaroll. Problem solved.
Anseo.

 

[ProfJohnL]

...I am not sure if the hose can take the pressure which is why its life span may be reduced. Those hoses have thin walls. I doubt if you could fit the pressure reducer where it plugs into the caravan as it will have o be one from Whale or Truma and most of them it appears that the hose cannot be fitted afterwards. TBH I think a retractable hose is a non starter unless used in conjunction with Aquaroll mains water adaptor.

Hello Buckman,
I know the question about how well these hose's lasts is not proven yet, but fitting a pressure reducer at the down stream end is no different to the hosepipe being used with a spray or jet trigger handle. In each case the full length of the hose will experience the full pressure from the tap when the flow is stopped, so in this instance the life of the hose pipe should be the same.

However if the pressure reducer were fitted at the upstream end of the pipe, then the pipe would only experience the reduced pressure which it might survive for longer, but the water will still have enough power to cause the pipe to expand almost to its limit.

As for fitting the hose and PRV so it will couple to existing inlet systems, Carver and Truma did this by having a turnkey moulding created for the Dereve PRV. So if there is sufficient demand then supplies are more likely to stump up the cost of making propriety parts to do the job. Until then ingenuity will have to be applied.

The characteristic of a collapsible hose to expand when it is filled with water will applies equally to the PRV concept and the Aquaroll mains water adapter. as the pressure changes the hose will writhe about like a snake creating a potential trip hazard.

 

[Anseo]

Why worry about a pressure reducer then. Just do not open the tap full on. Open it just a bit to trickle into the aquaroll. Problem solved.

If you refer to my original post, my question was about water pressure reduction, not water flow reduction.

ref: "I understand that reducing the water flow (via a tap) is not the same as reducing the water pressure".

Anseo.

 

[ProfJohnL]

Quite correct Anseo.

Buckman. If a mains water tap is only cracked open then the flow will be severely restricted. If the out flow is stopped, the now closed system will begin to pressurise to the same mains pressure that exists on the up stream side of the tap. If that were to be allowed to build up inside the caravan pipework it would definitely damage some of the appliances and fittings.

 

[Sproket]

ref: "I understand that reducing the water flow (via a tap) is not the same as reducing the water pressure".

Anseo.
You could try one of these at the tap end there not a lot of money and less likely to be messed around with.

 

[Anseo]

PROF:
A simple and clear exampleexplanation, thank you.

SPROCKET:
Just the ticket, I will order a couple of those, thank you.

John

 

[Buckman]

Quite correct Anseo.

Buckman. If a mains water tap is only cracked open then the flow will be severely restricted. If the out flow is stopped, the now closed system will begin to pressurise to the same mains pressure that exists on the up stream side of the tap. If that were to be allowed to build up inside the caravan pipework it would definitely damage some of the appliances and fittings.

As said by Anseo they will be using an aqua float in the aquaroll and it will not go direct to the caravan so no issue.

 

[Anseo]

ref: "I understand that reducing the water flow (via a tap) is not the same as reducing the water pressure".

Anseo.
You could try one of these at the tap end there not a lot of money and less likely to be messed around with.

Hi Sprocket,

I ordered these, a pack of 2 and took the 15psi option, £2.76 delivered:
Will put them to the test on my next outing.

https://www.aliexpress.com/item/2pcs-Pressure-Regulator-Reducer-Regulators-Reduce-Incoming-Water-Pressure-3-4-FHT-x-MHT-Hose-Fitting/32952114292.html?spm=2114.search0104.3.149.664d6497DlwfnN&ws_ab_test=searchweb0_0,searchweb201602_5_10065_10068_10130_10890_10547_319_10546_317_10548_10696_10190_453_10084_454_10083_10618_10307_10820_10303_537_536_10902_10059_10884_10887_321_322_10103,searchweb201603_45,ppcSwitch_0&algo_expid=311ff12b-42f1-4347-9cc7-04da602d6aef-22&algo_pvid=311ff12b-42f1-4347-9cc7-04da602d6aef&transAbTest=ae803_4

 

[Sproket]

ref: "I understand that reducing the water flow (via a tap) is not the same as reducing the water pressure".

Anseo.
You could try one of these at the tap end there not a lot of money and less likely to be messed around with.

Hi Sprocket,

I ordered these, a pack of 2 and took the 15psi option, £2.76 delivered:
Will put them to the test on my next outing.

]https://www.aliexpress.com/item/2pcs-Pressure-Regulator-Reducer-Regulators-Reduce-Incoming-Water-Pressure-3-4-FHT-x-MHT-Hose-Fitting/32952114292.html?spm=2114.search0104.3.149.664d6497DlwfnN&ws_ab_test=searchweb0_0,searchweb201602_5_10065_10068_10130_10890_10547_319_10546_317_10548_10696_10190_453_10084_454_10083_10618_10307_10820_10303_537_536_10902_10059_10884_10887_321_322_10103,searchweb201603_45,ppcSwitch_0&algo_expid=311ff12b-42f1-4347-9cc7-04da602d6aef-22&algo_pvid=311ff12b-42f1-4347-9cc7-04da602d6aef&transAbTest=ae803_4

https://www.aliexpress.com/item/2pc...-9cc7-04da602d6aef&transAbTest=ae803_4[/quote
Back in 2016 at the great woosie fest i had a blue food safe layflat hose that was wound onto a reel but unwound when being used, I couldn't understand why at times trying to fill my onboard tank that it would spring a leak just like a fire hose through very fine pin holes. When i got the van back on it's seasonal pitch my water tap was quite a way from the van and it did the same when i tried to fill my tank, so i originally bought a one of these to try and identify what was happening I put a male & female hose connector on so that it could be used at either end of the hose, it turned out that the mains pressure could be as high as 80psi or as low as 20psi depending on if any other taps on site were being used at the same time, so i used it at the tap end for a while and it cured the problem, at the start of the new season i found and fitted one of these to the end of some new solid food grade hose and it's been ok since.