Rather than hijacking another post, I'll open another thread. This has all started when we had visitors, and the other lady talking to my lady about the caravan, got around to talking about washing their hair, and it appears there was not enough water pressure to wash out the shampoo. Well it so happened we have the same low water pressure problem off the mains as them. Well all we have to is buy another valve thingy.
Yes but which valve thingy are you talking about. So I have a look at the system, definitely less water pressure when on mains than on the in house pump, so test water flows, pressure limiting valve no problem, flow down at the water use end, yes a problem. So it appears that the pressure is restricted by the system tubing.
This also got me thinking about problems others I've read about with their water systems, blowing hoses, pump diaphragms etc. This I put down to the excess water pressure and water pressure is controlled by the "Pressure limiting valve", which means it must become faulty.
This valve, which is now being installed (I believe in new houses) limits the pressure within the system to 350KPA (51psi), so how high can the mains water pressure get to? having a look on the net the highest I read was 1200KPA (174 psi), over 3 times the system pressure of the van!
So how much pressure can the John Guest fittings take, between 100 and 150 psi depending on temperature, so on a hot day with a faulty pressure limiting valve things could get interesting.
I had intended to fit a water filter and new PRV at the rear of the van where water usage was needed, having brought the filter, I looked up the pressure rating for it, 87 psi, bummer can't use it on the mains side.
Also the pump install instructions say to use tubing with an ID of 12mm or else pressure drop will occur, and noise will occur. What's the tubing size 12mm OD, with about a 8mm ID so no wonder I have noise and low pressure.
Have a look at your water main input point
9 out of 10 the wasp are filling it up with mud
I have an one way hose connector fitted to mine intake point
so that solves that problem
Just have a look
So how much pressure can the John Guest fittings take, between 100 and 150 psi depending on temperature, so on a hot day with a faulty pressure limiting valve things could get interesting.
The John Guest plumbing will take much more pressure than the hot water systems. It will be the tank there that you destroy if you put too high a pressure into the system.
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PeterD Nissan Navara D23 diesel auto, Spaceland pop-top Retired radio and electronics technician. NSW Central Coast.
So resorting to plan "B", and am running a 12mm ID tube from the pressure limiting valve, which is at the mains connection, down to the rear end and teeing it into where the most water pressure is required.
Just to correct a statement I made in the opening post, I said that houses were having a PLV of 350kpa installed. That's not correct, the pressure limiting valve for houses is 500 or 550kpa (80psi) whereas the PLV for RV's is 350kpa (51psi), why I dunno.
Had a look at what the pressure limit for the hot water service in my van is, it is 150psi (1034kpa), that's when new, don't know what the relief valve is set at.
Having installed a 12mm ID tube from the PLV 6meters up to go in near the same entry point as the Shuflo pump, the flow rate went up from 3.51 lt./min to 4.72 lt./min, while the flow rate when using the pump is 5.88 lt./min. Now that is water coming out from the shower rose.
Interesting though the flow rate at the outlet of the PLV is 13.95 lt./min, that is no flow restrictions or head from the shower etc.
Checked, the water heater relief valve is set at 850kpa (123 psi.)
At the moment I can't see any reason why you can't go to 550 kpa.
-- Edited by iana on Thursday 17th of August 2017 02:31:27 PM
