Ended up with very low water flow off the town supply, so decided to have a look at the pressure limiting valve. Unscrewed the housing, which is all I could do in a camping situation and examined the unit. Clean, nearly as clean as off the production line, so what could I do, I've heard about stretching the spring, so that's what I did, a bit of "O" ring grease and refitted. Yes water flow improved.
What intriges me, is that this is a common problem, replace the valve they say at the suppliers etc., but surely the item is not performing as required. What is the problem? the only thing I can think of is that the unit is not designed to have pressure coming from the reverse direction, i.e. the in house 12v pump in operation, this may compress the spring. I haven't been able to find a sectioned drawing of the valve, but if this is what is causing the problem, there must be thousands of vans fitted with a valve that won't perform as it should.
This unit has a built in NRV, perhaps the solution is to buy one that does not have the built in NRV, and fit a separate NRV upstream so the pressure limiting valve is not subjected to this back pressure. Of course I am only guessing that this may be the cause of the problem.
And yes I have heard about the fitting of an up-stream NRV, but I think the system has enough flow restriction as it is, including the pipe work being under size, i.e. 12mm OD instead of 12mm ID, read the installation instructions of the pump.
On our secondhand 2012 Concept the first time we hooked up to towns water supply and went to have my shower, it was some what disappointed when there was no real water pressure.
Getting redressed and trying to solve the problem took sometime, the pressure reducing valve at first was working after I disconnected nylon hose from upstreams towards the next junction which was a plastic NRV, so I then connected it back up still no pressure inside the caravan. Well I blamed the NRV, pull it out run a drill down it, replaced it and we had water pressure until the wife went for shower, all hell breaks loose. What in the ,,,,,,, goes on.
For next 2 weeks we only use the water from our tanks via our pump until while travelling water starts to dribble out the town hook up point. So now I need a new NRV as I had drillled the old plastic one, lucky we were up near Armidale when things come to a head. After spending some money problem solved.
The pressure limiting valve must of been hit with a rock causing it to jam. The barrel of the valve had very small dent about half way long, what a pain.
I now use a $10 PLV from a agri shop on my hose when connected to town water supply and a brass NRV to keep it all under control.
