Mains Pressure Reducing Valve operation

We moved into a house built in 2020 and have been somewhat underwhelmed by the household water pressure. I recently bought a water pressure meter from Bunnings and have been surprised by the readings.

I measured the pressure at the first tap in our house as 310kPa. The first tap in our neighbour's property measured 510kPa. Our water meters are side by side at the property boundary, same distance to the front taps.


This appears to be the PRV installed in our home https://www.wattsau.com.au/products/plumbing-flow-control-solutions/pressure-reducing-valves/prvb-500#jl_cd06c94a-fea9-481c-81eb-68d589135760


As far as I can see the pressure reducing valve is supposed to limit the household side pressure to 500kPa, so I would have expected to see 500kPa also measured in my house while the street pressure is above 500kPa. However it is not.


Reading the PRV description it says "Set pressure is 500kPa, at 1600kPa inlet pressure". Is it to be expected the house side pressure of 500kPa would only be realized if the inlet pressure is actually at 1600kPa? At lower inlet pressures should lower house pressures be expected?


What PRV would not reduce internal house pressure unless the inlet pressure actually goes above 500kPa? The street pressure does vary, another near neighbour had a leak recently and the plumber measured their street pressure as 610kPa while repairing at the time.

could also be something else reducing the pressure.
eg. in my place (purchased a couple of years ago) the water pressure got worse and worse in the house while the garden taps were amazing pressure.
turns out the previous owner had installed one of those domestic filtration units in the yard (and long overgrown by bush) that had gradually got clogged with sediment etc.
easy removal, once found.
the only absolution I can give is that they were trying to protect water devices such as the Solar HWS.
there was double filtration under the sink as well, so that was triple filtered.

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Originally Posted by Fuzzie

We moved into a house built in 2020 and have been somewhat underwhelmed by the household water pressure. I recently bought a water pressure meter from Bunnings and have been surprised by the readings.

I measured the pressure at the first tap in our house as 310kPa. The first tap in our neighbour's property measured 510kPa. Our water meters are side by side at the property boundary, same distance to the front taps.


This appears to be the PRV installed in our home https://www.wattsau.com.au/products/plumbing-flow-control-solutions/pressure-reducing-valves/prvb-500#jl_cd06c94a-fea9-481c-81eb-68d589135760


As far as I can see the pressure reducing valve is supposed to limit the household side pressure to 500kPa, so I would have expected to see 500kPa also measured in my house while the street pressure is above 500kPa. However it is not.


Reading the PRV description it says "Set pressure is 500kPa, at 1600kPa inlet pressure". Is it to be expected the house side pressure of 500kPa would only be realized if the inlet pressure is actually at 1600kPa? At lower inlet pressures should lower house pressures be expected?


What PRV would not reduce internal house pressure unless the inlet pressure actually goes above 500kPa? The street pressure does vary, another near neighbour had a leak recently and the plumber measured their street pressure as 610kPa while repairing at the time.

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The valve may be partially blocked/faulty and not working as it should so personally I would replace the valve because that is what a plumber would do.
Generally they cost around $60 depending on if you use the same brand.
Then test again.

Mate of mine was getting no water at all so I removed the plv and left it out.

Be aware pressure and flow are 2 totally different things.

Although the description for my PRV says it is factory set at 500kPa and with no indication it is field adjustable, I got up the courage to take off the external cap which in turn exposed a slightly corroded adjustment screw. It appeared to be backed all the way out. I screwed it in as far as it seemed to want to go and my house side pressure has gone up to 400kPa. I suspect the unit really does need replacement but 400kPa internal is a whole lot better than 300kPa anyway.