COCJ
Well-known member
I just bought an adjustable water pressure regulator. What is the maximum safe water pressure? What is the ideal pressure. We have a small Jayco Class C.
Water Pressure Regulator
- Thread starter COCJ
- Start date
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If you have answers, please help by responding to the unanswered posts.
NY_Dutch
Well-known member
60 PSI would be the maximum setting I'd suggest. Remember of course, a pressure regulator cannot increase the pressure above the source pressure.
Isaac-1
Well-known member
60 psi is the modern RV standard for the last decade, though in theory industry standards call for 150 psi testing of water systems. 45 psi was the standard for a long time, and you will still see this figure mentioned.
Mark_K5LXP
Well-known member
From a practical standpoint there's no reason to have more than about 45PSI in an RV. Even if the system can support more, it will just promote going through more water which unless you're 100% city supplied, you don't want to run through more than necessary from the tank. Yes, you can meter the flow with valves but at least in my case with pressure set to a nominal 45 I don't have to make critical adjustment just to wash my hands or take a shower.
Mark B.
Albuquerque, NM
Mark B.
Albuquerque, NM
Kirk
Well-known member
Since the question is the maximum pressure that it is safe to set the adjustable regulator, the answer is really more opinion that fact. If we assume that the RV is in like new condition and was built since the industry adopted PEX plumbing, you should be safe to set it to 100# as long as you keep everything in your RV at like new conditions. On the other hand if your RV is getting a bit long in the tooth, that might not be a safe pressure.
A much better discussion would be what is the best or ideal pressure setting that should be used on an adjustable water pressure regulator for an RV. Major plumbing supply companies sell adjustable water pressure regulators for stick houses and those always come set between 40# and 70# of pressure. When I lived in WY I found that I was constantly dealing with faucets dripping and often the valve seats were eaten so that the faucet set needed to be replaced. A neighbor who was a plumber told me that the problem was that our city water pressure was too high and usually ranged from 90 pis to as much as 100 psi and that was destroying our faucets. He helped me to install a pressure regulator and at his suggestion we set it to 60 psi. No more problems and the showers seemed to have no noticeable change. My point is that if you consider the water pressure that arrives at the faucet, there is never a need to exceed 45 psi but the problem with most RV water pressure is not the supply pressuer but the volume of water that you can get at that pressure. RVs today use either 3/8" or 1/2" PEX water lines and if you supply water into the system at 60 psi and then measure the pressure to the shower with only it using water it will easily exceed 45 psi but if you also have several other things using water at the same time you will be lucky to see 30 psi.
It used to be that all of the cheaper, nonadjustable RV water pressure regulators had no more than a 1/4" water passage and some were smaller. Today if you are careful you can find them with as much as 3/4". Most adjustable regulators have between 3/4" and 1" passages so that the pressure is maintained to the inlet of the RV at all possible volumes of use. That is what is most important. It is also important to understand that the static pressuer inside of your water system is at the highest when no water is being used. In addition, if you do not have an accumulator installed in the water system, the heating of water in the water heater tank can increase that internal pressure by 10-20 psi. If you have a check valve on the hot water outlet side of the water heater and an accumulator on the inlet side you should be just fine with a supply pressure of 60 psi. Unless you have changed the set point, your RV fresh water pump most likely shuts off at between 45 & 55 psi.
A much better discussion would be what is the best or ideal pressure setting that should be used on an adjustable water pressure regulator for an RV. Major plumbing supply companies sell adjustable water pressure regulators for stick houses and those always come set between 40# and 70# of pressure. When I lived in WY I found that I was constantly dealing with faucets dripping and often the valve seats were eaten so that the faucet set needed to be replaced. A neighbor who was a plumber told me that the problem was that our city water pressure was too high and usually ranged from 90 pis to as much as 100 psi and that was destroying our faucets. He helped me to install a pressure regulator and at his suggestion we set it to 60 psi. No more problems and the showers seemed to have no noticeable change. My point is that if you consider the water pressure that arrives at the faucet, there is never a need to exceed 45 psi but the problem with most RV water pressure is not the supply pressuer but the volume of water that you can get at that pressure. RVs today use either 3/8" or 1/2" PEX water lines and if you supply water into the system at 60 psi and then measure the pressure to the shower with only it using water it will easily exceed 45 psi but if you also have several other things using water at the same time you will be lucky to see 30 psi.
It used to be that all of the cheaper, nonadjustable RV water pressure regulators had no more than a 1/4" water passage and some were smaller. Today if you are careful you can find them with as much as 3/4". Most adjustable regulators have between 3/4" and 1" passages so that the pressure is maintained to the inlet of the RV at all possible volumes of use. That is what is most important. It is also important to understand that the static pressuer inside of your water system is at the highest when no water is being used. In addition, if you do not have an accumulator installed in the water system, the heating of water in the water heater tank can increase that internal pressure by 10-20 psi. If you have a check valve on the hot water outlet side of the water heater and an accumulator on the inlet side you should be just fine with a supply pressure of 60 psi. Unless you have changed the set point, your RV fresh water pump most likely shuts off at between 45 & 55 psi.
Gary RV_Wizard
Site Team
The onboard water pump would have been factory-set to 45 psi but the water system is tested to a much higher pressure, usually around 100 psi for RVs built in the last two decades. Most RVers who have regulators set them between 50 & 60 psi. If that pressure isn't adequate, you have a water flow restriction problem and more pressure isn't going to help noticeably. The most common problem attributed to "low water pressure" at the shower head and that is actually low flow (low gallons/minute) due to restrictions in the plumbing. Possibly in the regulator itself but also often found in an inline filter, shower head, or faucet.
