Pressure regulator interferes with backflow preventer

[Andy]

We've been having a problem with our water pressure regulator interfering with the hose bibb vacuum breaker backflow preventers that are installed on the water faucets of every campground we visit. We connect the pressure regulator to the hose bibb vacuum breaker so our hose is protected from high water pressure. However this creates back pressure on the vacuum breaker, causing the valve in the vacuum breaker to close, which cuts off the flow of the water to our RV. What can we do to fix this situation, which seems like it would be a very common problem?

[docj]

Since most of us have pressure regulators that don't cause this problem, my first question is what kind of regulator are you using?  If it is one of those very inexpensive "regulators" that are really just flow restrictors I imagine that the flow rate is low enough that the backflow preventer doesn't "sense" that water is flowing.  If it is a "real regulator" and you are having this problem then I would suggest replacing it.

[Dutch_12078]

I suspect a faulty vacuum breaker is the problem. The pressure regulator, no matter what kind it is, is not capable of creating more back pressure than is normally created by simply not running any water in the RV. As far as the low cost regulators go, I've never seen one that didn't have at least a basic spring loaded valve inside that does limit the maximum pressure allowed. The diameter of the valve determines the maximum flow rate, but the spring valve limits the pressure even when water is not flowing. A flow restriction alone will not do that, allowing full line pressure with no flow.

[Devilishjim]

try taking your regulator out of line and if water flows throw your regulator away if it doesnt then check your backflow valve at the RV it is probably broken thus going into closed position preventing flow...been there done that

[Dutch_12078]

Hmmm, on reread, I missed that this happens in more than one location. That does make your regulator the primary suspect as said.

[Devilishjim]

The backflow valves in RV are plastic and a sudden surge of water after air in hose will break the plastic and lil tab that holds spring, which kind of leaves the round disc for flow prevention just sorta floating around in its own lil circle sometimes allowing water to flow and other times shutting it off completely

[Devilishjim]

After rethinking take the hose off RV and turn on the water and see if you get good flow from hose if yes then hook back to RV and if nothing then remove hose from inside rv at your water hookup and pull the guts out of that valve, BUT if you do that the next time you turn 12V pump on the water will come out of that fitting because you removed your backflow

[Kirk W]

Andy, welcome to the Escapee forums! Since this happens everywhere you go but has not been experienced by anyone here, there must be something unique to your arrangement. I am wondering what pressure regulator you are using? I have used several different types of pressure regulators and I don't recall ever having it cause that problem. With the adjustable regulator, I always use a short connecting hose between the bib and the regulator, but I can't see why that would matter. Might there be some problem with the pressure regulator that you are using? 

[SWharton]

I don't think you need to worry about your hose blowing. Should be rated for about 150+lbs. If not, you might want to get a hose etc. from RVwaterfilterstore.com. He has quality products and knows his business.

[57becky]

I suspect your pressure regulator has one of those cone shaped screen washers in the female end, and if so, that screen will put pressure on the little rod that sticks out of the backflow preventer.  I had that problem and now use a short hose between the hose bib and the regulator.

[Andy]

Thank you everyone for your great replies!! The PR we inherited with our 2003 Holiday Rambler Imperial is a Marshall Brass one, which they now call part number ME9240. It doesn't have a screen in it that would interfere with the little plastic rod in the BP. With the PR not involved the water system flows just fine, just at too high of pressure if the park pressure is too high. So as several have said, since others aren't having this problem all signs point to there being a problem with the PR. We were planning to replace this anyway, as the one we have isn't lead-free, and the Valterra A01-1122VP looks impressive since it's lead-free, is set at 50-55 PSI (which seems better than the usual 40-50 PSI, which is lower than necessary, possibly affecting shower performance), and offers 15-20% greater flow rate. We plan to pick up one of the Valterras at CW in Fort Myers when we drive right past it today! Thanks again for the many helpful replies!!

[billr]

If your buying a new one anyway contact rvwaterfilterstore he has Watts regulators that are adjustable and quality units. Can get with the gauge out and addition gauge in. Nice to see info. 

Have used them for years. Hoses too. 

He has them at reasonable prices. 

Will outlast anything CW sells. 

[Andy]

Thanks again for the help!! I don't understand what the benefit of an adjustable PR is in this application. And the cheapest Watts PR on RVWaterFilterStore costs $110+, while the Valterra at CW costs $13. I could replace the Valterra 8 times over. I have a separate pressure gauge that I can use with a wye to get pressure readings. I don't mean to be rejecting advice by this, the advice is very much appreciated! I just don't understand the advantage of the more expensive adjustable PR is in this application. Thanks again!!!

[Kirk W]

26 minutes ago, Andy said:

while the Valterra at CW costs $13.

While that is true, those also restrict the flow volume and you may not be happy with the result. Be sure that you verify the volume capacity of the regulator as those cheap ones usually do not have enough volume capacity. 

[Andy]

Again, thanks for the help!! I just looked at Amazon for reviews of the Valterra A01-1122VP, and there's 413 reviews, 75% of which are 5 stars, and 14% of which are 4 stars. Even if lots of these are Astro Turf, it still seems to be a well-reviewed PR, worth trying at the price, it seems to me. Thanks again!!

[DesertMiner]

Good luck with your choice.  Price doesn’t always equate to the best product for the application.

[Twotoes]

Valterra also makes an adjustable regulator selling for about $75 which is much better than the preset model selling for less.  I purchased one of the Watts adjustable regulators from RVwaterfilterstore.com for $100 and it has never worked. Also very very very poor customer service from Rick at  rvwaterfilterstore.com. Sent the Watts back for warranty repair and had to pay shipping. When he sent it back to me I had to give him my credit card to pay for the return shipping. It still didn’t work. Shipped it back to him again on my dime and he charged me shipping to return it to me again. Not so good on a warranty repair. And it still doesn’t work. Have never used it. It sits in a box in my storage. Cost me almost in shipping as the regulator. I will NEVER do business again with him. 

[Kirk W]

If you look on Amazon Marketplace you will see that they have quite a list of adjustable, lead-free regulators for less than $50. But in looking at them, none give the water passage diameter of maximum flow rate, which is key to a good water supply.

[Tex Bigfoot]

On ‎2‎/‎3‎/‎2018 at 1:26 PM, 57becky said:

I suspect your pressure regulator has one of those cone shaped screen washers in the female end, and if so, that screen will put pressure on the little rod that sticks out of the backflow preventer.  I had that problem and now use a short hose between the hose bib and the regulator.

Andy 

before you put money into a new regulator even though I agree with getting a good adjustable one .

I believe that 57 Becky has nailed the problem .

take that screen / washer out and turn it over then try everything again.

or even take your finger and mash the screen flat. 

[Andy]

Tex Bigfoot,

Thanks for your help! The Marshall Brass PR doesn't have one of those screens in it, but if it did I expect it would cause the interference you describe. However we now bought one of the Valterra A01-1122VP regulators, and it does have one of those screens in it. When I first use this new PR I plan to check for that interference, and do just what you recommend, either turn the screen over, or push it in so it doesn't hit that little plastic rod in the BP. BTW, I emailed Valterra about this PR/BP interference problem, and they said they've never heard of it!

Thanks again! Andy