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perryg114 · 03-11-2013, 10:51 AM

Many of us have older trailers with a mishmash of jury rigged tubing with various combinations of copper and plastic (PB) tubing. I don't like subjecting the old PB tubing in my trailer to over 40 psi. For the first time since I bought the trailer (1.5 yrs) I hooked it to a water hose at home. I first put a water pressure gage after the existing regulator. I turned on water and the gage that maxed at 50psi ran all the way to the peg. So I backed off on the regulator and the flow got less but as soon as you turned the water off the pressure would creep back up to the supply pressure.

So I went to Lowe's and bought a brand new pressure regulator with the adjusment. This one would at least attempt to regulate the pressure but when you stopped the water flow it would creep back up to the supply pressure over a few minutes. I am not sure if mine is defective or if they all are like this.

The inline ones like you get from the camping store are little more than flow regulators which does nothing to keep you from overpressurizing your plumbing system in your trailer.

My advice is that you test anything you put on your trailer with a gage after the regulator. I bet most of the ones you have installed now don't work like they are supposed to.

I am going to leave the new regulator installed and see if it seats in over time but I think it will probably go back to Lowe's. These things are made just like a gas pressure regulator and they should work if built properly.

I have been running off the fresh water tank but it gets musty smelling and cleaning it out everytime we go camping is something I would rather not have to deal with.

Perry

Inland RV Center, In · 03-11-2013, 10:59 AM

Quote:

Originally Posted by perryg114

Many of us have older trailers with a mishmash of jury rigged tubing with various combinations of copper and plastic (PB) tubing. I don't like subjecting the old PB tubing in my trailer to over 40 psi. For the first time since I bought the trailer (1.5 yrs) I hooked it to a water hose at home. I first put a water pressure gage after the existing regulator. I turned on water and the gage that maxed at 50psi ran all the way to the peg. So I backed off on the regulator and the flow got less but as soon as you turned the water off the pressure would creep back up to the supply pressure.

So I went to Lowe's and bought a brand new pressure regulator with the adjusment. This one would at least attempt to regulate the pressure but when you stopped the water flow it would creep back up to the supply pressure over a few minutes. I am not sure if mine is defective or if they all are like this.

The inline ones like you get from the camping store are little more than flow regulators which does nothing to keep you from overpressurizing your plumbing system in your trailer.

My advice is that you test anything you put on your trailer with a gage after the regulator. I bet most of the ones you have installed now don't work like they are supposed to.

I am going to leave the new regulator installed and see if it seats in over time but I think it will probably go back to Lowe's. These things are made just like a gas pressure regulator and they should work if built properly.

I have been running off the fresh water tank but it gets musty smelling and cleaning it out everytime we go camping is something I would rather not have to deal with.

Perry

Perry.

It sounds like someone has super modified the plumbing system.

The water pressure regulator that Airstream has used for many years, works perfectly.

Andy

perryg114 · 03-11-2013, 04:01 PM

I don't know if the one I that was in there was factory or not . I think it was made by Watt? The new one is made by the same company.

Perry

Inland RV Center, In · 03-11-2013, 04:17 PM

Quote:

Originally Posted by perryg114

I don't know if the one I that was in there was factory or not . I think it was made by Watt? The new one is made by the same company.

Perry

That's the brand Airstream has used for over 50 years.

Andy

Protagonist · 03-11-2013, 04:59 PM

Quote:

Originally Posted by perryg114

So I went to Lowe's and bought a brand new pressure regulator with the adjustment. This one would at least attempt to regulate the pressure but when you stopped the water flow it would creep back up to the supply pressure over a few minutes. I am not sure if mine is defective or if they all are like this.

They are all like that. A pressure regulator only works when there's actual flow. Shut off the flow downstream of the regulator, and the pressure will build up to the same pressure as at the source. The more the pressure regulator chokes off the flow, the longer it will take for the pressure to build back up, but it will happen.

I won't bore you with a physics lesson in fluid dynamics to explain why it works that way. Count your blessings; I can bore a stone to tears by talking to it!

sandhill3000 · 03-11-2013, 05:06 PM

Inland RV Center -
Are you saying that Airstreams come with a water regulator already in the water system or they are just available?

perryg114 · 03-11-2013, 06:08 PM

Not true, a pressure regulator regulates pressure. We use them all the time at NASA for regulating pressure of gases. If the pressure gets too high because the regulator fails, there are Relief Valves that blow to protect anything down stream. There are also relief valves on air compressors so if the compressor does not shut off, you won't have an explosion. The seat is bad on poorly designed on the new regulator that I installed. A regulator that does not regulate pressure is dangerous and fradulent. You have to have a regulator to take a 2000lb K-bottle of He, N2, H2, Air etc. down to a working pressure say 100psi. We are required to install relief valves down stream of any regulators in case they fail and I have never seen one fail but that is what we are held to. I can install a relief valve that will blow and send water out a vent line to protect the trailer. What do you think that a blow off valve is on your water heater? It is a pressure regulator or in this case a relief valve. If the pressure gets too high it blows. If it is bad it would leak like the crappy water pressure regulator that I have does.

Perry

markdoane · 03-11-2013, 06:51 PM

If you have a Watts regulator, it should not creep up when you shut off the water flow. Unless it is bad/defective. Or unless you forgot to turn of the water heater and the increase in pressure is due to thermal expansion. Some (not all) direct acting regulators have a thermal expansion bypass to correct this.

murreywalker · 03-11-2013, 06:57 PM

Quote:

Originally Posted by sandhill3000

Inland RV Center -
Are you saying that Airstreams come with a water regulator already in the water system or they are just available?

I'm not Andy, but the answer to your question is yes, they all have a built in water pressure regulator.

sandhill3000 · 03-11-2013, 08:49 PM

Then why did I just buy one?

Don't answer that!

Protagonist · 03-12-2013, 04:58 AM

Quote:

Originally Posted by perryg114

Not true, a pressure regulator regulates pressure. We use them all the time at NASA for regulating pressure of gases. If the pressure gets too high because the regulator fails, there are Relief Valves that blow to protect anything down stream. There are also relief valves on air compressors so if the compressor does not shut off, you won't have an explosion. The seat is bad on poorly designed on the new regulator that I installed. A regulator that does not regulate pressure is dangerous and fradulent. You have to have a regulator to take a 2000lb K-bottle of He, N2, H2, Air etc. down to a working pressure say 100psi. We are required to install relief valves down stream of any regulators in case they fail and I have never seen one fail but that is what we are held to. I can install a relief valve that will blow and send water out a vent line to protect the trailer. What do you think that a blow off valve is on your water heater? It is a pressure regulator or in this case a relief valve. If the pressure gets too high it blows. If it is bad it would leak like the crappy water pressure regulator that I have does.

Perry

I yield to your superior knowledge. Note to self: Never again joke about rocket science!

dznf0g · 03-12-2013, 07:16 AM

Quote:

Originally Posted by sandhill3000

Then why did I just buy one?

Don't answer that!

Well I'll tell you why I did. The plastic AS (forget the brand...Surflo or Thetford....?) regulators are notorious leakers. I have pulled mine out, cleand and resealed once, and I really don't want it to be a regular maintenance thing. Next time it leaks, I may pull it out of the system and permanently mount my Watts/ with gauge into the system.

perryg114 · 03-12-2013, 07:32 AM

Well I guess I will take mine back and get another one. I would still want one even if I had everything PEX. At least I have a gage now so I can see what the supply pressure is.

In your house toilet flush valves are usually the first things to go bad from excess pressure.

Perry

tkowalyk · 03-12-2013, 08:57 AM

Quote:

Originally Posted by perryg114

Well I guess I will take mine back and get another one. I would still want one even if I had everything PEX. At least I have a gage now so I can see what the supply pressure is.

In your house toilet flush valves are usually the first things to go bad from excess pressure.

Perry

I know that the AS has a built in regulator. I guess I am a bit old school -- it might be belts and suspenders, but I use an external regulator with a gauge set at 50PSI. This seams to provide enough water for a shower, and the flow is adequate at the sink and toilet.

DMT · 03-12-2013, 09:12 AM

I'd have to agree with Protagonist and Sandhill as you are both right. It depends on the design of the device. Some are designed to operate in flowing conditions only. A different design is required to provide pressure control in flowing and static states. I have a long history with this in the O&G industry. It may not be apparent in looking at the valve, but the latter is likely more expensive.

Don

perryg114 · 03-12-2013, 10:11 AM

Static pressure is what leads to stress related failures of plumbing systems especially modern plastic systems. A regulator that only works under flow is useless. There are such things as flow restrictors that limit flow for water conservation purposes. Every modern shower head has a flow restrictor.

Perry

perryg114 · 05-08-2013, 06:26 AM

Ok I just called Watts the manufacturer of my new water pressure regulator and they said that the pressure should not creep up to the supply pressure when there is no flow. This behavior is not normal or desired.

Perry

perryg114 · 05-12-2013, 10:28 AM

Sucess finally, I went to Lowe's and returned my $30 Watts water pressure regulator and bought the $70 all metal one and the new one works like it should. As soon as I turned on the water the pressure went to 50 psi and stayed there. I lowered it to 40psi and it is holding steady. It seems that nothing is easy.

Perry

dkottum · 05-12-2013, 11:18 AM

Regardless of what you regulate the input pressure to, the campground anti-reverse valve, or your water pump system, will lock the water in your trailer plumbing, which will then build up additional pressure by thermal expansion, especially the water heater.

There is meant to be some air space in the water heater to take up some of this pressure increase, but it's not always enough. Some of us have added water pressure accumulators to help.

doug k

perryg114 · 05-12-2013, 11:28 AM

You can add an accumulator or a relief valve that will blow at anything over 50psi. You would need a waste dump line to do this so the water has some place to go. Both would be even better. I don't even have the water heater on so my regulator problems were not due to that. You are going to waste a little water with a relief valve but it is better than a flooded trailer.

Perry