Water Heater Connectors Leaking

[ballvalve]

A bypass can ONLY work when one side has higher pressure than the other, so for a bypass to open, the pressure in the house has to be at or try to get above that of the supply...there isn't a pump in the PRV to push that excess water back through the PRV against the prevailing incoming water. If your pressure doesn't rise, you have something leaking.

A PRV is essentially a one-way valve. Yes, some have a bypass, but you have the thing for a reason...to keep the house water pressure at your specified, lower, safer, pressure. Without an expansion tank, that won't happen if everything else in the house is working properly. And, it is code to have one with a PRV most places.

Push on both sides with the same pressure, nothing happens.

So it seems Watts has provided an entire series of options to expansion tanks: here are a few links.

http://www.watts.com/pages/_products...ls.asp?pid=803

Here is one that really surprised me - wonder if Terry knows of it:

http://www.watts.com/pages/_products...ls.asp?pid=855

And another surprise - combo ball valve and thermal expansion relief valve for water heaters.

http://www.watts.com/pages/_products...ls.asp?pid=564

I believe all of those superior to tanks in most conditions, especially the ballvalve with the port for a drain line.

Here is a US Apollo for $50 plus: http://www.grainger.com/Grainger/APO...XZ8?Pid=search

[jadnashua]

Sounds like we need some Mfgr's information to resolve this debate.

No Mfg. would announce a thermal/ pressure bypass if it only worked at incoming pressure, because they are rated to 300 psi. So we might assume the regulator leaks a few drops....

and if incoming is 130 or 300 psi, do you think that the 2 gallon expansion tank is going to absorb the whole cities pressure? No it will just blow up. Unless the 150 psi reg on the water heater goes first.

But installing a seperate 70 psi relief inside the house backs up everything and we need not debate much more.

You need to read the REST of the statement on their specification sheet...http://media.wattswater.com/es-25aub.pdf . ..."when the pressure exceeds the supply". There is no magical means to relieve the pressure until the house side exceeds the supply, then it can bypass. Until then, it just builds up until something gives, typically the T&P on the WH, or the hoses for the washing machine, or a toilet fill valve. RTFM before you make comments, please.

[ballvalve]

RTFM? Not very polite response. I did find that later, but thats just ONE regulator out of hundreds. Some may have a acutal bypass to daylight. I will R all TFM I can find and report back, politely.

In the meantime read my links to Watts above which has created numerous products that do exactly what my post originally proposed, lose the tank and use a relief valve inside the house. Little did I know how many versions existed.

[jadnashua]

I doubt you will find any PRV that has the magical means to maintain the set reduced pressure, bypass or not, with thermal expansion. One with a bypass will allow the house pressure to rise until it reaches the supply, then bypass. The physics just don't allow it. To maintain the pre-set pressure, you'd need to bleed the volume off, and I've never seen a PRV with a drain line (I suppose one could exist, but why?).

[ballvalve]

Well, the "why" would be to eliminate the so called expansion tank, and provide near set point pressure protection on the feed side.

This all started because someone told the guy to get a expansion tank to solve a run-away pressure reducing valve failure.

That was very bad advice. I would venture a guess that a 2 gallon bladder tank can accept only a few quarts of liquid if that. He would still have high pressure and likely a broken bladder in the little expansion tank.

If his PRV was set at 60 psi for 20 years without incident, perhaps at times he had internal pressures of 80 psi, which was expended in a moment when a valve of any type in the house was opened.

Therefore, IF no one makes a PRV with a relief valve that automatically vents to set pressure [I am fairly sure they are out there]
then set your PRV to 60 PSI and use a 65 or 70 or 80 psi standard relief valve or one of the other interesting products in my links that allow you to drain the droplets to a bucket or drain or toilet tank.

It must be apparent that a back-up to the water heater T&P valve, and the displacement of a rubber bag in a tin can is a superior solution.

And by the way, how do the manufacturers get away with saying their regulators are equipped with a "thermal and pressure bypass" ? A pressure bypass would be logically interpeted to mean a safety feature that will not allow downside pressure to ever reach feed pressure. Many are rated for 400 psi feed, so it would be absurd to "bypass" at 400 psi. It is a nonsensical term, and even a dangerous one.

They offer many back-up devices, shown in the links, so they must be aware of the issue.

Sure looks superior to the bag in a box deal: http://www.watts.com/pages/_products...ls.asp?pid=564

[jadnashua]

Typical expansion is only in the area of maybe a cup when the WH runs. But, since ANY expansion increases pressure until something gives (water isn't compressable!) something has to be stressed and maybe broken when that expansion occurs. Expansion tanks last for years without problems. They're inexpensive and easy to replace. If you've ever had the town flush the lines (by opening fire hydrants, typically) and seen the water clarity for awhile after, anything you'd get from food-grade rubber in an expansion tank is nothing. Nor is a little rust. When it fails, you replace it. Simple, clean, reliable. Nothing in this life is forever, you repair or replace when it fails. The key is being on top of it.

[ballvalve]

Unfortunately, the only thing the average homeowner or renter is on top of is his sofa or barcalounger. Or his girlfriend.

Expansion tanks maintenance is about on the chart of fun near colonoscopy or root canals. At least a root canal tells you when its time to be looked at.

I'll venture a guess that 50% plus of tanks are blown out, and the systems keep working anyway.

[jadnashua]

I'll take that bet. The T&P will release and it may only be a half-cup to a cup, but it WILL come out unless something weak balloons up to allow the water to expand and maintain the pressure below the T&P valve, or the bypass (if it exists in the PRV) is working AND the supply pressure is below the T&P release point. In any case, the pressure WILL rise, and you are trying to prevent that by putting in a PRV in the first place.