Problem with double-check valve


  #1  
Old 09-20-04, 02:51 PM
msorelle
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Question Problem with double-check valve

Okay, here's the scenario, recently bought a house with extremely high pressure (120-160 static) and no PRV installed, the only means of backflow protection was a check valve installed inline with the first sill****, so I replaced the sill****s with self draining vaccum breaker models installed a watts model N35B PRV left it calibrated to 50 PSI and prior to that on the supply line I installed a watts model 007 double check valve. I also installed an expansion tank at the water heater to deal with thermal expansion on the house side. The problem I have is the double check valve when the system is under pressure shoots a considerable amount of water out of the test **** in the middle of the cover plate, since this is in a crawlspace I didn't let it run long to see what would happen, but it seemed excessive. Can anyone tell me if this is normal or if there is a valve stuck in the wrong position or something?

I did install a strainer before it and flushed the lines, so I'm fairly certain nothing got inside it.

Any ideas would be appreciated, in the meantime, I removed the DC valve and sweated in a piece of copper as to avoid the wrath of the wife with no water. Everything ele is fine, I increased the precharge on the expansion tank to 50 (it was 40 as shipped) to match the regulator pressure, which I confirmed with a gauge.
 
  #2  
Old 09-21-04, 10:37 PM
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Location: KY/OH
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It sounds like you are dealing with a RPBA, which is the same as a DCVA but it has a center port that dumps water to atmosphere when there is a difference in pressures between check #1 and check #2, which means it is doing EXACTLY what it was designed to do; protect from backflow/backsiphonage.


Did the city require you to install this particular model? Because usually DCVA's provide enough protection for sprinkler systems; RPBA's are designed for high-hazard type applications.

Go to www.wattsreg.com and link me a picture of exactly what you have or take a picture of your components and provide a link from www.photobucket.com



I have been a licensed backflow tester in KY for 5 years, and I have good knowledge about your situation.
 
  #3  
Old 09-22-04, 06:26 AM
msorelle
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http://www.wattsreg.com/pdf/ES-007.pdf is the spec sheet

http://www.wattsreg.com/products/ima...-res/007QT.jpg is the photo

they refer to it as a double check valve assembly and the backflow preventers I've seen in the past vent through the bottom into an air gap assembly. This is on a residence potable water supply line no sprinkler system involved. Seems like quite a bit of waste if it's going to constantly bleed the difference between the PRV and the street (in theory that will almost always be at least a 70 PSI difference)
 
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Old 09-22-04, 04:49 PM
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Okay.......now that I see what you have, that testc-ock is defective, or isn't turned completely off. The picture you have isn't a RPBA.....so that eliminates my statement above.

I always ask for proof on these because they can be easily described differently from what they actually are.


The flat blade screw should be horizontal to the testc-ock (#3) Look at the picture; all testc-ocks are shown in the off position with the flat blade slot at horizontal.



That is the only thing that is wrong........if it doesn't shut off.......then buy another testc-ock, they are fairly inexpensive.
 
  #5  
Old 09-22-04, 10:00 PM
msorelle
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Bingo, I had figured that out earlier today, the ball valve in the testc-ock was shot, it was recent purchase from a local plumbing supply house so I returned it and they happily took one look and swapped it out.

Instead of being drenched under the crawlspace, I jury rigged a hose connection to it and tested each check on the patio, much nicer way of doing it...


Many thanks for taking the time to read and respond, as I'm sure you know it sucks to be in a tight space under a house taking a bath and not know why.

p.s. for the record, I did specify the watts model # of the assembly in my original message, I know what it's like to get bad information on a problem description so I try hard not to do the same to others when I need a hand
 
  #6  
Old 09-22-04, 11:06 PM
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Sorry bout that.........I speed read postings and respond off of keywords.

I answer about 70 a night combining all the forums I belong to.......and usually answering questions when I am dead tired.


Glad to hear it worked out for ya though.


 
 

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