Ballcock with pressure relief built in - Page 6 - Plumbing Zone

TheMaster · 02-07-2010, 05:18 PM

Quote:

Originally Posted by Colgar

From the same book:

Water confined in a storage tank or piping system will, when subjected to a temperature rise of 10 degrees, increases pressure from 50 lbs to 250 lbs.

That doesn't really answer your question and raises some of my own.

Where do "they" get the 50 lbs from?

Does that mean a 10 degree rise results in 5X more pressure or 200lbs more pressure?

Maybe they meant 100 degree temp rise........Theya re getting the 50psi from the starting pressure...say the citys pressure was 50 psi.
Considering 10 degrees isn't shiot,I think their numbers are off on that,BUT I have seen it 1st hand and the pressure will go really high...pegged my gauges. Its no joke

Colgar · 02-07-2010, 05:21 PM

The ten degree rise is backed up by a chart.

Whether it's correct or not......

TheMaster · 02-07-2010, 05:25 PM

Quote:

Originally Posted by Colgar

The ten degree rise is backed up by a chart.

Whether it's correct or not......

I figured that part out...I think they are correct but you dont see that kinda pressure in the water heater because the tank swells up. Thats why I no scientist....or a physics major

Their numbers are not allowing for the container to swell AT ALL

TheMaster · 02-07-2010, 05:33 PM

Any of you guys notice the vertical seam on the water heater sheetmetal jacket ever seperated? Thats a sign of an over pressured tank and so is the bungs in the top poiting away from each other. If it goes high enough the tank bottom will invert also.

Colgar · 02-07-2010, 05:33 PM

Quote:

Originally Posted by TheMaster

I figured that part out...I think they are correct but you dont see that kinda pressure in the water heater because the tank swells up. Thats why I no scientist....or a physics major

Their numbers are not allowing for the container to swell AT ALL

Yeah, i don't think you would ever see that either- with out stars and planets aligning and something going drastically wrong.

I remember closing some valves on a water heater piped in a parallel configuration and I forgot to kill the burner. relief was dribbling in less than a minute.

Either way you shake it, water is an azz kicker. We think we control it, but it controls us.

TheMaster · 02-07-2010, 05:49 PM

Quote:

Originally Posted by Colgar

Yeah, i don't think you would ever see that either- with out stars and planets aligning and something going drastically wrong.

I remember closing some valves on a water heater piped in a parallel configuration and I forgot to kill the burner. relief was dribbling in less than a minute.

Either way you shake it, water is an azz kicker. We think we control it, but it controls us.

Exactly!!!! And your just guessing the relief valve opened at 150...who knows it could have been way higher. Not that you should have known,just sayin nobody really knows that day what the pressure went to.

gusty60 · 02-07-2010, 06:39 PM

Quote:

Originally Posted by Redwood

I think your data is a tad bit skewed...

I'm just saying...

A relief valve in a ballcock isn't the brightest idea ever hatched...
It is to easily circumvented by replacing a ballcock with one that doesn't have that feature...

Or homey gets tired of hearing dribbling ballcock and shuts off angle stop in the middle of the night.

Protech · 02-07-2010, 10:05 PM

Depends on the volume of the water being heated and the type of piping used. Just saying "10 degrees of rise" without the other variables of the equation tells you nothing.

Quote:

Originally Posted by Colgar

From the same book:

Water confined in a storage tank or piping system will, when subjected to a temperature rise of 10 degrees, increases pressure from 50 lbs to 250 lbs.

That doesn't really answer your question and raises some of my own.

Where do "they" get the 50 lbs from?

Does that mean a 10 degree rise results in 5X more pressure or 200lbs more pressure?

Alan · 02-08-2010, 01:44 AM

Quote:

Originally Posted by Redwood

I'm wondering if any of you have ever run across one of these...

http://www.watts.com/pdf/S-GOV80.pdf

They are a ballcock that has an 80-psi relief valve installed and are marketed as a solution for thermal expansion in a closed system.

I've never seen one until the other day when I was at the Watts website getting some info links for a thermal expansion discussion here. It looks like a case where if you did run across one of these changing a ballcock that wasn't leaking could upset the apple cart and start a T&P discharging.

I can't say that I'm a fan of using pressure relief to control thermal expansions effects and I would naturally lean towards installing a tank but, I just wanted to give everyone a heads up on this product...

We use them often, when a contractor will insist on installing one of them short water heaters underneath the tightest area unused under the stairs, and no room for a tank.

I don't like them mainly because they deteriorate awfully quickly, especially when customers use them bleach tablets.

They do however sell rebuild kits for them if you come across one and need it. It has all new gaskets for the device. Not sure on the cost comparison between that and a tank, but the install will be cheaper i'm sure.

Alan · 02-08-2010, 01:47 AM

Quote:

Originally Posted by TheMaster

Any of you guys notice the vertical seam on the water heater sheetmetal jacket ever seperated? Thats a sign of an over pressured tank and so is the bungs in the top poiting away from each other. If it goes high enough the tank bottom will invert also.

Every A.O. w/h we buy has bungs pointing away from each other. That's got to be just cheap factory work then, eh? Bungs? lol, we call them nipples 'round these parts.

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02-07-2010, 05:21 PM	#52
Colgar Senior Member Join Date: Jul 2009 Location: Peo, IL Posts: 1,153 My Photos	The ten degree rise is backed up by a chart. Whether it's correct or not......

02-07-2010, 05:33 PM	#54
TheMaster Registered Member Join Date: Jun 2009 Posts: 6,437 My Photos	Any of you guys notice the vertical seam on the water heater sheetmetal jacket ever seperated? Thats a sign of an over pressured tank and so is the bungs in the top poiting away from each other. If it goes high enough the tank bottom will invert also.