I think I may have solved the mistery.... - Plumbing Zone

Protech · 06-15-2010, 03:50 PM

Back in mid-2009 dunbar plumbing (known as roast duck at that time) posted some pics of a water heater with out of plumb heater connections at the top. I believe the cause of the failure was water hammer.

Read here: http://www.hotwater.com/bulletin/bulletin11.pdf

Protech · 06-15-2010, 03:52 PM

"Water hammer is the destructive forces, pounding noises and vibration in a piping

system when water flowing through a pipeline is stopped abruptly. When water
hammer occurs, a high intensity pressure wave travels back through the piping
system until it reaches a point of some relief. The shock wave will then surge back
and forth between the point of relief and the point of stoppage until the destructive
energy is dissipated in the piping system. The violent action accounts for “banging”,
“thumping”, and/or intense vibration in the pipe line. Although noise is generally
associated with the occurrence of water hammer, it can occur without audible sound
or noise. Quick closure always causes some degree of shock with or without noise.
The common cause of water hammer is single lever faucets (sinks/lavatories) or
automatic solenoid valves (dishwashers, washing machines, etc.). The speed of the

valve closure time is directly related to the intensity of the surge pressure."

"The damage from water hammer can manifest itself in a number of ways. The most

common are:

·

Expanded Tank Shell - This can be demonstrated by measuring the circumference at
various locations along the shell. Pressures in excess of the maximum design working
pressure can cause permanent deformation of the shell.

·

Collapsed Flue Tube - This will choke off the ability to vent the products of combustion
causing the flame and/or combustion to spill out from the combustion chamber. Often
this will occur where thinning of the flue tube walls has occurred due to contamination
of the combustion air or because of excessive condensation.

·

Inverted or Deformed Tank Heads - Often this accompanies collapsed flues, but one

or both heads can be deformed."

PLUMBER_BILL · 06-15-2010, 05:20 PM

[quote=Protech;120658]"Water hammer is the destructive forces, pounding noises and vibration in a piping

system when water flowing through a pipeline is stopped abruptly. <snip>

All new homes we have done for the past 13-14 years have had thermal expansion tanks installed as all new houses have backflow valves. Not RPZ or testable double checks. The muncipal authorities install Watts # 7's Now the placement of the tanks was where the water came in on the house side of the meter. This did two things, took care of the thermal expansion, but also gave each house a shock absorber. Now older homes are getting a meter changeover with backflow. We have an inspector here [yep there charging a $54.00 permit fee to install a tank] that won't allow a tank to be installed if there is a valve between the tank and the water heater.
So the placement at the meter in that township is null and void. Couple that with the one authority increasing static pressure to 100+ PSI means that all tank jobs will also need a PRV. People [HO] don't understand the cost or why as a plumber I was constantly being asked questions. I put a page on the web site now they can read it
take a look ....

TheMaster · 06-15-2010, 05:31 PM

Quote:

Originally Posted by Protech

Back in mid-2009 dunbar plumbing (known as roast duck at that time) posted some pics of a water heater with out of plumb heater connections at the top. I believe the cause of the failure was water hammer.

Read here: http://www.hotwater.com/bulletin/bulletin11.pdf

Thermal expansion can cause the same.

Protech · 06-15-2010, 06:55 PM

I don't see the cpvc handling the kind of static pressure it would take to deform a tank. Now if it was a galvanized system it would be a different story.

Quote:

Originally Posted by TheMaster

Thermal expansion can cause the same.

PlungerJockey · 06-16-2010, 02:43 AM

Quote:

Originally Posted by TheMaster

Thermal expansion can cause the same.

As much as it hurts, I agree with him

grandpa · 06-16-2010, 11:29 AM

I don't know whose technical bulletin that is, so I will take it a face value. I would not have expected water hammer....normally a brief occurrence...to cause deforming of the shell. So be it.

One thing I have seen for sure....at HD when water heaters come off the truck, they are 4 to a pallet and I have peeked back into receiving and seen them stacked 5 pallets high. Those heaters on the bottom of the stack are tweaked! I have seen wh out in the store with the nipples bent, and I assumed it was from the stacking.

DUNBAR PLUMBING · 06-16-2010, 12:39 PM

I've encountered this problem more than once...and I actually have a few pictures of the ones I replaced, somewhere on my hard drive.

I'm not sure what caused it....but I'm thinking heat and a serious negative force. I've even seen the tops and bottoms bubbled out like a soda can in a freezer.

All I can say that most times, high pressure was part of that equation almost always, and there was no check valve at the meter or otherwise.

I was thinking possibly a hard pressure loss from hydrant cleaning or nearby fire where the fire department was called upon to save lives, and hence the hard drop in pressure without protection to the plumbing systems.

Protech · 06-16-2010, 03:42 PM

So vacuum damage then?

TheMaster · 06-16-2010, 03:46 PM

Read here...all of it: http://www.hotwater.com/bulletin/main4.html

06-15-2010, 03:50 PM	#1
Protech ٩(͡๏̯͡๏)۶ Join Date: Sep 2008 Location: Polk County, Florida Posts: 7,167 My Photos	I think I may have solved the mistery.... Back in mid-2009 dunbar plumbing (known as roast duck at that time) posted some pics of a water heater with out of plumb heater connections at the top. I believe the cause of the failure was water hammer. Read here: http://www.hotwater.com/bulletin/bulletin11.pdf __________________ Plumber, Repiping, Replumbing, Leak Detection, Solar Water Heater, Drain Cleaner, Pipe Leak, Polk County Plumber, Lakeland Plumber, Winter Haven Plumber, Haines City Plumber, Bartow Plumber

06-15-2010, 03:52 PM	#2
Protech ٩(͡๏̯͡๏)۶ Join Date: Sep 2008 Location: Polk County, Florida Posts: 7,167 My Photos	"Water hammer is the destructive forces, pounding noises and vibration in a piping system when water flowing through a pipeline is stopped abruptly. When water hammer occurs, a high intensity pressure wave travels back through the piping system until it reaches a point of some relief. The shock wave will then surge back and forth between the point of relief and the point of stoppage until the destructive energy is dissipated in the piping system. The violent action accounts for “banging”, “thumping”, and/or intense vibration in the pipe line. Although noise is generally associated with the occurrence of water hammer, it can occur without audible sound or noise. Quick closure always causes some degree of shock with or without noise. The common cause of water hammer is single lever faucets (sinks/lavatories) or automatic solenoid valves (dishwashers, washing machines, etc.). The speed of the valve closure time is directly related to the intensity of the surge pressure." "The damage from water hammer can manifest itself in a number of ways. The most common are: · Expanded Tank Shell - This can be demonstrated by measuring the circumference at various locations along the shell. Pressures in excess of the maximum design working pressure can cause permanent deformation of the shell. · Collapsed Flue Tube - This will choke off the ability to vent the products of combustion causing the flame and/or combustion to spill out from the combustion chamber. Often this will occur where thinning of the flue tube walls has occurred due to contamination of the combustion air or because of excessive condensation. · Inverted or Deformed Tank Heads - Often this accompanies collapsed flues, but one or both heads can be deformed." __________________ Plumber, Repiping, Replumbing, Leak Detection, Solar Water Heater, Drain Cleaner, Pipe Leak, Polk County Plumber, Lakeland Plumber, Winter Haven Plumber, Haines City Plumber, Bartow Plumber

06-15-2010, 05:20 PM	#3
PLUMBER_BILL The Old (antique) Master Join Date: Oct 2009 Location: ALLENTOWN, PA Posts: 930 My Photos	[quote=Protech;120658]"Water hammer is the destructive forces, pounding noises and vibration in a piping system when water flowing through a pipeline is stopped abruptly. <snip> All new homes we have done for the past 13-14 years have had thermal expansion tanks installed as all new houses have backflow valves. Not RPZ or testable double checks. The muncipal authorities install Watts # 7's Now the placement of the tanks was where the water came in on the house side of the meter. This did two things, took care of the thermal expansion, but also gave each house a shock absorber. Now older homes are getting a meter changeover with backflow. We have an inspector here [yep there charging a $54.00 permit fee to install a tank] that won't allow a tank to be installed if there is a valve between the tank and the water heater. So the placement at the meter in that township is null and void. Couple that with the one authority increasing static pressure to 100+ PSI means that all tank jobs will also need a PRV. People [HO] don't understand the cost or why as a plumber I was constantly being asked questions. I put a page on the web site now they can read it take a look .... __________________ Bill Parr LMP www.parrsplumbing.com click on ... A little of this and a little of that Last edited by PLUMBER_BILL; 06-15-2010 at 05:22 PM.. Reason: spelling

06-16-2010, 12:39 PM	#8
DUNBAR PLUMBING www.DunbarPlumbing.com Join Date: Sep 2008 Location: NORTHERN KENTUCKY - GREATER CINCINNATI AREA Posts: 4,495 My Photos	I've encountered this problem more than once...and I actually have a few pictures of the ones I replaced, somewhere on my hard drive. I'm not sure what caused it....but I'm thinking heat and a serious negative force. I've even seen the tops and bottoms bubbled out like a soda can in a freezer. All I can say that most times, high pressure was part of that equation almost always, and there was no check valve at the meter or otherwise. I was thinking possibly a hard pressure loss from hydrant cleaning or nearby fire where the fire department was called upon to save lives, and hence the hard drop in pressure without protection to the plumbing systems. __________________ Northern Kentucky Plumbers *\|YOUTUBE VIDEOS\| Twitter Feed \| DUNBAR PLUMBING FAN PAGE*

06-16-2010, 03:42 PM	#9
Protech ٩(͡๏̯͡๏)۶ Join Date: Sep 2008 Location: Polk County, Florida Posts: 7,167 My Photos	So vacuum damage then? __________________ Plumber, Repiping, Replumbing, Leak Detection, Solar Water Heater, Drain Cleaner, Pipe Leak, Polk County Plumber, Lakeland Plumber, Winter Haven Plumber, Haines City Plumber, Bartow Plumber

06-16-2010, 11:29 AM	#7
grandpa Senior Member Join Date: Jul 2008 Posts: 392 My Photos	I don't know whose technical bulletin that is, so I will take it a face value. I would not have expected water hammer....normally a brief occurrence...to cause deforming of the shell. So be it. One thing I have seen for sure....at HD when water heaters come off the truck, they are 4 to a pallet and I have peeked back into receiving and seen them stacked 5 pallets high. Those heaters on the bottom of the stack are tweaked! I have seen wh out in the store with the nipples bent, and I assumed it was from the stacking.

06-16-2010, 03:46 PM	#10
TheMaster Registered Member Join Date: Jun 2009 Posts: 6,437 My Photos	Read here...all of it: http://www.hotwater.com/bulletin/main4.html

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode