TPR Termination

[Richard W. Washington]

Originally Posted by rmccullough

Here is a link to Tech Bulletins for Rheem and Ruud Water heaters.

http://waterheating.ruud.com/dealers...displayNode=61

Go look at tech bulletin 1220, T & P Relief Valves, now who do you think knows which is a SAFE way to install that equipment. I would think the MFG. and would hold to their standards.

Since the MFG has the deep pockets you know they are CYAing themselves. MFG it is

[Joe Funderburk, CMI]

Originally Posted by rmccullough

Here is a link to Tech Bulletins for Rheem and Ruud Water heaters.

http://waterheating.ruud.com/dealers...displayNode=61

Go look at tech bulletin 1220, T & P Relief Valves, now who do you think knows which is a SAFE way to install that equipment. I would think the MFG. and would hold to their standards.

Playing devil's advocate here:

The document says water heaters "are pressure tested to 300 pounds per square inch (PSI) and have a working pressure of 150 PSI." Sounds like a 100% safety factor to me. So it's hard to imagine 4 elbows being OK but 5 makes the installation potentially deadly. Using RR's calculations as an example, the extra elbow may add a delay 1/10 of a second to the flow rate. 4/10 delay is OK. 5/10 is unacceptable?

The manufacturer's calls the information about not exceeding 4 elbows a "tip". Hardly a warning. Maufacturer CYA is right.

I agree you can play it safe and call out elbows > 4, but I still haven't seen any evidence that quantifies the hazard. I would have a hard time telling someone that 1/10 of a second makes all the difference between life and death when the whole system has a 100% safety factor for pressure.

[Russel Ray]

Originally Posted by jfunderburk

The document says water heaters "are pressure tested to 300 pounds per square inch (PSI) and have a working pressure of 150 PSI." Sounds like a 100% safety factor to me. So it's hard to imagine 4 elbows being OK but 5 makes the installation potentially deadly. Using RR's calculations as an example, the extra elbow may add a delay 1/10 of a second to the flow rate. 4/10 delay is OK. 5/10 is unacceptable?

The manufacturer's calls the information about not exceeding 4 elbows a "tip". Hardly a warning. Maufacturer CYA is right.

I agree you can play it safe and call out elbows > 4, but I still haven't seen any evidence that quantifies the hazard. I would have a hard time telling someone that 1/10 of a second makes all the difference between life and death when the whole system has a 100% safety factor for pressure.

The whole system has a 100% safety factor for pressure when there are no more than four elbows.

Just continuing to play the devil's advocate: Do you require hazard quantification for all other situations where the manufacturer provides installation instructions and "tips"?

I just let the manufacturer speak for himself. He has better attorneys than I do.

[jhugenroth]

Originally Posted by rray

I just let the manufacturer speak for himself. He has better attorneys than I do.

Yep. I don't argue with them.
Manufacturer's recommendations ALWAYS trump code.

[Joe Funderburk, CMI]

If you want to call a "tip" a recommendation, so be it.

[Russel Ray]

Originally Posted by jfunderburk

If you want to call a "tip" a recommendation, so be it.

Absolutely!

Notice that "tip" to "terminate unthreaded." Is there anyone here who would not call out a threaded termination?