TPR valve on water heaters.

[Law3]

Hello, I am a Home Inspector in the Houston TX area. I have a question about the TPR valve on water heaters. Does the T&P (Test and Pressure) valve on water heater need a 6 inch metal pipe lead-out immediately after the valve before being connected to CPVC pipe?
Is there a plumbing code for this?

 

[Breplum]

"temperature"/pressure relief valve". there is no metal pipe rule, as cpvc is made for hot water. Most ideal cpvc threaded transition fittings have metal threads.

 

[Sponsor]

 

[GReynolds929]

@Breplum is correct, I would add that the material used has to be approved for hot water distribution, and no restrictions to the ID (IE: PEX insert fittings).

 

[Law3]

@Breplum is correct, I would add that the material used has to be approved for hot water distribution, and no restrictions to the ID (IE: PEX insert fittings).

You bringing that up, we were taught that if you used PEX on the tpr valve, you would have to go one size up. But what about the copper corrugated tube. Would that be a smaller I D.

 

[GReynolds929]

I personally would not consider that restrictive. If an inspector is picky it might get called out.

 

[hj]

They wee picky around here and considered corrugated undersized.

 

[Fitter30]

Never decrease pipe size off a relief valve. Tp valve is set for 210° and or 150lbs.
Cpvc is rated to 200° i wouldn't want to be is the same room if the valve opened fully if there was a real problem. Metal threads to cpvc adapter is needed coming off tp valve all plastic fitting is rated to 150° if your going to use this plastic.

 

[Sylvan]

Hello, I am a Home Inspector in the Houston TX area. I have a question about the TPR valve on water heaters. Does the T&P (Test and Pressure) valve on water heater need a 6 inch metal pipe lead-out immediately after the valve before being connected to CPVC pipe?
Is there a plumbing code for this?

I was a federal low pressure boiler and unfired pressure vessel inspector for the postal service.

I went to OU for training ASME section IV and the NBBI codes and it was strongly suggested the T@P or relief or safety valves have a discharge pipe of either copper tubing or schedule 40 pipes with the ends cut in a 45 deg angle so no one could cap or reduce the the discharge pipe or add more fittings

I do not trust plastic as Fitter stated if the T&P discharges @210 deg it could cause a major problem