Does anyone have a date or reference point for when a TPRV was required on a water heater. I don’t need it for a report, just doing some writing and to cure my own curiosity. Thanks guys.
…after repeated explosions? 
Yup, that is the third one I have installed in my home in the last 2 months. I keep putting that cap on the end of that pipe thing, don’t know what the heck is goin on!!:mrgreen:
Okay, now does anyone know when they started requiring an extension to be put on the TPRV?
Nope, but I would assume at the same time as the TPR.
Did you locate the answer to when the TPR was required? Please share for our education also.
Like it was said above, back in the 1800’s when the first steam vessle blew up. :mrgreen:
Code dating is not important anyways. All boilers and water heaters simply need a PTR valve.
Interesting… but… doesn’t answer Ian’s original question…
Appears that it was madated on or shortly after this video in 1939.
http://www.watts.com/mediaCenter/ Click on Educational and watch “Explosions
Danger Lurks” 15 min. 
Marcel, great video. I actually have this video, released by Watts on DVD. The DVD case states it was originally filmed in 1948. At the end of the video, it recommends municipalities adopt regulations for safety, “as some have already done”. That may be the closest thing to an answer we get. Thanks for the link, and the reminder of the video.
Which is why it is not for my reports. like I said. I was looking for this info for an article, so I was curious.
Looks like the requirements for the valve were as Marcel said around 39, have not found info as far as the extension requirement.
thanks Marcel thats great info to know
Well glad some liked it and I have to acknowledge the help from a friend in Texas Mr. Barry Adair. Great help to many members in the past and present.
Thank you Barry.
Yes, thank you Marcel, and thank you Barry. Very much appreciated.