Safety

Lance

There is nothing better than a relief valve when pressures get too high, unless they don't work. Its odd to me that so many people advise don't touch them. I have seen first hand the damage and danger when they do not work. We see a boiler or water heater once a year if we are lucky. The most important device many ignore. It should be tested and verified it works or replace it if it doesn't. Stock one or three, advise owner you will test and it could fail to open, fail to close, but you are ready with a replacement. Even when they do work damage can be done, but at least no explosions occur.
One day I went to a church to winterize and shutdown the heating, plumbing and gas as it would be left unoccupied and unused for a while. It was an old stone church about a hundred years old or more. What I found was my worst nightmare I thought I'd never witness in my life. I walked into a dry and hot steam boiler room, burner running wild, sap dripping from hundred year old timbers, melted plastic in puddles on the floor. A quick look alerted me the system was dry with a manual feed. Knowing from the dead men tales it wouldn't take much to blow this up in my face. I did an about face, as I walked out I threw the handle on the circuit at the door, heard the burner shutoff off and headed to make sure, one the water was shutoff and two the gas was shutoff at the main and called the fire department. I was worried the sap dripping on the flue pipe might light off. Returning to the boiler I asked what went wrong?
No one left to feed water to the boiler, thermostat wire laying over the boiler breaching going to a stack switch, melted and shorted, low water cutoff failed or bypassed by the short. Relief valve had blown off. It took over three hours for the metal's red glow to disappear. I than realized my client and I could have easily made two widows that morning. After the Firemen came and checked it all out and started to leave. I asked aren't you going to wait until it cools down in case of combustion? He said, you did what we would have done. Just call us if something happens. Go figure.
Hear the one about the Service tech walked into the furnace room and got real quiet? Lady of the house hearing silence thought to check on the tech, found him unconscious on the floor in front of the furnace. Monoxide spillage was the problem. We now carry monoxide detectors on our person.
We are called to solve problems and fix things. But are we always ready and willing? Be Safe.

BobC

40 years ago I thought I smelled something in the back hall of the apartment I was living in. I went down cellar and over to the landlords old Delco oil fired steam boiler that had a glowing red spot on it. I killed the power and opened up the outside door to air the place out.

This was in the summer, the boiler had a hot water coil in it but no LWCO so it fired dry. The owner was upset at me for killing his boiler but the installer told him better to replace a boiler than the whole damn house.

Bob

ChrisJ

BobC said:

40 years ago I thought I smelled something in the back hall of the apartment I was living in. I went down cellar and over to the landlords old Delco oil fired steam boiler that had a glowing red spot on it. I killed the power and opened up the outside door to air the place out.

This was in the summer, the boiler had a hot water coil in it but no LWCO so it fired dry. The owner was upset at me for killing his boiler but the installer told him better to replace a boiler than the whole damn house.

Bob

Isn't this one of the biggest causes of steam boiler explosions years ago? If some how some water happens to flow into the boiler.........you're gone. Not just the house, and maybe not just your house and family but perhaps neighbors, kids walking down the sidewalk etc.

BobC

The biggest threat were the old stack water heaters that ran of kerosene or an open gas flame. Most had no real temperature control and if the water started to turn to steam they could launch and leave a nice hole in the ceiling and the roof.

Boilers without LWCO's were even more destructive.

Bob

JUGHNE

There was a film (actually film) produced by the (I believe) Watts company who at the time was promoting the P&T relief valve for common water heaters.
They would set up the common 40/50 gallon water heater in a mock 10 X 10 house. House was as well built as most houses were, stouter than today actually.
The tank was full of water, valves off, no P&T relief valve. The controls were bypassed so the element was constantly on. After several hours the tank ruptured by pressure produced by water expansion, this allowed the superheated water to flash to steam as the pressure in the tank dropped . The tank took off thru the roof, the house was demolished. This was filmed by people in bunkers about 200' away.
The entire presentation was well done and very memorable.

It should be shown as a public service announcement, though it would have to be shortened as attention spans have dwindled.

I saw this at a trade show maybe 35 years ago...it was older than that....probably made in the 60's. Would be a good Utube for today, if anyone could find it.

KC_Jones

Mythbusters did this too.
https://www.youtube.com/watch?v=jbreKn4PoAc

ChrisJ

The Watts one is better than Myth busters, a lot better IMO.

https://youtu.be/5pVQryuKMj8

JUGHNE

Yes, much better. The one I saw might have been a little newer. As the guy with the pick-axe puncturing the cold high pressure tank had to wear a safety suit, heavy rubber with face protector. (The beginning of OSHA ).

I was a mere electrician at the time and knew I had to get diverse enough out here to stay above water. That is why I was at a plumbing trade show. For me this was very enlightening at the time. It introduced me to the power of steam which sparked enough interest to get me to the Wall today. There are still some water heaters with a pressure relief valve only. People don't realize the potential inside their tank. You see plugs in P&T valves on occasion because of dripping.
The newer version of this presentation (60's) was made because there were so many plumbers who said "we don't really to put your P&T relief valves on anymore.....there haven't been hardly any tank explosions.....do we still need them"!!

Thanks for finding that ChrisJ, I thought you would step up.
But there is still a little newer version out there.

nicholas bonham-carter

Great video, although a bit long for the general public.
Why does North Korea even need the H-bomb, when steam is waiting to serve them?--NBC