This one disassembles this combination pressure and temperature relief valve. I explain the temperature portion of the valve and the rather simple action of the pressure relief.
I gotta say I watch a lot of hvac videos on RU-vid from several dozen channels and yours are consistently some of the most useful to me. You’re exceptionally good at explaining and demonstrating these concepts in a plain and understandable way
Holy Taco pumps!! I started watching your videos after I took one of your classes in early 2015 and I just saw that your videos have been viewed almost 49 MILLION times! Thats awesome. Thanks for taking the time to do them. We appreciate it.
Thanks for the video, great training for some of my home inspector friends. Watts recommends yearly inspection by opening and closing the valve, and every 3 years having a plumber remove and inspect the valve. This is written on the yellow plastic tag attached to the valve. More in-depth info used to be on their site, but due to a recent remodel, this is now very difficult to find.
Man I can't seem to find anything on these because I'm curious about shank length. Found one about an inch shorter than original but I don't see anything crucial about length. Besides maybe some surface volume 🤔. Any who, when GFM popped up I already knew I was going to get some quality information I never knew I needed. Big fan here. My college hvac/r instructor turned me onto you in 2014/15. Here in fresno calif. Whats funny is we seen a video of a water heater explosion during safety class and I remember him saying his wife was puzzled how that could happen and he said to her, that shouldn't happen ever it's next to impossible someone somebody did something they weren't supposed to do. It's literally the reason I can't just use the inch shorter shank valve haha. 3.5in I guess I need 4in. But he literally beat every single subject, theory and science into us including safety. Big thanks.
I would imagine that the temperature probe works exactly the same way as a coolant thermostat on an engine, the wax melts and the liquid is less dense than the solid so it takes up more volume and forces out the pin via hydraulic pressure.
wax motor, 'aka' linear actuator :) you got it on the temp relief. the spring/compression height is obviously the pressure relief control.. that being said, as the rubber/nylon/ptfe disc seal compresses with age/thermal cycling the spring height changes as does seat pressure... yeah, this thought is well beyond plumbing/hvac and heavy into mechanical/engineering lol
One thing is for sure. Before assuming the t&p valve is bad and replacing it, you always check the p.s.i. and temp of the water heater/boiler. Too often ive heard my plumber buddy say. "I replaced the damn thing and found out the setpoint was too high". Lol
More specifically, this invention relates to an improved thermal relief valve of the type described in U.S. Pat. No. 5,641,119, which is incorporated herein by reference. In that patent, a thermal relief valve is described as suitable for conventional or miniature fluid piping systems. The thermal relief valve includes a cylindrical valve body with a bore that houses a thermal actuator. The actuator has a piston and wax that melts and expands at a predetermined temperature. When fluid temperature exceeds the predetermined level, wax expands and causes the piston to extend, thereby moving the thermal actuator axially within the housing. The actuator moves from its normal closed position in which the actuator engages an O-ring seal to an open position in which the actuator unseats from the O-ring and forms a gap therebetween. Fluid may then pass through the valve, flowing first through an annular passage between the circular exterior of the thermal actuator and the circular interior wall of the bore in the valve body that houses the actuator. The fluid next flows through the gap adjacent the O-ring seal and exits the valve.
B&G had or still has heat motors that worked on that principle in zone valves. Some kind of wax or something inside would get hot and expand opening the zone valve.
I would think the material inside the tube is similar to the wax in a taco zone valve head that expands at a set temp and maybe contracts when it cools down . Retired master plumber.
I've replaced a T&P valve that failed once, I'm not a plumbing expert by any means but I understand how a water heater works and that the T&P valve is a safety feature that can save your life in the unlikely event a thermostat is locked up and the hi limiter fails. I always wondered how the valve works to provide high pressure and high temperature protection in one device.
@@NZ2STROKE it became jammed with minerals. I was testing it by flipping the lever to make sure it can relieve if it needs to, and the water wouldn't stop and kept dripping when I let go. Exercising the lever didn't help and I think the water heater in question was close to 10 years old. But you're right, if the valve is dripping there's likely a reason, thermal expansion is a more common issue than you might think because many local plumbing code require a pressure reducing valve or check valve at the water meter to prevent contamination of the water main if there's ever a sudden drop in water pressure.
it could be combo wax/alcohol motor, alcohol or \similar, liquid behind the wax, wax just used as a seal/buffer. it staying out could be due to passing the motors spring thermal rating, maybe it melts also.never cared to dissect one
Very interesting. There is lots of information on the web related to how they are supposed to work but virtually nothing about how they are constructed so that they do work. Have you done a video on the old style thermocouples? I've always wonder how they work. I have about 15 of them that I saved after they were taken out of service.
On the topic of water heaters, are you familiar with a product called Mag-Erad? I saw an ad on Facebook for it the other day. I guess it is for descaling a tank water heater. I thought about getting some to test out.
Does the prove has to be in contact with water? I got a little water heater with the valve on top but I would like to install a elbow and connect it to a pipe so it can be installed horizontally, would that work? It won’t fit unless I do that. Thank you
Sir if you don't mind ~ our issue with outside AC: When we turn it on it runs fine - as soon as it runs awhile - it goes off and you will hear the compressor come on and the click, but the big fan won't start back - is it a relay problem do you think?
@@BlessedFloridaMom If the outdoor fan stops, and the capacitor has been replaced. the fan motor is probably failing. Check to see if the motor is hot. GFM
Thank you Thank you!!!! You are so wonderful to share your knowledge.... We watched your videos and learned about the fan motor and yes thats the key we think as well - we finally got tired of being ripped off! Do you believe we paid $300 for a fuse that when we took the cover off was sitting in the front???!!!! Now that I am learning about this stuff I am insulted! A friend of my neighbors who runs his own outfit today came for free and confirmed just what you said - fan motor - you are wonderful!!! Thank you and God Bless you and your work!!!
@@grayfurnaceman it shouldn’t cause the mechanism to stop working though right? I can still open and close the valve (had to re-tap the pin to seat it again) i’m very light tapping with barely much force using a rubber mallet
@@Ultrajamz You are doing correct with the rubber mallet. These valves are are pretty much idiot proof. Even if the lever is clamped with a C-clamp, (yes, I have seen this) it will still relieve. GFM
