Spence Steam Pressure Reducing Valve Failure Analysis Teardown

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Күн бұрын

Пікірлер: 25

@nightone9720 Жыл бұрын

Great technicians are the ones who NEED to know why. Thank you for sharing your investigation! Stay safe out there everybody!

@mikaeljiskovkristensen7861 Жыл бұрын

In Denmark where i live, i had changed a few pressure reducing valves. We mostly use spirax sarco and some places uses cheap ari valves. I must admit, there are very few good valves left on the market. Even clorius stopped producing their iconic weighted TD58 valves and danfoss stopped producing their good and welknown IVD-IVF regulators, that have the ability to control both district heating hot water, and steam at a temperature of 180 degrees celsius. All the new valve types is cheaper, but fails more frequently. I mostly worked on industrial process steam systems. The best content i wish you create, is disassembling that valve on camera. I like to disassempe things.

@IsaacArey 2 ай бұрын

Excellent teardown. I'd hazard that steam hammer from interaction with cold condensate could cause intense stress to the seat. Great to see different failure modes and their explanation. Thank you.

@gordonschweizer5154 2 ай бұрын

Thank you for the kind words! I installed this unit and it was in service for some 15 years and gave excellent service. There was no water hammer that I could detect (admittedly, my hearing isn't great). The unit worked, until suddenly it didn't.

@DarrinPratt Жыл бұрын

Thank You. I'm about to tear into one of these for the first time to rebuild. I was looking for what to expect inside. Now I have an idea on what Ill find. Good Video! Thanks Again

@edwardgonzalez3072 6 ай бұрын

Thank you so much for sharing! Great video

@gordonschweizer5154 6 ай бұрын

You are so welcome!

@bryanfontaine9627 11 ай бұрын

Great video. Thanks. Quick question. Was the valve hunting low for the set pressure or not working at all? In my limited experience, when it is hunting, the diaphram plates are torn. I have one right now that's not doing anything. Now I think it might be this seat. It's a Hoffman valve, not Spence.

@gordonschweizer5154 11 ай бұрын

Thank you! In regards to your question: While I have heard of a PRV "hunting", I myself have to date never witnessed it to my knowledge. This valve simply stopped working, and the only way I could get it to cycle open was to remove that little 1/8" bleed-off plug on the "swoop" of the valve (steam came out of there while the valve was on... is that normal?). I thought it was a broken diaphragm, but there was no evidence of that when I took it apart (did I miss the cracks?). I then set the valve aside for awhile, threw the diaphragm away, and was going to scrap this thing, and I started to take it apart further for the Lols when I came across the broken seat as you see here. Did that really cause this valve to fail closed? For me, almost always if the main valve does not open, its the pilot valve's fault. Blocked orifices are also an issue. In this case, the pilot valve was working and was re-used when I changed out the main valve.

@bryanfontaine9627 11 ай бұрын

@@gordonschweizer5154 I took my diaphragm plates out and there were more tears in it than I’ve seen before. No wonder it just stopped working.

@davidlampe4153 Жыл бұрын

Wire draw suggests that the device is oversized I’m drawing from the video you did on F&T traps in which the seat might become wire drawn due to the float not lifting high enough? So I’m guessing that the distance traveled away from the seat if too small accounts for the wear?

@gordonschweizer5154 Жыл бұрын

I'm not sure, but I don't think the wire drawing shown on the seats is not bad. The unit was in service over ten years. The size of the unit it replaced was 3". WAY oversized. I totaled up the connected load and a one inch prv would have been too small.

@shottputter Жыл бұрын

Good Video. I have many of those valves in my shop at work. The valve not opening is interesting to me, especially since you mentioned the diaphragms being intact when you took the valve apart. Was the 5A elbow in the bottom plugged? Also, did the seat break when you tried to remove it or was it broken when you took the valve apart? I have lots more questions, but I'll stop there for now. @@gordonschweizer5154

@gordonschweizer5154 Жыл бұрын

@@shottputterThanks! The seat was found broken when I opened it. It appeared to have allowed steam to enter the area on top of the diaphragm so the valve could not be stroked open. The little 1/8" plug on the "skirt" was removed & and steam hissed out and the valve cycled open and started heating the building. It ran that way for the rest of the season. I tried calling the rep to see if they had any ideas as to what was going on, but, as you may know, anyone with any knowledge on these valves was liquidated.

@shottputter Жыл бұрын

Thanks for responding. It is too bad the factory has closed and moved. Luckily I have a line on a guy that has been working on these for over 40 years, so I go to him when something strange happens that I cannot figure out. I've had numerous valves refuse to open, but never thought of removing the 1/8" plug in the base to relieve pressure and encourage the valve to open. I'll add that trick to my bag incase I ever need it. @@gordonschweizer5154

@hankscorpio6111 11 ай бұрын

I have one of these that I'll be tearing into in a bit. I rebuild the pilot valve and it's allowing steam through w/o the pilot sending steam to the main valve diaphragm. So obviously there's either an obstruction or something's wrong with the disc/seat. I haven't had to rip the main valve apart before so I thought I'd take a peek on KZbin Thanks again glad I did. This doesn't look to bad.

@hankscorpio6111 11 ай бұрын

Broken spring~!

@gordonschweizer5154 11 ай бұрын

This particular valve early in its history had debris caught under the seat 2x and caused the sanctuary to overheat. The organist for the church then would go down and beat on this valve with a hammer to get it to close. I guess it was more satisfying to do that then shut the upsteam ball valve.