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residential service
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No, there was no gas explosion and nobody was hurt but I did almost wet my pants.

This has never happened to me before and I've never heard of it happening but it did today. I was replacing a gate type house isolation valve with a 3/4" ball valve. I was sweating the downstream joint which was just a few inches from the prv. There was very little water in the line so I had simply slid the valve on and began to heat the joint. THE VALVE WAS OPEN. When it was hot enough I began to introduce the solder. When the joint was almost complete, all of a sudden it sounded like a shotgun went off right beside my head and THE FULLY OPEN BALL VALVE "jumped" about 1/8" or so. It totally freaked me out. There was still very little water or steam present.

Why did this happen? Has it happened to anybody else? I'm wondering if it was prv related and was really concerned that I had somehow damaged it but when everything was complete I turned the water back on and everything worked just like it was supposed to. When you heat an unsoldered but closed joint in which water has been present, sometimes if you don't get enough of the water out, it will bubble and spit out of the joint. This never happened and besides the joint was not closed because THE VALVE WAS OPEN.

It startled me so bad that I nearly fell off of my ladder.
 

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Glad your o.k. Sounds like steam build up in a low spot or water rolled into a hot spot. The fact that you stayed on the ladder is the mark of a seasoned pro.:thumbup: I'm sure KILLER will be around soon to tell us what really caused that POP.:laughing:
 

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No not happened me yet, we as plumbers don't expect this thing to happen, but when they do, it does startle us.
 

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You sure the ball valve was open, it could have failed to open making you think it was in the open position. may not happen often, but I have found one that failed on me right front the start.
 

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Glad you weren't hurt

It startled me so bad that I nearly fell off of my ladder.
:thumbsup: Glad you weren't hurt. What would happen to your business if you were hurt and couldn't work for an extended period of time?

The above scenario is exactly why we felt staying a one man operation was too risky.
 

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residential service
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Discussion Starter #8
Was it a full port or reduced port valve?
It was a Hammond full port. I never use reduced port ball valves. This was however only about the 2nd or 3rd time I have used Hammond. I don't know much about them but from everything I can see it seems to be a quality product. If anyone knows otherwise please let me know.
 

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residential service
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Discussion Starter #9
:thumbsup: Glad you weren't hurt. What would happen to your business if you were hurt and couldn't work for an extended period of time?

The above scenario is exactly why we felt staying a one man operation was too risky.
If I went down it would be very bad. I agree about the one man shop being a potential problem and we are working toward changing that but we have to hit certain monthly revenue marks (and stay there) for a period of time before we can grow and we're just not quite there yet. We are getting closer but I don't want to buy another truck, equip it, stock it, and man it until I'm confident that it is going to stay on the road. If I can't keep a tech moving at least 40 hrs a week he won't stay long and it doesn't look like I can afford to hire a tech and then not run calls myself.
 

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If I went down it would be very bad. I agree about the one man shop being a potential problem and we are working toward changing that but we have to hit certain monthly revenue marks (and stay there) for a period of time before we can grow and we're just not quite there yet. We are getting closer but I don't want to buy another truck, equip it, stock it, and man it until I'm confident that it is going to stay on the road. If I can't keep a tech moving at least 40 hrs a week he won't stay long and it doesn't look like I can afford to hire a tech and then not run calls myself.
Can't you hire someone that has a truck and tools? It is not that uncommon here.


Hammond are a better quality import valve, I prefer Nibco myself.
 

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One of two things come to mind. Water soluable flux and the solder surrounded it allowing an air/steam bubble to form.

The other is you didn't cycle the valve before you installed it. Air trapped behind the Teflon seat perhaps.

Just a couple of dumb guesses.
 

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I always solder valves closed. I know if you open it while it's hot it sounds like a gun went off and usually blows the seals out.
 

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Seems as though it could be water in the ball valve, which leads me to wonder if the valve may have been damaged?

I've seen ball valves freeze and crack when they were open and not installed.
 

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residential service
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Discussion Starter #14
The valve had definately been cycled because I always like to show it to the ho so that I can demonstrate how it operates and why it's so much better than the gate valve that they currently have.

The valve was fully open and was only piped on the downstream side. I do it this way because often when you think you have it completely drained down, once you begin to heat the joint more water or steam will show up. If it is not piped on the other end and the valve is open and it is just a small amount of water you can still get it hot enough to produce a good sweat joint. If the valve is closed or it is completely piped up on the upstream side, there is nowhere for the residual water/steam to go and it will either not allow you to get the joint hot enough or it will blow the valve or fitting off of the pipe. In the case of a ball valve once the downstream joint is good, then you simply close the valve, pipe up the upstream side and sweat away with no problems. It all depends on which direction most of the residual water seems to be coming from. There always seems to be one side that drains pretty quickly and the other side that takes longer. In this case, as I mentioned, it was close to the prv so most of the residual water was coming from the downstream side. I could absolutely see this happening with a closed valve but I intentionally left an escape route for any residual water, of which there was very little. Additionally sometimes you have no choice but to sweat a joint that you know is going to catch any water that comes and I've had them blow apart so that I had to take them apart and start all over but I've never had one make this loud of a noise, in fact they really don't usually make much noise at all. I'm telling you though this sounded like a 12 gauge going off next to my right ear. The valve jumped and simultaneously cooled the joint so that it only traveled 1/8" - 1/4" before it stopped dead in it's tracks.

Now that I think back on it though I did have a difficult time getting the valve to slide onto the pipe. I assumed that the pipe must have gotten egged somehow but now I don't know if maybe it was something about the valve that I did'nt notice. I was at an awkward angle and couldn't really view the end of the pipe.

I don't know. I'm not sure if this mystery will be solved.
 

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I never heard of this but will make the analogy with hvac so please bear with me. When I pull a vacuum on a system, I have to turn my ball valves halfway to release any non condensables trapped behind the ball and the seat. There's always non condensables there as shown on my micron gauge when I turn the valve.

Maybe the same thing happened with the valve. You had moisture behind the seat and it expanded when you heated it?
 

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I had the exact same experience a couple of months ago. My recollection is a little hazy but I don't believe a valve of any kind was involved. I seem to remember I was just sweating on a coupling (pipe was open) Part way through really loud noise scared the crap out of me. Couldn't figure it out. My dad was with me (40+ years plumbing experience)- just shrugged his shoulders said it happens every once in awhile. Still looking for good explanation.
 
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