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Troubleshooting a blast pot with a Schmidt Thompson abrasive metering valve

BlastOne’s Master Technician, Kerry Cooper, discusses troubleshooting a blast pot with a Schmidt Thompson abrasive metering valve

 

So, by taking this hose off here and depressing the deadman we’ve established, if there’s no air coming out of here with the deadman depressed that is this pile of valve.

Now, if the air is escaping from that, we know immediately that it is nothing to do with the deadman and it’s nothing to do with the pile of valve. So that’s good. We’ve just established a quick way of finding in a pneumatic system what the problem was.

However, if I depress the deadman, there’s air coming out of that. I’ll let the deadman go on the air continuous, immediately, I know there’s something wrong with the deadman.

So, remember that by taking this hose off here to protest it, depressing the deadman, the air escapes from this. That means that there could be something wrong with the deadman. If there’s no air at all and I depress the deadman, it’s the pile of valve. So one, two, let’s work in sync. So, there you go, we’ve established that straight away.

The one thing to remember is to always check these hoses to make sure they’re in good repair. Don’t leave them out where they’ll get run over or caught on something and that’s why we take them to the primary blast hose.

So, now, we can replace this particular hose because we’ve established what the problem may be.

Now, if I open the deadman and for some time, we’ve been alternating the Thompson valve to get grit to come through and nothing’s coming through, no grits coming out and we’ve wound the Thompson valve knob in and out, in and out. Still no grit. There’s grit in the pot. We’ve checked that there’s grit in the pot. That’s the first thing to do but we operate the deadman and we still got no grit. What do I do? What’s the easiest way to do?

Find out what in this pneumatic system could be the problem. As I mentioned before, first thing is take this off here, hold it out the way, compressed the deadman or depress the deadman. Air comes out good. So, now, I’ve got signal where nothing wrong with this, nothing wrong with the deadman, put that hose back on there. Do it up and you’ll see this capillary tube or signal air goes down into the auto air valve and then it goes down to the Thompson valve.

So, at the bottom of the Thompson valve, what I suggest you do is undo this hose off the Thompson valve. Bring that hose around here. Hold on to the hose, depress the deadman and see if there’s any signal air. If there’s no signal air, but you know there’s signal air here. That’s your Northern air valve. There’s something wrong with the wallow air valve. However, if there is air coming out of this hose and we’ve got no grit coming through, we know that it’s the Thompson valve.

So, there you are. How do I fault find on the pilot valve? Just told you. How do I fault find on your wallow air valve if there’s no air coming out at the bottom? That’s your Northern air valve. If there is air coming out at the bottom, it’s a Thompson valve.

So, during this process, we’ll show you how to repair the Thompson valve in such a manner that it allows grit to come through and your functionality is restored.

So, remember, it’s all in sync, this valve actuates to that value, that valve actuates the Thompson valve – one, two, three pilot valve, wallow air valve, Thompson valve.

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