Valve Question

[Creed]

I have a K valve that has a small hole in the threads. It is high up on the shaft, near the top. It connects to the tube, or at least, air blown through the tube comes out of it. It looks manufactured, and not a wear spot or a defect.

Now, not being familiar with valves, I assumed that it simply supplied pressure to the oring to increase the seal or something. However, when my old instructor looked at it, he was puzzled and said that he had never seen something like it.

So, is this a defect, or is it manufactured?

 

[boydski]

I have a K valve that has a small hole in the threads. It is high up on the shaft, near the top. It connects to the tube, or at least, air blown through the tube comes out of it. It looks manufactured, and not a wear spot or a defect.

So, is this a defect, or is it manufactured?

I've seem something similar to what you describe on a pair of brand new Beauchat Y-valves. I thought they were a defect, but both new valves had them, and they are in service and appear to be working fine. I'm not sure why they are there though?

 

[rab]

Is it a DIN/Yoke convertable? I've got Thermo valves and there is a hole to make sure that you have the DIN reg or the Yoke insert fully seated into the valve. It doesn't really sound like what you're trying to describe -- post a picture if no one gives you a good answer.

-Rob

Edit: Do you mean the threads that go into the neck of the cylinder? I'd venture a guess that it would be there for the same reason (i.e., making a poorly seated valve obvious at low pressure), but I've not seen that end closely.

 

[jonnythan]

Is it a DIN/Yoke convertable? I've got Thermo valves and there is a hole to make sure that you have the DIN reg or the Yoke insert fully seated into the valve. It doesn't really sound like what you're trying to describe -- post a picture if no one gives you a good answer.

-Rob

I think he's talking about the valve threads that go into the tank, not where the regulator attaches..

 

[SDAnderson]

I have a K valve that has a small hole in the threads. It is high up on the shaft, near the top. It connects to the tube, or at least, air blown through the tube comes out of it. It looks manufactured, and not a wear spot or a defect.

Now, not being familiar with valves, I assumed that it simply supplied pressure to the oring to increase the seal or something. However, when my old instructor looked at it, he was puzzled and said that he had never seen something like it.

So, is this a defect, or is it manufactured?

Bleeder holes are common on the outlet side of DIN valves but I've never seen a bleeder hole on the inlet (tank) side of any valve. Who made the valve and how old is it?

 

[oxyhacker]

It's a bleeder port, like reefraff says. It's purpose is to allow pressure to vent, should someone try to unscrew a valve while there is pressure in the tank, before the valve can be undone far enough to blow off.

 

[Creed]

OK, here is a picture of the bleeder hole, for those who didn't know what I was talking about. The picture is kind of fuzzy, but it's that black spot in the center of the thread. Thanks to Vance, for letting me know what it was.