Vintage Double Hose

Burst Disk Port Repair
- A few years back, Sea Hunt Jerry gave me a junk Sportsways J-Valve for parts. The reason it was junk was because somewhere along the way the burst disk port got chewed up by a drill bit. Well, otherwise this was a good J-Valve and it is taper 1/2" NPT. It eventually got lost in my valve box and foregotten. Then one day I needed a 1/2" NPT valve and spotted this one. I put it on a tank and it leaked like heck from the burst disk port. Oh, I tried O-rings, gaskets, whatever but there just wasn't a good flat seal in the bottom of the port.
- Then one day, I thought about the machine shop we have at work. A simple plunge cut with an end mill would clean up the bottom of the port. And a tap with the point flattened would extend the threads to the bottom of the port. This looked like a perfect solution but the newly machined port was too deep for the new PRD (burst disk)... It would stop against the top surface before it could bottom out and seal. So, back to the shop where we relieved the top surface just enough to screw the PRD deeper. Now it works perfectly and this nice Sportways J-Valve is going on s single 38 scuba tank!


- The tank I'm putting this valve on is 1800 psi working pressure. This would normally call for a 3000 psi burst disk. Those are hard to come by. So, I'm using the next best thing, a 3360 psi PRD (pressure relief disk - burst disk) which is indicated for tanks with working pressure of 2015 psi.
- The one piece PRD units replace the old combination of burst disk, washer, and nut. I got these from Dive Gear Express. They recommend installing the PRD at 100-120 in-lbs of torque.

very smart diy

Good move. I had that same issue on a valve once, but didn't think about milling down the valve body a little bit.

Installed, Sealing Nicely,... On my "Ugly Tank"

- I've been using this ugly black USN 38 cf tank as my test fill tank for working on compressors and filter systems. I took a plain Jane post valve off and swapped in the repaired Sportsways valve. I expected to find some moisture and maybe some oil residue inside. But it is clean and dry as a bone in there... So, my compressors and filters must be working well!

Maybe we should have an Ugly Tank contest. Here's my entry.

A Woman at Church gave this UGLy tank now its Ebens

I love to see something fixed and working again! Nice work, Eben.

Here's my ugly tank entry.
s-l1600 (14) by Vancetp, on Flickr

Omigosh Phil, you are clearly in the lead on ugly bottles, lungs, tanks and cylinders!
Nothing I have could compete with that.