Does anyone make an adapter to go straight from a AL80 tank to a standard pipe thread?

[broncobowsher]

Never seen a store bought adaptor. But old junk valve and cut the valve off and keep the brass plug that goes into the tank, that's easy. Brass drills and taps easy enough as well. Nothing crazy needed for tools to make one.

Got any old Propane tanks? The valve on those is already ¾NPT where it screws into the tank. and the standard BBQ tank is 5 gallons. They have an 11 year life span before needing requalification. I have 3 expired ones in my back yard. They are pretty stout. I have even drilled and tapped the bottom on one once.

As for PVC, I learned after I installed mine it wasn't a good idea. Finally changed it out before I had issues. Taking it out, I smacked a fitting with a hammer. I don't know how I got lucky that it never shattered on me with as easy as it broke with a light hit. There is a fair bit of PVC abandoned in my shop walls and ceiling now.

 

[happy-diver]

Tap some din inserts

My shop air plumbing is pvc. I didn't install it as it came with the purchase.
It holds up fine.

I don't know of a reducing bushing for modern tank threads.
I have thought of using the plastic plugs that come with new tanks for this. Simply drill and tap them for whater NPT thread your air system is.
It would probably hold low pressure fine..
My shop air plumbing is pvc. I didn't install it as it came with the purchase.
It holds up fine.

Ymmv.

@Akimbo thanks for the PSA which I probably should have included.

I am aware of the risk. Pipes are out of the way with few exceptions.

In prior operations it amazed me what osha focused on and what they ignored. Subject for somewhere else.

I have thought of using the plastic plugs that come with new tanks for this. Simply drill and tap them for whater NPT thread your air system is.

I am aware of the risk. Pipes are out of the way with few exceptions.

Stand up spin around three times blinking and recite I did not see what this bloke wrote

 

[PBcatfish]

Depending if you want to have a bleeder or not, either of these would work for a yoke valve -

YOKE BLEEDER, DELUXE - August Industries LLC

Our new deluxe style SCUBA Yoke Bleeder comes with an end port that is 1/4″ Female NPT. The new OVERSIZED bleed screw is now 1 inch in diameter. This makes the task of turning the bleed screw much easier. The bleed screw is not only larger but also stands up taller for easier use. All […]

www.augustindustries.com

Filling Yoke - August Industries LLC

A Scuba Filling Yoke and Knob with a 1/4″ female NPT connection for hoses. This yoke does not have a built in bleed and is most commonly used where multiple hoses are manifolded together and vented with a separate bleed valve. Also ideal for use in a transfer fill hose where two separate...

www.augustindustries.com

The air passage in a scuba valve is small, so you will get restricted air flow. My preference in your situation would be to cut off the top of the original valve, then drill & tap what's left of the valve to the NPT size of your choice.

Or, better yet, sell the old scuba tanks & buy a tank that is better suited for your use.

 

[noj3333]

Thank you everyone for the input.

Lots of comments... so I'll tackle them all here...

I'm using AL80's because I have them, and they have little value (besides scrap). Aluminum storage tanks for compressed air have a max PSI of 135... the scuba tank will easily be able to handle 150-200psi. I want AL and not steel due to corrosion. As for size, this will be for my small hobby wood shop. Currently I have a small 1.6 gallon (2hp) compressor, so a few tanks will greatly add to my capacity.

I'm going to cut the old valves off, and drill and tap what's left of the brass. I'll likely go to 1/4" or 3/8" for the new threads. Once drilled and tapped I'll mount them upside down to let water drain back into the lines, where I can draw it off as needed. The air lines will be 3/4" copper, because I have a lot that was salvaged from a retired plumber I know. I'll braze all the lines with 'hard solder', so the joints will be plenty strong, and the Type L copper should do well.

Again, thanks for the input everyone!

 

[ofg-1]

Just drill and tap the neck of the tank. For 160 psi, it shouldn't matter. Leave the standard valve in it.

 

[Tracy]

Drill a 7/16" hole in the side and run a 1/4npt tap in it. The walls are 1/2" thick. I have used many 6351 alloy tanks as accumulators and separators. They work well for that use. Leave the valve in place and mount it upside down with the dip tube removed. You then have a functional water drain.

 

[Eric Sedletzky]

Thank you everyone for the input.

Lots of comments... so I'll tackle them all here...

I'm using AL80's because I have them, and they have little value (besides scrap). Aluminum storage tanks for compressed air have a max PSI of 135... the scuba tank will easily be able to handle 150-200psi. I want AL and not steel due to corrosion. As for size, this will be for my small hobby wood shop. Currently I have a small 1.6 gallon (2hp) compressor, so a few tanks will greatly add to my capacity.

I'm going to cut the old valves off, and drill and tap what's left of the brass. I'll likely go to 1/4" or 3/8" for the new threads. Once drilled and tapped I'll mount them upside down to let water drain back into the lines, where I can draw it off as needed. The air lines will be 3/4" copper, because I have a lot that was salvaged from a retired plumber I know. I'll braze all the lines with 'hard solder', so the joints will be plenty strong, and the Type L copper should do well.

Again, thanks for the input everyone!

I think adding more tank storage with that small of a compressor motor will be problematic. Your small motor will not be able to keep up with that much volume. It will seem fine at first when everything is full, but then when you drain it out and low tank PSI kicks on the motor it will take forever to fill back up before the motor kicks off and you’re going to eventually burn out the motor and piston. Compressor motor size and CFM is balanced with the size of the air tank.
You’d be better of to buy a bigger compressor.

 

[broncobowsher]

That little compressor probably has a fairly short duty cycle. Designed for a short run time and a cool down period. Adding that much storage capacity should not change the total run time, but the cycles will be much longer duration.

 

[Eric Sedletzky]

That little compressor probably has a fairly short duty cycle. Designed for a short run time and a cool down period. Adding that much storage capacity should not change the total run time, but the cycles will be much longer duration.

It will add a lot more run time.
Lets say you have a 20 gallon air portable air compressor that pumps to 135 PSI, and you increase that tank volume to 40 gallons using the same compressor motor and pump it will run longer to fill that extra 20 gals of volume, actually twice as long. And you will not gain any CFM either. The motor and compressor are only capable of so much CFM according to their size. I know, i’ve been through this.
I used to run a mobile marine repair and at a lot of yards 120 volts was all we could get. I had to run DA’s and high airvolume air tools, so what I had to do was run two identical 120 volt portable air compressors and join the two outflow airlines with a Y connector. I was able to double the output (CFM) out of one hose. If the two were not set with exact kick on pressures then one compressor would have to do all the work ( if it could keep up with flow). But if air usage was enough to kick on both units then pressure would come right up fast.

 

[noj3333]

I appreciate the input on the tank size. The manufacture of the compressor uses the same 2hp motor on several models, all the way up to 20 gallon tanks. I would have to assume the duty cycle is engineered to fill anything between my small 1.6g factory tank, all the way up to the 20 gallon tank. After this project is complete I'll have 8 or 10 gallons of TOTAL capacity, and I'll still maintain a portable compressor that I can disconnect, with a quick connect fitting, and take on the road with me when needed.