Schrader fitting, for setting tubeless tires (small & motorcycle etc)

Sodo · Feb 17, 2015

I welded a 1/2" ball valve 'onto' this tank today, and the last part of the project is the fitting on the end of the hose. Or maybe paint.

Where do I get a fitting that will screw onto a schrader type tire stem, and flow as much air as possible? It has to be wide-open, with no obstructions. I have seen them just don't know what it's called.

I will use it mostly for motorcycle tires. If it works for my tractor front tires (23x8.50-14) I will be happy too.

Looking4new · Feb 17, 2015

Why not just pull the core out of the tube/tire valve stem and attach your chuck to it and blow away. You do need a gauge on the tank so you will know at a glance how much air pressure you have. Gemplers should have the chuck you need. Air Chucks

pmsmechanic · Feb 17, 2015

I would pull the valve off and add a + style pipe fitting. Plumb in a gauge, a schrader valve and most importantly a safety that won't let you put in more than 60 lbs pressure.

The more I think about it I wouldn't use this tank at all. It's a one time use only tank. Your playing with a time bomb as far as I'm concerned. A propane tank will do the same thing and is far safer (rated to 350 lbs) and has pipe fittings so that there is no welding involved. I'm not saying your a poor welder, I'm saying why take the chance.

If you do use the tank then at least pressure test it. Fill with water. Add a grease zerk and pump grease in till you get to about 300 lbs pressure.

Sodo · Feb 17, 2015

I thought about a propane tank, the volume seems more likely to work. Propane tanks are heavier duty, and expired ones are dime-a-dozen. But I don't envision this tank seeing a lot of cycles. I'll bet it will see less than 25 uses total, not a significant number of cycles for steel. What I want to know is "What minimum volume at ~115psi will do the job?" To to use minimum size tank I'll need the maximum flow thru the valve stem hence the quest for a connection that has no schrader bits in the flow path.

P you should know by now I'm not worried about the weld - 115 psi on a 1/2 sq inch is 57 lbs. I could hang my pickup on that weld.

As you can see there's not much time or $ into this part of the project. If I need a larger tank, its easy to remove my parts and throw away the throwaway, i've put more time into welding test-plates (not by much

). But it will tell me if the volume necessary, and a bigger tank won't tell me the minimum. Good idea about proofing, that's easy, can do it all in a pipe extension to be certain there's only water in the tank - thanks I'll remember that method !

Anyway, my main quest for now is an inflator head that attaches to a Schrader stem and in searching there are lots of options in the bicycle inflator market. They have many that clamp with a quick-release rubber seal only gripping the outside threads. I think I can remove the pin and then the plunger part can be cut out for full flow. Seeing as I only need a "seal" for about 1/2 second this may be the way to go. Also there are CO2 inflators that have schrader connection "parts" but can't really tell how wide open the flowpath is.

Mace Canute · Feb 17, 2015

A little FYI about these cylinders. From https://books.google.ca/books?id=Ah... service pressure not to exceed 80 ...&f=true

178.65 Specification 39 non reusable non refillable cylinders a Type size service pressure and test pressure A DOT 39 cylinder is a seamless welded or brazed cylinder with a service pressure not to exceed 80 percent of the test pressure Spherical pressure vessels are authorized and covered by references to cylinders in this specification 1 Size limitation Maximum water capacity may not exceed 1 55 pounds 1,526 cubic inches for a service pressure of 500 psig or less and ii 10 pounds 277 cubic inches for a service pressure in excess of 500 psig 2 Test pressure The minimum test pressure is the maximum pressure of contents at 130 F or 180 psig whichever is greater

From http://www.amtrol.com/media/documen...ry/Refrigerant_Cylinders_Brochure_MC10229.pdf

Sodo · Feb 18, 2015

Thanks MC thats great info. Looks like test pressure is 260psi. My compressors all max out at ~125psi so I think thats OK.

I wonder what psi the original helium was.

Sodo · Feb 19, 2015

Looking4new said:
Why not just pull the core out of the tube/tire valve stem and attach your chuck to it and blow away. You do need a gauge on the tank so you will know at a glance how much air pressure you have. Gemplers should have the chuck you need. Air Chucks

Definitely need to pull the core out! Thx for the link to Gemplers.

I think this is the item I need. As far as I can tell, it has no internal shutoff, requires a valve upstream, so I'm assuming it's purpose is full-flow. I'll run a larger hose out of the ball valve, then reduced down at the air chuck.

Looking4new · Feb 19, 2015

Sodo said:
Definitely need to pull the core out! Thx for the link to Gemplers.

I think this is the item I need. As far as I can tell, it has no internal shutoff, requires a valve upstream, so I'm assuming it's purpose is full-flow. I'll run a larger hose out of the ball valve, then reduced down at the air chuck.

View attachment 412982

No problem. I have them bookmarked in my tractor file.

aczlan · Feb 19, 2015

Just put a hose with a female quick connect on the valve and put together a double ended male quick connect to fill from your compressor. Then you can also use your "normal" air tools on it too.

Aaron Z

Sodo · Feb 19, 2015

I do that for my main portable air tank, but this tank…..my intention….is only to set beads on tubeless tires. Being its a "one-use" tank I don't want it to get too handy for other uses. If it works well I may add this huffin' feature to my OTHER portable tank which is of more robust construction but that's a later project.