Looking for small air tank with connections on the ends

[LDO]

Something like the two gallon tank in the photo. It’s a thermal expansion tank for a water heater. It would be ideal, except it has a bladder splitting the tank in two; one side for air, one for water. Another option would be to remove the bladder, but I don’t know of a good way to do that and get everything out of the tank through a 3/4” hole. 

[peteski]

What are you planning on using it for?  Are you sure it will be safe for the pressures you are planning for it?  Exploding metal tanks are not fun to be around of.

[LDO]

It’s for a “Nerf RPG”. It will launch projectiles made of foam insulation. Pressure will be no more than 100psi

[johnyrotten]

Horn Blasters sells good tanks on Amazon. They have them down to around a half gallon size. Vai-air is another option. These are actual pressure vessel tanks, so there's a safety factor and less risk of a suprise. 

[TECHMAN]

2 hours ago, peteski said:

What are you planning on using it for?  Are you sure it will be safe for the pressures you are planning for it?  Exploding metal tanks are not fun to be around of.

Harbor Freight carries portable air tanks that would be safe, have air connections included, and are about the price of a model car kit.....  food for thought......

DJ

[Mike 1017]

I would look for something like this on the tank. Some sort of certification

[Ace-Garageguy]

You simply need to look for a sticker (or stamped into the metal) indicating that the tank conforms to the relevant ASME (American Society of Mechanical Engineers) specification.     https://www.asme.org/certification-accreditation/boiler-and-pressure-vessel-certification

It's worth doing some homework to insure you don't have an unexpected boom, with flying steel shrapnel.

Offshore manufacturers are notorious for fudging compliance data, so make sure whoever you buy it from has enough insurance to pay your medical and rehab bills, and whatever post-boom prosthetics may be required.

 

 

Edited September 5 by Ace-Garageguy

[LDO]

It will see very little pressure. I built something very similar to the Nerf RPG idea a few years ago. It’s a bait launcher. It can launch a 2” diameter plug of ice with bait in it, for fishing off the bank of a lake or pond. I tried it at a school yard and it went 91 yards with 60psi in the tank. The trigger is a slightly modified sprinkler valve. It’s a fast acting valve that only used 35psi for the launch. I’ll try to post a pic of the bait launcher this weekend.

[LDO]

This is the bait launcher. Cool for sitting on the ground and slinging frozen liver into a lake. Not so much for launching projectiles made of pipe insulation. It has a pressure gauge so that it can have consistent trajectory. The trigger is a modified sprinkler valve that opens and closes so fast that it uses 35psi from a tank aired up to 60psi. I want the RPG to have everything in a straight line. Better for a toy that looks somewhat like a shoulder fired rocket launcher. 

Edited September 6 by LDO

[JollySipper]

That reminds me of the potato launchers that were popular around here for a while! Much cooler as a bait launcher................ The way a lot of them worked involved hairspray and a grill lighter!   

[Ace-Garageguy]

Just a thought...the smallish tanks AC refrigerant comes in are available free (once they're empty) everywhere. 

Not hard to put a fitting in the "other" end for the low working pressures you're talking about, or the just use a T-fitting to fill it.

I used to pull 'em out of our scrap metal dumpster for future projects, but I have way more than I'll ever need.