Scuba tank help

Haysuse · Mar 12, 2014

I was wondering if anyone knows where to find the thingy that you use to fill one scuba tank from another. My buddy who sold me my Marauder said that this was a good way to keep one tank full while the other one was in the shop getting filled. Also, has anyone done much homework regarding the most accurate pellet for Marauders? I know each gun is different, but I would imagine that there has to some pellets that would be better overall. Thanks for your help, the gophers will hate you.

rl280 · Mar 12, 2014

Just U-TUBE Marauder pellets.

CJ1089 · Mar 12, 2014

Sounds like a trans-fill whip, a booster pump or a HP compressor.
One is $200, the next $2000 and the last $10,000.
Which one are you after?

Nwcid · Mar 12, 2014

I am a little confused here. The "thingy" is called a transfill whip.

I am not sure what problem you are trying to solve here. Transfill whips work by equalizing pressure so that both tanks will have the same pressure unless you stop the process early. If you have 1 full tank and 1 empty tank why would you transfill? Take your empty tank in and get it filled. I am not sure how long a shop takes to fill where you are but about 20 min will get a tank filled anywhere I go.

Haysuse · Mar 13, 2014

Thanks for all the help. My goal in this endeavor is to be able to keep one tank filled up with the other one, that way I always have one pretty full. I thought it was a simble tube/valve arrangement, I'll have to research further. Thanks again for all the info.

Nwcid · Mar 13, 2014

What you state you want to do is not possible. If you use a whip you will end up with 2 half (or how ever low) empty tanks instead of just one........

Fill both tanks. When the first one gets low take it to get filled and use the second one. Continue that rotation, it will be the most effective way to to it.

Artpro · Mar 14, 2014

I believe you should be able to refill smaller tanks form a larger one and still maintain higher pressure in the large one, maybe with a one way valve???

Nwcid · Mar 14, 2014

Artpro said:
I believe you should be able to refill smaller tanks form a larger one and still maintain higher pressure in the large one, maybe with a one way valve???

That is basically correct. But that is not my understanding of what the OP wanted to do.

With "tanks" you have 2 variables, pressure and volume, both have to be accounted for. A "one way valve" would be of little use since it works on pressure equalization. When transfilling what you end up with, unless stopped sooner, is tanks of equal pressure no matter the size of the tank. The amount of volume will depend on the size of tanks being used.

The "standard" SCUBA tank is the AL80 which is ~77cf of volume. So if you are using that to fill into a 5cf (not sure the bottle size on an air gun) you would get several fills, but each would have slightly less pressure. I am also assuming air guns do not fill to high pressures of SCUBA. There are formulas for figuring this stuff out. I have to do them often as I fill from HP single tanks into my LP double tanks for diving.

welder · Mar 15, 2014

Just get one High Pressure 3500 psi tank. You will be amazed by how many fill you get. If you tune your Marauder with a chrony you will get 40+ powerful shots witch is plenty for most hunting trips. You can get a smaller tank for the field if your shooting hundreds of shots. The .22 Crossman Premier hollow Points 14.3 grain are the most accurate in my M-rod (rifle) and P-rod (pistol). And i've tried a bunch of quality pellets. Don't waist your money equalizing the pressure on 2 similar size tanks . No benefit. Filling a small pony tank off a large tank makes sense to me. Good luck and have fun.

Haysuse · Mar 17, 2014

Thanks again for all the info, especially regarding the tanks issue. What Nwcid is saying makes sense, since he has a picture of scuba diving I'm gonna go with it! Since I'm now here in Montana (lucky me) getting the tank filled isn't quite as easy as it would have been in Oregon. I'm going to try the Crosman Premiers, I hear good things about them. I've had the best luck with some of my old RWS pellets, I've had them 40 years! I guess lead doesn't go bad very quick. I seem to get about 30 shots before the velocity drops, I don't really want to lower the pressure however. Thanks again!