Decided to share this in the case any other members have 3000 or 3300 psi SCUBAs they'd like to get the most out of. It's a long read so if you're not into that, you might want to avoid this whole topic.
So, my first couple PCPs were all either purchased with low pressure in mind, or were tuned to optimize low fill pressures. I have stated on here in the past that SCUBAs should not be over looked by airgunners. With that in mind, my first tank purchase was an 80cf SCUBA tank. Which is quite a bit of air, albeit low pressure air. For guns that only fill to 2100psi, 1600psi, and 1450 psi (my first three PCPs), that SCUBA is more than sufficient and offered a lot of shooting per fill. Well, my needs have changed and I now have 2 PCPs that need higher fill pressures, one to 250 bar, and the other to about 300 bar. 3000 psi is a little over 200 bar so a regular SCUBA tank cant utilize the upper end of the fill pressures of a regulated gun. End result of filling 250 and 300 bar PCPS with a 200 bar SCUBA? drastically reduced shot counts because the low pressure tank simply can't fill to high pressures.
That all lead me to purchase a 60 min Drager from Ebay, as well as one of the $40 fill stations, also from Ebay. I had heard of cascade systems used by dive shops and did some research. My searching led me to this product:
https://airtanksplus.com/product/tman-pcp-tee-block-air-splitter-female-foster-to-2-male-foster-fittings/ basically a Y that allows me to hook up the fill station from the SCUBA with the fill station from the SCBA to create a home cascade system.
Here is a picture of my actual setup:
Close up of the TMAN;
The black tank is the 80cf SCUBA with a Brancato fill station (rated to 4000psi). The blue tank is the 60 min SCBA with the ebay fill station (thicker hose). The red Y above and to the right is the TMAN splitter. Both female ends of the fill stations are hooked into the male inputs of the splitter. The highest point is the female foster that gets attached to the guns during filling. The procedure is to open the valve on the black tank (max 3000psi) and get the guns reservoir as high as possible with the low pressure tank. Then I close the black tank valve, still leaving everything pressured. I then open the valve on the blue tank and bring the pressure in the gun up to where I would like it to be. I then close the valve on the blue tank and vent the system using the better vent on the Brancato fill station.
I only fill the SCBA to 4200 to make things easier on all fittings and my Shoebox. Yes, I'm over the Brancato fill station rating by a little.
The theory with all of this was somewhat difficult for me to comprehend, so an example might help (or maybe I'm the only slow one). I usually refill my Veteran when it gets down around 110 bar (about 1600psi). If I only used the SCBA tank, the pressure in that tank would go down by a little more than 55psi, every time I filled the gun. That means I would only get about 9 full fills up to 250 bar (3600) in the Veteran from using the SCBA by itself.
By using the cascade, I get the pressure from 110 bar (1600psi) up to something like 2700 (average cuz sometimes all the way to nearly 3000 and sometimes only up to 2500 or so) from the SCUBA, and then use the SCBA to go from 2700 to 3600. That just about doubles my good fills, the ones where I can go all the way to 250 bar (3600 psi).
So where does the extra air come from to allow me to get twice as many FULL fills in the Veteran from the same 4100 fill in the SCBA? From the SCUBA of course. So, when the SCUBA pressure gets down to something like 2400-2500, I'll use a dead head in the female foster that usually connects to the guns (highest point in the pic again) to transfer air from the SCBA to the SCUBA to get it back up as high as possible. I then take the SCBA out to my little tool room and hook it up to the Shoebox. In this way, I only have to move the heavier SCUBA when I take it to the long weekend field target shoots over the summer and want lots of air out in the national forest.
Some caveats to this whole concept:
So, if you find yourself where I was, having a SCUBA in your possession but having progressed in the hobby to needing higher pressure fills, don't completely discount that old SCUBA. It can still be quite useful.
So, my first couple PCPs were all either purchased with low pressure in mind, or were tuned to optimize low fill pressures. I have stated on here in the past that SCUBAs should not be over looked by airgunners. With that in mind, my first tank purchase was an 80cf SCUBA tank. Which is quite a bit of air, albeit low pressure air. For guns that only fill to 2100psi, 1600psi, and 1450 psi (my first three PCPs), that SCUBA is more than sufficient and offered a lot of shooting per fill. Well, my needs have changed and I now have 2 PCPs that need higher fill pressures, one to 250 bar, and the other to about 300 bar. 3000 psi is a little over 200 bar so a regular SCUBA tank cant utilize the upper end of the fill pressures of a regulated gun. End result of filling 250 and 300 bar PCPS with a 200 bar SCUBA? drastically reduced shot counts because the low pressure tank simply can't fill to high pressures.
That all lead me to purchase a 60 min Drager from Ebay, as well as one of the $40 fill stations, also from Ebay. I had heard of cascade systems used by dive shops and did some research. My searching led me to this product:
https://airtanksplus.com/product/tman-pcp-tee-block-air-splitter-female-foster-to-2-male-foster-fittings/ basically a Y that allows me to hook up the fill station from the SCUBA with the fill station from the SCBA to create a home cascade system.
Here is a picture of my actual setup:
Close up of the TMAN;
The black tank is the 80cf SCUBA with a Brancato fill station (rated to 4000psi). The blue tank is the 60 min SCBA with the ebay fill station (thicker hose). The red Y above and to the right is the TMAN splitter. Both female ends of the fill stations are hooked into the male inputs of the splitter. The highest point is the female foster that gets attached to the guns during filling. The procedure is to open the valve on the black tank (max 3000psi) and get the guns reservoir as high as possible with the low pressure tank. Then I close the black tank valve, still leaving everything pressured. I then open the valve on the blue tank and bring the pressure in the gun up to where I would like it to be. I then close the valve on the blue tank and vent the system using the better vent on the Brancato fill station.
I only fill the SCBA to 4200 to make things easier on all fittings and my Shoebox. Yes, I'm over the Brancato fill station rating by a little.
The theory with all of this was somewhat difficult for me to comprehend, so an example might help (or maybe I'm the only slow one). I usually refill my Veteran when it gets down around 110 bar (about 1600psi). If I only used the SCBA tank, the pressure in that tank would go down by a little more than 55psi, every time I filled the gun. That means I would only get about 9 full fills up to 250 bar (3600) in the Veteran from using the SCBA by itself.
By using the cascade, I get the pressure from 110 bar (1600psi) up to something like 2700 (average cuz sometimes all the way to nearly 3000 and sometimes only up to 2500 or so) from the SCUBA, and then use the SCBA to go from 2700 to 3600. That just about doubles my good fills, the ones where I can go all the way to 250 bar (3600 psi).
So where does the extra air come from to allow me to get twice as many FULL fills in the Veteran from the same 4100 fill in the SCBA? From the SCUBA of course. So, when the SCUBA pressure gets down to something like 2400-2500, I'll use a dead head in the female foster that usually connects to the guns (highest point in the pic again) to transfer air from the SCBA to the SCUBA to get it back up as high as possible. I then take the SCBA out to my little tool room and hook it up to the Shoebox. In this way, I only have to move the heavier SCUBA when I take it to the long weekend field target shoots over the summer and want lots of air out in the national forest.
Some caveats to this whole concept:
- yes, I am wasting a little bit more air in the extra lines with each fill
- yes, air consumption is air consumption (the argument here is that I have more air on tap at any given moment and get more high pressure fills/each full 4200psi SCBA in a gun by using the two tanks in this way than I would if only using the SCBA)
- yes, I am a little over the 4000psi rating of the Brancato fill station.
- no, I do not have any affiliation with airtanksplus/stikman/tman/etc.
- yes, there is possibly an easier/cheaper way to connect multiple tanks together (I was leary of trying to piece together something myself from random fittings)
So, if you find yourself where I was, having a SCUBA in your possession but having progressed in the hobby to needing higher pressure fills, don't completely discount that old SCUBA. It can still be quite useful.
