Ever wonder what's inside of the regulated valve that is attached to the HPA tank you use? I did too and have been looking for an inexpensive deal on one for quite some time so I could rip it apart and see what makes it tick. Such is the curse of the habitual tinkerer. I found a great deal on one and also found out that taking it apart was definitely no picnic. I was even fortunate enough to find the exact same reg that is on my personal tank which is a high pressure Crossfire 68/4500ci hpa tank. I'll give you a look at what's inside, the order that the parts were taken out and give a short description of the picnic I had taking it apart.

NOTE: It is not suggested to remove, disassemble, modify or repair a high pressure air(HPA) tank unless you are a qualified air smith. Doing so can cause permanent or lethal damage to yourself or others if performed in an incorrect manner. This article was written as a study and is no way an incentive for the unqualified to take it upon themselves to disassemble or repair a high pressure tank on their own. Always seek out the manufacturer or a professional when repairs are needed for such a possible potentially dangerous piece of paintball equipment.

Prior To Disassembling The Regulated Valve

The normal procedure would have been to remove the tank from the regulated valve but since I bought the reg/valve already removed, this step was omitted. This procedure would have been the same as in the anti-siphon installation article but with a bit more caution with a fiber wrapped tank since they are a bit easier to deform than an all aluminum or steel tank. The gauge, burst disks and fill nipple were next for removal. I breezed through that as well since they were already loosened. They needed to be removed before you can remove the tank from the regulated valve so whoever did that had already performed this task.

The Disassembly

Now for the fun part......I had a pan of boiled water handy so I could submerge the stainless portion of the reg body into it to loosen up the Loctite on the threads of both parts to be separated. This is the safest way to heat it so not to melt any rubber o-ring seals inside of the reg. I left it in the boiled water until the tank threads got too hot to hold onto by hand. About 2 - 3 minutes.

I then quickly chucked the hex portion where the gauge, burst disks and fill nipple were attached in a vice making sure it was wrapped in some tire tube rubber so not to mar the anodized surface. At first I tried using a rubber strap wrench on the stainless body of the reg but it wasn't working because the stainless surface was just too slick for the strap to get any sort of grab onto it. I'm sure there is a proper tool but I didn't have it so I just got my trusty Craftsman vice grips out and latched them on. They marred the surface of the stainless steel a bit but this was just a curious tinker project and I didn't really care. It seemed impossible for me to turn the parts apart so I needed to think of something else. A bit of leverage was needed so I scrounged around and found a pipe that would fit over the end of the vice grip handles. By this time I needed to heat it once again then chuck it back in the vice. With a little persuasion I finally broke the bond of the threads and unscrewed the parts from each other. It seems that Crossfire really didn't want to make it too easy to separate these parts and rightfully so since doing the wrong things to them can render them a potential hazard when attached to a tank filled to 4500psi.

The first things that came out of the body was the thick steel compression spring and an aluminum piston with o-ring seal. On the tank end of the piston was a smaller o-ring attached to the smallest boss on the end. Looking in the stainless portion of the reg/valve I removed a pin valve with a plastic seal attached and small spring that is a bit different than the ones installed in a C02 tank valve. All that was left to remove from the parts was a small square piece of plastic in the aluminum tank portion of the reg/valve.

Mysteries Solved

Well, there you have it....curiosity satisfied. This is of course a high pressure fixed regulator HPA valve. I would suspect the only difference in the low pressure version would be a different compression spring. Now on to finding an inexpensive adjustable regulated HPA bottle valve to rip apart to see what makes it tick. I did find some answers to other questions in my mind while investigating this component as well listed below.

I often wondered why there are 2 burst disks on HPA tanks.  With investigation I found that 1 is for the tank portion and 1 is for the regulator portion of the assembly. The through hole passages are drilled on an angle to accomplish this. The disks for this particular 4500psi tank are rated at, 7000psi burst rate directly to the bottle and the one that goes to the regulator is at a 1800psi burst rate.

I always thought that the fill nipple had a spring loaded valve that closed it after the fill line was removed. I found that the one equipped with this particular bottle is a simple cylinder that has a flanged o-ring on it inside the steel quick disconnect body. What closes it is the back pressure from the tank. Simple but effective.

Technical Information