I'm glad you asked! Let me tell you about the "PowerMax" safety features
 There is no burst disk, nor is there a burst disk in the stock 2240. If the CO2 overheats in the summer sun and wants to explode there is no burst disk. However, safety measure are provider, thanks Crosman, so I took advantage of them. I'll get back to that in a second.
 The stock red-rubber seal is design to allow blow-by around 2200psi which is what I was told. The Instruction/Precaution flyer that comes with every unit I ship states it at 2000psi which is an extra precaution I chose to take. My custom seal is designed to allow blow-by around 3300psi which is less than 70% of the actual burst pressure and the maximum rated manufactured airgun hand pump pressure. I picked 3000psi as the safe operating pressure as I state in the Instruction/Precaution flyer.
 The seal is cut to a smaller ID than the valve inlet hole. This creates a cantilever over the valve inlet hole whereby any escaping air/gas can push out under the seal in the event of over-pressurization. You simlpy can't overtighten it by hand. We tried and tried and tried.
 Also as stated in the Instruction/Precaution flyer, the use of tools to install the PowerMax is a DON'T NEVER DO IT no-no.Â
 The custom seal that come with every HiPAC is designed specifically for the 2240 valve relative to its' (seal) thickness. The ID, thickness, compression strength, recovery and elastisity was all engineered by my friend Mr. Fredricks. He did the numbers, mixed the compounds, made the rubber and really made the whole thing work.
 110deg /6hrs @ 4700psi did not exceed the burst pressure on the sealed test cylinder. The photo of the actual cylinder was still shown attached to the pump @ 3000psi. That photo is somewhere on some forum, in case you missed it.
 Now, about that safety feature I mentioned. I was told about this as a safety feature by one of the guys at Crosman. He didn't treally tell me about it. I pointed it out and he said I was right so here it is.
 At the top (seal) end of the valve the rim of the cup that holds the seal is curled in. Part of the safety feature. The bottom of the cup concaves slightly towards the center hole. Part of the safety feature. This cup, as it were, pockets the seal in place around all sides and prevents the seal from blowing out of place if it (seal) fails. Having the seal remain in place even if it fails creates an obstructed release flow of the air/gas. Crosman designed this safety feature into the valve by including a pressure relief hole in the side wall of this cup. If a seal leak occurs, air/gas will leak from around/under the seal through this relief hole. If a major seal failure occurs the blown seal will remain in place preventing the air/gas from expelling at an unobstructed rate. Air/gas will leak out at a faster rate but provided the tube has not been sealed around the valve the air/gas will expell through whatever holes there are in the tube.
 Any more questions? Feel free to ask.
Note the bigger valve set screw. This was done as an alternative to drilling holes in the tube to secure the valve. Slight modifications were made to the frame to accommodate the larger screw head