Areas B and C are also subjected to 4500 psi, and the seal between the drop block and the stub that goes over the regulator neck is whatever the ID of the hole in the drop block is.... If that (between B and the screws) is the same as the OD of the tube, which is 7/8", the force is 2700 lbs., so you need the screws able to hold at least 3 times that, or over 8000 lbf....If the hole is larger than 7/8", the force is greater, of course....Bob
"Marauder pistol" but you seem to be referring to the rifle sized tube (1.25"od x .095"wall) as opposed to the pistol tube (.875"odx .065" wall). I get this from your 2600lbs force @3000psi.Face "B" is seeing 4500psi, and if it's at the tube id of 1.06" that's 3969lbs force. Is it secured in some manor (other than the screw) that is not shown?Screws through into the tube will see the force determined by tube id and regulator pressure...or burst disc rating in worst case.Al
the only force applied to the screws on the end of the tube will be whatever is pushing on the "neck" of the regulator (face A).
My point remains, if the drop block is made in two pieces, and those pieces joined with three screws, and sealed by an O-ring, then the force pushing the front part of the drop block off of the stub is the area where the outside of the O-ring seals times the pressure.... Your statement that....Quotethe only force applied to the screws on the end of the tube will be whatever is pushing on the "neck" of the regulator (face A).is incorrect, and is a dangerous assumption.... In addition to what Al and I pointed out about the forces trying to tear the drop block apart, that same 4500 psi will be pushing the regulator towards the valve.... If the reg. is not pinned into the tube, or located by a tubular spacer, the 4500 psi on the outer end of it will slide it right down against the valve on filling.... pushing it out of the O-rings after a short distance, and then applying 4500 psi against the stub of the drop block's full end area.... If there is a tubular spacer locating the regulator, then that 4500 psi times the full area of the ID of the tube is transfered to the valve screws.... Too many failure points in this design, IMO....Bob