Rocket Team is requalifying a standard, consumer off-the-shelf, pneumatic tie rod air cylinder for use with pyrotechnics.
Disassembly, Cleaning, and Reassembly
Details on disassembly, seal replacement, and reassembly can be found using the manufacturer's specification sheet.
Disassembling the piston is surprisingly difficult. After use, the black powder residue doesn't extend very far up into the bore. We theorize that this is because the reaction occurs faster than the piston rod could move up the bore. An alternative theory is that the reaction just naturally doesn't travel far up the bore.
To clean the piston, we use Ajax soap, and towels wetted with isopropanol. When replacing the seals, we use white lithium grease (per the manufacturer's recommendation) to avoid damage to the O-rings.