Seraphina Tank Proof Test - June 26th, 2026
The assembled Seraphina tank was hydrostatically proof-tested against a calculated maximum expected operating pressure of 1,124.24 psi. The proof target was 1.2 times MEOP, rounded to 1,350 psi.
Pressure sequence
The tank was first held at 100, 500 and 1,000 psi for approximately five minutes at each level. Fittings, plugs, seals and threaded connections were inspected at every hold. Minor NPT-plug leaks found during the 100 psi check were located with soapy water and a live camera view of the bottom bulkhead, then corrected.
The live test log called the 550 and 1,000 psi checks good, then recorded that the pump was maintaining pressure against aggressive leakage while the tank was being raised beyond 1,000 psi. A reported ping prompted another inspection and soap was applied to the top of the tank. The archive does not state the exact repair between that live observation and the final hold.
The formal test report states that the tank then held 1,350 psi for 18 minutes. The required 15-minute hold was extended by three minutes for fill, abort and timing allowance. The final hold had no pressure loss, visible deformation or leakage.
Post-test inspection
The tank was depressurized and disassembled. The cylinder, O-ring, retaining rings, bolts, nuts and both bulkheads showed no permanent deformation, damage or other abnormality.
