For use in 6448 pressure manifold, these rupture discs provide extra protection to personnel and equipment involved with static and dynamic pressurized systems. In the event of an overpressure — one that cannot be handled by the 8767-20 pressure relief valve — this disc will rupture at a predetermined burst rating: 55 psig (±3 psig) for two-piece units, 65 psig (±3 psig) for one-piece units. Manufactured from a single piece of a high-purity carbon, these discs have a PTFE coating on underside, are tamper-proof, have no springs or moving parts and mount directly in a #25 Screw thread. Simply place the FETFE o-ring (7855-734) supplied with disc, on the underside to make the seal, drop into the #25 Screw thread and hold in place using a 5844-176 adapter.