The Type 634 shutoff valve has negligible unbalance because the downstream pressure is essentially the same as the inlet pressure during normal operation.
Fracture disks are color coded to indicate their shatter pressure. This shatter pressure is non-adjustable and can only be changed if the disk is changed (Type 634 shutoff valve), or if either the disk or inlet pressure is changed (Type 634M shutoff valve). Fracture Disk Information The downstream pressure at which the fracture disk shatters depends on the unbalance between inlet and downstream pressure and can be determined from Figure 4. Optional tank valves permit easy bleeding of trapped upstream and downstream pressure prior to disassembly.
#VALVE STEAM CONTROLLER MANUAL SHUTOFF REGISTRATION#
The Type 634M shutoff valve with external registration requires a control line and is installed upstream of a pressure-reducing regulator (Figure 3). The Type 634 shutoff valve with internal registration is installed between a pressure-reducing regulator and a downstream system or equipment (Figure 2). Typical Constructions Introduction Types 634 and 634M high-pressure shutoff valves (Figure 1) serve to provide overpressure protection by containment. Types 634 and 634M High-Pressure Shutoff Valves TYPE 634M SHUTOFF VALVE WITH STANDARD PIPE PLUGS IN BODY SIDE TAPPINGS TYPE 634 SHUTOFF VALVE WITH OPTIONAL tank VALVE IN UPSTREAM BODY SIDE TAPPING Figure 1.