The NABIC 500 Series encompasses high-capacity, high-lift safety relief valves designed for overpressure protection in various systems, including unvented hot water heating, steam boilers, compressed air systems, and inert gas applications.These valves are renowned for their robust construction, versatility, and compliance with stringent industry standards.
The main difference between the models is as follows.
- 520 – Two 500's combined into one valve. Has a flanged inlet.
- 500SS – Stainless Steel Inlet nozzle and disk (still has a PTFE O-ring in the disk).
- 500ST – Stainless Steel Inlet nozzle only with hygienic clamp inlet (no longer made).
- 568 - Anti-Vacuum Valves are used to protect cylinders from collapsing due to an internal vacuum.