Strainers, Sight Glasses and Other
Automatic Non-freeze Valves: NF6
When the system is operating and steam pressure is acting inside the steam trap, the non-freeze valve remains closed.
Once steam supply has ceased and pressure within the trap falls to about 0.02MPaG, the reduced pressure acting on the internal spring causes the non-freeze valve to open.
Condensate that has accumulated in the trap is then discharged through the opening.
Once steam supply is restored, the pressure inside the trap begins to rise again. After reaching approximately 0.03MPaG, the pressure begins to act on the spring, causing the non-freeze valve to close. At pressures of 0.03MPaG and above, the valve will continue to remain shut.