The design of the Ham-Let® H-911 Excess Flow Valve has been tested for Proof and Burst. Every assembled excess flow valve is tested for proper functionality.
The poppet is loaded by a spring in a normally open position as long as the system is balanced. If the system becomes unbalanced and the downstream pressure drops, the poppet moves towards the sealing area and prevents free, uncontrolled excess flow from the line. If the downstream pressure increases, the ventilation outlet ("bleeding") enables the system to balance the pressures and (with the help of the spring) to reset the system. In this situation, the poppet reverts back to Normally Open.
These excess flow valves are excellent for Automatic Safety Shutoff in a wide range of areas including:
- Fuel systems
- Toxic Media Systems
- Gas Systems
- Valued Media Systems
- Hydraulic & Pneumatic Systems