Pressure Switches 

• Used to detect the pressure of Natural Gas, LPG, Propane, Air.
• When the Gas Pressure changes the diaphragm of the Pressure receiving part detects it and operates the (SPDT) switch to ON/OFF control the external electric circuit
• Used to detect Upper or Lower Limit of pressure.
• Adjustable Pressure Set Point visible from outside
• Available ranges 1-10mBar,2.5-50mBar,30-150mBar,100-500mBar.

Valve Proving System 

• Used for checking the leakage of the first safety valve and second safety valve in a gas train.
• Microprocessor Controlled
• Automatic Valve Proving before and after heat demand and during pre-purge possible
• Proving is done by using the line pressure of the gas
• Different cycle times available depending on the valve size and distance between the 2 valves
• Clear visual indication of the test sequence and fault causes through 5 LEDs
• A normally closed vent valve can be used with the A4021 as well
• Output for external alarm signal available
• Volatile Lockout
• Remote Reset possible.