• Control liquid level of containers in either filling or emptying applications
• Normally closed configuration for emptying or normally open configuration for filling
• Pneumatic operation is energy efficient
• On/off reliability when desired liquid level is reached
Use liquid level controllers with any air-operated diaphragm pump found under the Positive Displacement Pumps section of the online catalog. Models 74027-00 through -25 are used with pumps with port sizes up to 1". Models 74027-30 through -50 are used with pumps with port sizes from 1-1/2" to 3". Close differential pumps turn on or off when the fluid rises 5" to 6" and wide differential pumps turn on or off when fluid rises 10" to 12".|Controllers have a sensing tube (installed in the fluid) and a valve head connected to the compressed air supply line in series with the pump. As the liquid rises in the sensing tube, air pressure within the tube increases. The increase in pressure is transmitted to a diaphragm in the valve head, activating an air pilot valve that opens or closes the main valve, turning the air supply to the pump on or off.|<b>What's included:</b> For 1/4" to 1" pump controllers, 25 ft of 1/4" Nylon tubing. For 1-1/2" to 3" pump controllers, 25 ft of 3/8" Nylon tubing.