The expansion valve removes pressure from the liquid refrigerant to allow expansion or change of state from a liquid to a vapor in the evaporator. The high-pressure liquid refrigerant entering the expansion valve is quite warm. This may be verified by feeling the liquid line at its connection to the expansion valve. The liquid refrigerant leaving the expansion valve is quite cold. The orifice within the valve does not remove heat, but only reduces pres¬sure. Heat molecules contained in the liquid refrigerant are thus allowed to spread as the refrigerant moves out of the orifice. Under a greatly reduced pressure the liquid refrigerant is at its coldest as it leaves the expansion valve and enters the evaporator.

Models:

• •ATX-34006...ATX-71160 DHS
• •ATX-34006...ATX-71160 DUS
• •ATX-12220...ATX-12500 DHS
• •ATX-12220...ATX-12500 DUS
• •VPX-3402...VPX-3420 DHS
• •VPX-3402...VPX-3420 DUS

Pressure controls are for use in refrigeration and air conditioning systems to give protection against excessively low suction pressure or excessively high discharge pressure and alsoused for starting and stopping refrigeration compressors and fans on air-cooled condensers.

Models:

• •Dual Pressure Switch DNS-D304... DNS-D306...
• •Single Switch SNS-C106
• •Oil Pressure Switch ONS-C106

Solenoid valves play an important role within refrigeration and air conditioning systems, controlling the flow of refrigerants. Though their base function – turning the refrigerant flow on and off – is quite simple, this function is key to ensuring system performance. Understanding how solenoid valves work increases the likelihood that contractors will install, remove and reinstall valves correctly, ensuring optimum system performance and protection.

Models:

• •SEV-502 BXF 1/4'' 110V/220V
• •SEV-603 BXF 3/8'' 110V/220V