Principles of operation
The principle upon which the 180 Solenoid Pilot Control influences the expansion
valve action is by the creation of a pressure under the valve diaphragm which is higher
than the bulb pressure. This is how it is accomplished.
The type 180 has two parts, both in the the valve body-one high pressure and one low
pressure. When the solenoid coil is energized, the plunger moves upward sealing off
the high pressure port. With the high pressure excluded from the pilot control, true
suction pressure acts on the underside of the expansion valve diaphragm through the
equalizer line and the low pressure port.
When the solenoid coil is de-energized, the low pressure port is closed, thereby closing
the equalizer line from the valve to the suction line. The high pressure port is open and
liquid line pressure is applied to the underside of the thermostatic expansion valve
This high side pressure instantly overcomes the bulb pressure and supplements the
valve spring, immediately closing the port of the expansion valve.
The type 180 Solenoid Pilot Control suitable for all refrigerants except Ammonia
The 180 Solenoid Pilot Control is applicable for CFC & HCFC as a supplementary device
Item code: S-180