Defrost Differential Pressure Regulating Valves are used on supermarket systems to allow reverse flow of refrigerant gas through the suction line and evaptor during a defrost.

2017年3月19日 · This valve is known as the defrost differential valve. For a traditional hot gas defrost system, the defrost differential valve is placed in either the discharge line (downstream from the oil separator) or in the liquid line (upstream of the liquid header).

DDR-20: All defrost differential valves are set by turning the adjusting stem located under the cap on the pilot differential valve. The adjustment range is 5 to 50 psig. The (O)LDR have a factory setting of 18 psid and the DDR-20 has a factory setting of 30 psid. Turning the stem clockwise

2009年7月17日 · Basically, the A82B valve sets a minimum discharge pressure for defrost. That would be an Electrically Wide Open valve. If you have this type of system, there needs to be a different method of generating the actual differential, …

2008年1月25日 · When a circuit goes into defrost, the DDPR de-energizes to maintain a pressure differential in the discharge line somewhere in the neighborhood of 20 psig. The reason for this is to divert as much flow as needed into the receiver via the gas bypass line (OPR).

The difference in pressure is known as the defrost differential. Several methods are used to obtain the defrost differential, either acting through the liquid line using a (O)LDR valve or through the discharge line using a DDR valve.

All defrost differential valves are set by turning the adjusting stem located under the cap on the pilot differential valve. The adjustment range is 0.3 to 3.5 bar. The (O)LDR has a factory setting of 1.2 bar and the DDR-20 has a factory setting of 2 bar.

These valves maintain a differential pressure between the defrost and the liquid headers (receiver) in supermarket systems to allow reverse flows during the defrost cycle. Differential valve and solenoid in one component; Adjustment range: 0-50 psid; Capacity at 40°F evaporator temperature, 100°F condensing, 25°F superheated return, R404A 2 ...

Parker Sporlan Type DDR and (O)LDR) differential pressure regulating valves provide a pressure differential during defrost for reverse flow to occur. These are typically used on supermarket Refrigeration systems.

defrost differential. Several methods are used to obtain the de-frost differential. The (O)LDR is designed to maintain a differential pressure between the receiver and the liquid header. Sporlan liquid line differential valves have a solenoid bypass fea-ture that allows the valve to remain full open or modulate to main-tain a differential.