white parker logo

The A4A outlet family of regulators include valves that control outlet pressure. Each regulator is available with an assortment of additional variations which enable one regulator to preform several functions.

The A4A outlet family of regulators are compact, heavy duty, pilot operated, and have remarkable functionality. The regulator will gradually close when downstream pressure begins to rise above the setting and will gradually open when pressure begins to fall below the setting. The regulator cannot maintain set-for pressure if uncontrolled branch pipe lines feed into the main pipeline downstream of the regulator. The valve’s purpose is to modulate flow of refrigerant gas or liquid to maintain constant downstream pressure as set-for, despite load fluctuations.

• Industrial Refrigeration
• Commercial Refrigeration

Features and Benefits:
• Pilot operated characterized Modulating Plug for precise control
• Suitable for all common refrigerants and oil
• 28bar (406psig) design pressure (MRP)
• Unique modular construction
• Flanges threaded or welded steel pipe and copper tube (copper not for ammonia)
• Interchangeable parts
• Easy to service
• Close coupled strainers, optional
• Many control variations are possible with the use of a few Modules and Kits
• Stainless Steel Diaphragm
• Chrome Plated Pilot Seat
• Manual Opening Stem

• Depending on the specific variation of this valve, the application may include, but is not limited to;
• Compressor Motor overload prevention, Hot Gas Bypass Capacity Control, limiting refrigerant pressure in a liquid line, deep vacuum prevention in booster suction, Pressure Rise prevention in suction main, Hot Gas Defrost Control


A4A0, A4A0B, A4A0BS, A4A0E, A4A0ES, A4A0M, A4A0MS, A4A0P, A4A0PS, A4A0S, A4A0Z, A4A0EP, A4A0ESX, A4A0SX, A4W0E, A4W0ES

Minimum Working Temperature (C)

-45°C or -50°C

Minimum Working Temperature (F)

-50°F or -60°F

Maximum Working Temperature (C)


Maximum Working Temperature (F)


Maximum Pressure (bar)

27.6bar or 28bar

Maximum Pressure (psig)

400psig or 406psig

Body Material

Gray Iron, Ductlie Iron, Cast Steel

Flow Coefficient (Kv)

1.0 to 310 Kv

Flow Coefficient (Cv)

1.2 to 360 Cv

Pressure Regulator Type

Please Configure Part for Pressure Regulator Type Specification

Pressure Range (bar)

5.2 to 19.3bar or 500mm Hg to 8.3bar

Pressure Range (psig)

75 to 280psig or 20″ Hg to 120bar

Port Size (mm)

20mm to 150mm

Port Size (inch)

3/4″ to 6″

Capacity Plug

Full Capacity, 50%, 35%, 17%, N/A

Pressure Set Point (bar)

1.0 to 11.4bar

Pressure Set Point (psig)

15 to 165psig

Flange Type

FPT, ODS, Socket Weld, No Flange, Weld Neck

Connection Size

None or 3/4″ to 3-1/8″

Coil Type

Please Configure Part for Coil Type Specification

Motor Type

None, Motor Assembly- 120 V 50/60 Hz~4-20 mA Standard CAM, Motor Assembly- 24V 50/60 Hz~0-135 Ohm Standard CAM, Mounting Kit- Standard CAM, N/A

Strainer Type

With Strainer or Without Strainer

Check Valve Type

None, With CK-4, N/A

Valve Material

Standard Valve Material or Meets Pressure Equipment Directive (PED)


No Plating