Understanding Parker Sporlan pressure regulating valves

Pressure regulating valves (PRVs) are fundamental components in modern refrigeration and air conditioning systems. They ensure that evaporators operate at stable pressures, protect compressors, and help maintain consistent product temperatures. Parker Sporlan has long been recognized as a leader in this space, offering a wide range of PRV solutions tailored for both commercial and industrial applications.

Bellows (Diaphragm) PRV

Bellows or diaphragm-type PRVs are among the most straightforward regulating valves. They use a flexible diaphragm that responds directly to pressure changes inside the evaporator. When suction pressure falls below the setpoint, the valve opens; when pressure rises, it closes.

Key benefits:

• Mechanical operation with no electronics required
• Rugged and dependable design with minimal maintenance needs
• Well-suited for smaller refrigeration circuits or applications where simplicity and cost-effectiveness matter most

While they lack the fine control of pilot or electronic valves, bellows PRVs remain a dependable option for low-capacity equipment such as beverage coolers, ice machines, and single-evaporator systems.

Download the Head Pressure Control Valves Bulletin

SORIT Evaporator pressure regulators

The SORIT series is one of the Parker Sporlan solutions for evaporator pressure regulation. These valves are designed to maintain evaporator pressure above a predetermined minimum, which prevents coil freeze-up, ensures proper defrosting, and maintains consistent case or room temperatures.

Key benefits:

• Low pressure drop design: Pilot-operated models require only ~0.5 psi differential, compared to ~2 psi for direct-acting valves.
• Multi-evaporator compatibility: Enables different evaporators, operating at different temperatures, to share a common suction line.
• Defrost integration: Available solenoid stop option keeps valves open during defrost, ensuring rapid temperature recovery.
• Service-friendly features: The SORIT-PI version includes manual opening stems and interchangeable seats, simplifying commissioning and service.

Because of this versatility, SORIT valves are widely applied in supermarkets, walk-in freezers, and other facilities that require stable operation across multiple refrigeration loads.

Download the Evaporator pressure regulators Bulletin

CDS electric EPR: precision with digital control

The CDS Series Electric EPRs use a stepper motor to modulate flow with thousands of incremental steps, allowing extremely precise pressure regulation.

Performance highlights:

• Digital stepper motor actuation: 2,500–6,386 steps of resolution provide precise flow modulation.
• Low power consumption: Draws only around 4 watts, making them energy efficient.
• Flexible application: Can function as an evaporator pressure regulator, head pressure control valve, or liquid-line controller.
• Serviceability: The motor and piston cartridge can be replaced without removing the valve body.
• Integration-ready: Compatible with advanced electronic controllers, supporting remote adjustment and data logging.

For operations that require tight temperature tolerances, energy optimization, or integration with building management systems, electric EPRs are an ideal option.

Download the Electric Pressure Regulating Valves Bulletin

OLDR: Liquid Line Differential Regulator

The OLDR (Oil/Liquid Differential Regulator) is a specialized Parker Sporlan valve that plays a critical role in defrost cycles and liquid management.

The OLDR maintains a controlled pressure difference between the receiver and the liquid header during defrost. It combines the function of a differential regulator and solenoid bypass in a single body, making it highly efficient and compact.

Key features:

• Dual function: Acts as both a differential regulator and a solenoid bypass valve.
• Adjustable range: Factory set for a 5–50 psid differential.
• Normally open: When de-energized, the valve stays open; when energized, it maintains the set differential.
• Sizes available: OLDR-16 (1”) and OLDR-20 (1-5/16”).
• Application-specific: Designed for defrost systems requiring reliable differential pressure control.

The OLDR is particularly valuable in larger refrigeration systems, ensuring stable defrost operation without needing multiple components.

Download the Defrost Differential Pressure Regulating Valves Bulletin

General overview

Valve type	Operation method	Complexity	Typical use case
Bellows (Diaphragm) PRV	Direct mechanical diaphragm	Low	Small coolers, simple systems
SORIT EPR	Direct or pilot-operated	Medium	Multi-evaporator refrigeration
CDS Electric EPR	Stepper-motor driven piston	High	Digital control systems
OLDR Differential Reg.	Pilot-operated piston + solenoid mode control	Medium	Defrost and liquid line control

Conclusion

Parker Sporlan pressure regulating valves cover the full range of refrigeration needs. From the mechanical dependability of bellows PRVs, to the versatile and service-friendly SORIT regulators, to the digitally precise CDS electric valves and the rugged efficiency of pilot-operated designs, there is a solution tailored to every type of system. The key is choosing the valve that best aligns with the application’s pressure requirements, load variations, and control expectations.

These valves are available through A&C Engineering, the Sporlan distributor for the Benelux. Whether you are designing a new installation, upgrading an existing system, or looking for advice on the right product selection, we can provide both the components and the technical support you need.

For inquiries, product information, or any other questions, please feel free to contact us. We are here to help you select the right solution for reliable and efficient refrigeration control.