Types of Pressure Reducing Regulators and How to Choose the Right One

What is a Pressure Reducing Regulator?

A pressure reducing regulator (also referred to as pressure regulator) is a mechanical valve designed to automatically reduce a higher inlet pressure to a lower, stable outlet pressure. It works by balancing the force of a spring with the outlet pressure acting on a diaphragm or piston, allowing precise control of the pressure delivered to the system.

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Types of Pressure Reducing Regulators

1. Direct Acting Pressure Regulators

Description: This type works by directly using the outlet pressure to counteract the spring force on the diaphragm or piston. When the outlet pressure rises above the set value, the valve closes accordingly.

Features:

• Simple construction
• Fast response time
• Able to handle low to medium flow rates

Typical Applications:

• Laboratory gas systems
• Small pneumatic equipment
• Low flow gas distribution systems

Advantages: Compact, economical, easy to maintain.

2. Pilot Operated Pressure Regulators

Description: This regulator uses an additional pilot valve that controls the main valve. The pilot valve senses the outlet pressure and adjusts the position of the main valve to maintain the desired outlet pressure. This design provides more precise control over a wide flow range.

Features: Improved stability under variable flow conditions, high flow capacity, suitable for complex systems.

Typical Applications:

• Industrial gas distribution networks
• Steam pressure control
• Large HVAC systems

Benefits: Precise pressure control, suitable for high flow and high pressure systems, reduced wear.

3. Back Pressure Regulators (Pressure Maintaining Regulators)

Description: Although not technically pressure reducing regulators, back pressure regulators maintain a constant inlet pressure by relieving excess outlet pressure. They are often used in conjunction with pressure reducing regulators in complex systems.

Typical Applications:

• Maintaining pump discharge pressure
• Protecting sensitive instruments from low pressure

Note: Back pressure regulators are designed to perform opposite functions, but are essential for overall pressure control.

4. Two Stage Pressure Reducing Regulators

Description: These regulators use two pressure reducing mechanisms in series to minimize pressure fluctuations and provide a more stable outlet pressure.

Features: Greater accuracy, reduced outlet pressure pulsation.

Typical Applications:

• Medical gas supply systems
• Semiconductor manufacturing
• Precision instrumentation gas supply

Benefits: Stable supply with rapidly changing demand.

5. Automatic Relief and Non-Automatic Relief Pressure Reducing Regulators

Automatic Relief Regulators: Features a vent that allows excess pressure to be safely released downstream to the atmosphere, preventing overpressurization.

Non-Automatic Relief Regulators: Do not release pressure; used where venting is not allowed.

Applications: Self-draining types are used in systems where the outlet pressure may exceed the set point due to thermal expansion or backflow; Non-draining types in sealed or hazardous environments.

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Pressure Reducing Regulator Selection: Application Guide

• Gas Systems: Direct-acting or pilot-operated regulators are typically selected based on flow and pressure ranges. Two-stage regulators are preferred for critical applications such as medical gases.
• Steam Systems: Pilot-operated regulators and self-draining types are typically used to handle thermal fluctuations.
• Water Systems: Pressure reducing regulators are used to protect pipelines from excess pressure; self-draining types prevent damage due to thermal expansion.
• Industrial Processing: Pilot and two-stage controllers provide the precise control needed for processes.
• Residential and Commercial HVAC: For moderate requirements, direct acting controllers are often sufficient.

 

Need the Right Pressure Reducing Regulator? Get Expert Help Selecting the Ideal Regulator Engineered for Performance |

Cashco’s pressure reducing regulators are designed for precise pressure control across a wide range of industrial applications—delivering reliability, safety, and efficiency. For more information about Cashco's regulators, view all models here .

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