A DRV regulates two separate parameters simultaneously, such as pressure and flow rate. It integrates:

• Pressure regulation chamber – maintains target outlet pressure.
• Flow regulation element – controls flow rate independently.

Example: A plumbing double-regulating valve may first limit inlet pressure to 3 bar and then maintain a constant 8 L/min flow.

Why use a DRV instead of a single valve?

There are 3 key reasons:

• Improved safety – prevents over‑pressure and over‑flow simultaneously.
• System stability – stabilizes downstream systems (heating, irrigation).
• Efficiency – avoids need for two separate valves and additional piping.

Example: Fire‑suppression systems use DRVs to protect pipelines and ensure consistent spray.

For applications needing dynamic flow control, a PICV valve (Pressure Independent Control Valve) can be used alongside or in place of a DRV, depending on system design.

How does a DRV work internally?

Operation involves 4 sequential steps:

• Sensing inlet pressure via diaphragm/analog sensor.
• Adjusting pressure spool to maintain outlet target.
• Measuring flow via office and differential pressure.
• Modulating flow spool to regulate to set rate.

The spools act independently but are hydraulically linked under feedback control.

What are common types of DRVs?

DRV designs vary by application:

• Hydraulic DRVs – use pilot oil control; ideal for heavy machinery.
• Pneumatic DRVs – suitable for low-pressure air systems.
• Digital/electronic DRVs – incorporate sensors and microcontrollers.

Example: Digital DRVs enable remote adjustment and monitoring.

Where are DRVs commonly used?

Devices and industries include:

• Boiler feed systems – maintain feedwater pressure and flow.
• HVAC units – balance chilled/hot water circuits.
• Fuel dispensing – control both fuel pressure and delivery flow.
• In HVAC applications, DRVs are often installed alongside commissioning valves to allow precise flow setting and system balancing.

How do you size and install a DRV correctly?

Sizing steps:

• Identify max inlet pressure and required outlet flow.
• Choose valve with suitable pressure drop rating.
• Verify material and connection type (NPT, BSP)

Installation tips:

• Use filter upstream to protect valve internals.
• Add isolation valves to simplify maintenance.
• Include pressure gauges before and after the valve.

What maintenance is required for a DRV?

Maintenance schedule:

• Every 6 months – clean internal filters and strainers.
• Annually – inspect diaphragms and spool seals for wear.
• After 2 years – pressure‑test and recalibrate to maintain ±3 % accuracy.
• As needed – replace seal kit per manufacturer guidelines.

How does a DRV differ from separate pressure and flow controllers?

• A single valve only regulates one parameter.
• Two valves require additional plumbing and can interfere.
• A DRV offers compact, integrated regulation, reducing installation complexity.

How does understanding a DRV improve system design?

Understanding a DRV supports:

• Optimized equipment selection – fewer valves, simpler piping.
• Cost efficiency – lower component and labor costs.
• Reliability and performance – integrated control ensures stable operation.

How can you apply DRV knowledge to real‑world projects?

• Analyze system requirements – pressure and flow.
• Select DRV with correct specs (pressure, flow, connection).
• Plan installation layout – ensure room for maintenance.
• Monitor operation – install gauges and test performance regularly.
• Document maintenance – track calibrations and part replacements.

Final Takeaway

A DRV (double regulating valve) is a compact, efficient solution that simultaneously controls pressure and flow, delivering consistent performance and reliability. Understanding its operation helps engineers design safer, more efficient fluid systems with reduced cost and complexity.