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.

Flow Control

There are no posts to show