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Differential Pressure Control Valve Selection for Two-Pipe Heating Systems 3 Best Application Schemes
The main control valve product names of China Control Valve Network include:ZHJP（low temperature type）pneumatic single seat control valve,ZYH673 pneumatic knife gate valve,ZYHSY electronic control peumatic trap.
In household-metered two-pipe heating systems, thermostatic radiator valves (TRVs) are essential for utilizing "free heat" (appliances, lighting, etc.). However, these systems operate with variable flow. Without proper Differential Pressure (DP) control, high pressure drops across TRVs cause:
Acoustic Noise: Disturbs residents.
Valve Oscillation: Leading to premature wear.
System Inefficiency: High return water temperatures.
2. Analysis of 3 Application Schemes
Scheme A: Control at Building Entrance
Constraint: This is only viable if the maximum pressure at any household does not exceed 30kPa to ensure TRV stability.
Scheme B: Control at the Riser
Suitable for lower-supply/lower-return systems. The DP valve is set at the start of each riser to maintain constant pressure for that vertical loop.
Scheme C: Control at the Household Entrance (Recommended)
This is the gold standard for large systems. It isolates the household from fluctuations caused by other users or the external network. The setpoint should equal the household's design resistance (including heat meters).
3. Key Design Conclusions for Engineers
Natural Pressure Head: In design-stage hydraulic calculations, the natural pressure head can be ignored as a safety margin.
System Configuration: Both indoor and outdoor systems should adopt Reversed-Return (Heterogeneous) layouts. This minimizes the fluctuation of the pressure drop across TRVs and reduces the required pump head.
Do you still need to know or purchase the following control valve products:
In household-metered two-pipe heating systems, thermostatic radiator valves (TRVs) are essential for utilizing "free heat" (appliances, lighting, etc.). However, these systems operate with variable flow. Without proper Differential Pressure (DP) control, high pressure drops across TRVs cause:
Acoustic Noise: Disturbs residents.
Valve Oscillation: Leading to premature wear.
System Inefficiency: High return water temperatures.
2. Analysis of 3 Application Schemes
|
Scheme |
Location |
Investment Cost |
Performance |
Best Use Case |
|
A |
Building Entrance Only |
Lowest |
Poor |
Small-scale buildings with low total resistance. |
|
B |
Shared Risers |
Moderate |
Medium |
Down-feed, down-return two-pipe systems. |
|
C |
Each Household Entrance |
Highest |
Excellent |
Large-scale or luxury residential projects. |
Constraint: This is only viable if the maximum pressure at any household does not exceed 30kPa to ensure TRV stability.
Scheme B: Control at the Riser
Suitable for lower-supply/lower-return systems. The DP valve is set at the start of each riser to maintain constant pressure for that vertical loop.
Scheme C: Control at the Household Entrance (Recommended)
This is the gold standard for large systems. It isolates the household from fluctuations caused by other users or the external network. The setpoint should equal the household's design resistance (including heat meters).
3. Key Design Conclusions for Engineers
Natural Pressure Head: In design-stage hydraulic calculations, the natural pressure head can be ignored as a safety margin.
System Configuration: Both indoor and outdoor systems should adopt Reversed-Return (Heterogeneous) layouts. This minimizes the fluctuation of the pressure drop across TRVs and reduces the required pump head.
Do you still need to know or purchase the following control valve products:
2026-03-05
