ZMAP pneumatic diaphragm single-seat control valve
I. Product Introduction:
The ZMAP type pneumatic diaphragm single-seat control valve features a single-seat plunger-shaped valve core with top and bottom guidance. It is suitable for applications requiring strict leakage control, low pressure difference before and after the valve, and media with certain viscosity and fibrous content. For high pressure difference and large-diameter valves, it should be used in conjunction with a positioner. Single-seat valves are suitable for occasions requiring strict leakage control, low pressure difference before and after the valve, and media with certain viscosity and fibrous content; double-seat valves have the characteristics of small unbalanced force, large allowable pressure difference, and large flow capacity, making them suitable for occasions where leakage requirements are not strict; sleeve valves offer good stability, low vibration, low noise, and low sensitivity to temperature, making them suitable for occasions with large pressure differences and non-strict leakage requirements.
II. Structural Principle:
The pneumatic diaphragm bellows-sealed control valve is a modified product of pneumatic diaphragm single-seat and double-seat control valves. It consists of a pneumatic diaphragm actuator and a bellows-sealed valve. Inside the upper valve cover of the valve part, a bellows component is installed to isolate the medium from the outside while allowing the valve stem to move up and down. In addition, the upper end of the upper valve cover is still equipped with a PTFE "V"-shaped packing seal, which serves as a secondary seal in case the bellows component is damaged. A pressure gauge is also installed on the outer wall of the upper valve cover to indicate the pressure on the outer side of the bellows. If the bellows is damaged for any reason, the pressure gauge reading will increase. Principle: When the actuator air chamber receives a pneumatic signal, it pushes the diaphragm to compress the spring pressure, and drives the push rod, valve stem, and valve core to displace, thereby changing the flow area between the valve core and the valve seat, altering the flow rate to achieve the purpose of regulating process parameters.
III. Allowable Pressure Difference:
Supply Pressure | Spring Pressure | Nominal Diameter | 20 | 20 | 20 | 20 | 25 | 32 | 40 | 50 | 65 | 80 | 100 | 125 | 150 | 200 | 250 | 300 |
Valve Seat Diameter | 10 | 12 | 15 | 20 | 25 | 32 | 40 | 50 | 65 | 80 | 100 | 125 | 150 | 200 | 250 | 300 | ||
0.14 | 20-100 | Allowable Pressure Difference MPa | 5.3 | 3.7 | 2.3 | 1.3 | 0.8 | 0.5 | 0.5 | 0.3 | 0.25 | 0.2 | 0.12 | 0.12 | 0.08 | 0.05 | 0.05 | 0.035 |
0.24 | 40-200 | 6.4 | 6.4 | 5.5 | 3.1 | 1.8 | 1.2 | 1.1 | 0.7 | 0.65 | 0.45 | 0.18 | 0.18 | 0.10 | 0.10 | 0.10 | 0.07 |
IV. Main Technical Parameters of Actuator:
Model | ZHA(B)-1 | ZHA(B)-2 | ZHA(B)-3 | ZHA(B)-4 | ZHA(B)-5 | ZHA(B)-6 |
Effective Area cm² | 200 | 280 | 400 | 630 | 1000 | 1600 |
Stroke mm | 10 | 16 | 25 | 40 | 60 | 1000 |
Spring Range KPa | 20～100 (Standard); 40～200; 80～240; 20～60; 60～100 | |||||
V. Main Technical Performance Indicators:
Item | Indicator Value | |
Basic Error % | Without Positioner | ±5.0 |
With Positioner | ±1.0 | |
Hysteresis % | Without Positioner | 3.0 |
With Positioner | 1.0 | |
Dead Band % | Without Positioner | 3.0 |
With Positioner | 0.4 | |
Allowable Leakage L/h | 1×10⁻³ × Rated Valve Capacity | |
| Machinery & Equipment/Valves/Control Valves | |
