Electronic electric double-seat control valve
I. Introduction:
The ZDLN electronic electric double-seat control valve is composed of the 3610L series electronic electric actuator and the low-flow resistance straight-through single-seat control mechanism (single-seat type). The electric actuator has a built-in servo system, eliminating the need for an external servo amplifier. It can be controlled to operate simply by connecting an input signal and a power supply. It features small size, light weight, large flow rate, and high regulation accuracy. It is widely used in automatic control systems for industrial processes such as petroleum, chemical, metallurgy, and light industry, and is extensively applied in precisely controlling process parameters of media like gas, liquid, and steam (including pressure, flow rate, temperature, liquid level, etc.) to maintain them at specified values. It is a general-purpose control valve product that complies with IEC standards. The double-seat valve is characterized by small unbalanced force, allowable differential pressure, and large flow capacity, making it suitable for clean media applications with low leakage requirements and large differential pressure. It is widely used in industries such as power, metallurgy, chemical, petroleum, environmental protection, light industry, and equipment manufacturing.
II. Working Principle:
The ZDLN electronic electric double-seat control valve has a larger flow capacity than electric single-seat control valves of the same nominal diameter. This is because the double-seat control valve has two valve cores (upper and lower) on its valve seat. The medium flows in from the left side of the valve body, passes through the valve seat and valve cores, and flows out from the right side. Its flow capacity can be increased by 20% to 25% compared to single-seat valves. When in use, the forces exerted by the medium on the upper and lower valve cores can cancel each other out, resulting in a small unbalanced force and a large operating differential pressure. However, since the upper and lower valve cores are not easy to seal tightly at the same time, the leakage rate when closed is relatively high. Nevertheless, due to its strong flow capacity and allowable differential pressure larger than that of general control valves, it is suitable for applications with high requirements for leakage rate and large differential pressure.
III. Performance Indicators:
Performance Indicators | ||
Item | Indicator Value (with positioner) | |
Basic Error (%) | ±5.0 | |
Hysteresis (%) | 2.0 | |
Dead Band (%) | 3.0 | |
End Point Deviation (%) | ±2.5 | |
Rated Stroke Deviation (%) | ±2.5 | |
Leakage Rate (L/h) | Single-seat Type | 10⁻⁴ × Rated Capacity of Valve |
Cage Type | 10⁻³ × Rated Capacity of Valve | |
IV. Main External Dimensions and Connection Sizes:
Nominal Diameter | L | H1 | H | H2 | D | H3 | |||||||||||
Normal Temperature | Medium Temperature | ||||||||||||||||
PN6 | PN16 | PN40 | PN64 | PN6 | PN16 | PN40 | PN64 | PN6 | PN16 | PN40 | PN64 | PN40 | PN64 | ||||
20 | 187 | 194 | 194 | 206 | 45 | 52.5 | 52.5 | 62.5 | 539 | 546.5 | 546.5 | 556.5 | 696.5 | 706.5 | 205 | 225 | 100 |
25 | 184 | 197 | 197 | 210 | 50 | 57.5 | 57.5 | 67.5 | 556 | 563.5 | 563.5 | 573.5 | 713.5 | 723.5 | 260 | 225 | 130 |
40 | 222 | 235 | 235 | 251 | 65 | 72.5 | 72.5 | 82.5 | 713 | 720.5 | 720.5 | 730.5 | 890.5 | 900.5 | 260 | 225 | 158 |
50 | 254 | 267 | 267 | 286 | 70 | 80 | 80 | 87.5 | 721 | 731 | 731 | 738.5 | 901 | 908.5 | 260 | 225 | 163 |
65 | 276 | 292 | 292 | 311 | 80 | 90 | 90 | 100 | 835 | 845 | 845 | 855 | 1025 | 1035 | 370 | 310 | 194 |
80 | 298 | 317 | 337 | 337 | 92.5 | 97.5 | 97.5 | 105 | 859.5 | 864.5 | 864.5 | 872 | 1044.5 | 1052 | 370 | 310 | 203 |
| Machinery & Equipment/Valves/Control Valves | |
