Our ZJHN pneumatic diaphragm double seat control valve utilizes a double-number guided structure and is equipped with a multi-spring actuating mechanism. This pneumatic diaphragm double seat control valve boasts advantages such as compact structure, light weight, sensitive operation, large valve capacity, accurate flow characteristics, and easy assembly and disassembly. It is widely used for accurately controlling process parameters of gases, liquids, steam, and other media, such as pressure, flow rate, temperature, and liquid level to maintain set values. The pneumatic diaphragm double seat control valve is particularly suitable for applications with significant pressure differences, larger permissible leakage, and less than optimal cleanliness. It is extensively used in industrial control departments of the petrochemical, chemical, metallurgical, and power plant industries, primarily for controlling gases, liquids, steam, and other media.
This series includes standard, high-temperature, bellows-sealed, and jacket-insulated types, among others. The nominal pressure ratings are PN16, 40, and 64; the valve body bore range is DN25 to 400. Suitable fluid temperatures span from -250℃ to +560℃ across various grades. Leak rates are standard III and IV. Flow characteristics are linear or percentage-based. A wide variety of specifications are available for selection.
Pneumatic Diaphragm Double Seat Control Valve - Technical Specifications
| Nominal Diameter (DN) | 20 | 25 | 32 | 40 | 50 | 65 | 80 | 100 | 125 | 150 | 200 | 250 | 300 |
|---|
| Valve Seat Diameter (DN) | 20 | 25 | 32 | 40 | 50 | 65 | 80 | 100 | 125 | 150 | 200 | 250 | 300 |
| Rated Flow Coefficient (KV) | Straight | 10 | 12.5 | 19.5 | 30.5 | 48.4 | 76 | 125 | 195 | 305 | 484 | 760 | 1000 | 1600 |
| Please wait for 100% | 8 | 11 | 17,6 | 27.5 | 44 | 69 | 110 | 176 | 275 | 440 | 690 | 900 | 1300 |
| Allowable Pressure Difference (MPa) | Nominal Pressure ≤ |
| Nominal Pressure (MPa) | 1.6、2.5、4.0、6.4、10.0 |
| Rated Stroke (mm) | 16 | 25 | 40 | 60 | 100 |
| Actuator Model | ZHA/B-22 | ZHA/B-23 | ZHA/B-34 | ZHA/B-45 | ZHA/B-56 |
| Valve cover style | Standard Type (-17～+250℃), High Temperature Type (+250～+450℃), Low Temperature Type (-40～-196℃), Bellows Sealed Type (-40～+350℃) |
| غطاء بالضغط | Bolt-tensioned |
| Sealed Packing Material | V-shaped polytetrafluoroethylene packing, V-shaped flexible graphite packing |
| Valve core style | Dual-seat piston guide valve core |
| Flow characteristics | Linearity, percentage equivalence |
Pneumatic Diaphragm Double Seat Control Valve - Actuator
| Configuration Actuator Type | ZHA/B Multi-Spring Membrane Actuator |
|---|
| Actuator Model | ZHA/B-22 | ZHA/B-23 | ZHA/B-34 | ZHA/B-45 | ZHA/B-56 |
| Effective Area (cm²) | 350 | 350 | 560 | 900 | 1400 |
| Travel Distance (mm) | 10、16 | 24 | 40 | 40、60 | 100 |
| Spring Range (KPa) | 20-100 (Standard), 20-60, 60-100, 40-200, 80-240 |
| Diaphragm Material | Nitrile rubber laminated with nylon fabric, Ethylene Propylene rubber laminated with nylon fabric |
| Supply Pressure | 140～400KPa |
| Gas Source Interface | RC1/4" |
| Ambient Temperature | -30～+70℃ |
| Available accessories | Locators, air filter-regulators, holding valves, limit switches, valve position transmitters, handwheels, etc. |
| Function form | Gas-Closed (B) — Valve opens (FO) when gas is lost; Gas-Open (K) — Valve closes (FC) when gas is lost |
Pneumatic Diaphragm Double Seat Control Valve - Performance Specifications
| Project | Untracked | Tracker equipped |
|---|
| Basic Error % | ±5.0 | ±1.0 |
| Difference Return % | 3.0 | 1.0 |
| Dead Zone % | 3.0 | 0.4 |
| Always Point Deviation % | Gas valve | Origin | ±2.5 | ±1.0 |
| Origin | ±5.0 | ±1.0 |
| Air valve | Starting Point | ±5.0 | ±1.0 |
| End Point | ±2.5 | ±1.0 |
| Rated Stroke Deviation % | ≤2.5 |
| Leakage Rate L/h | 0.01% of rated valve capacity |
| Adjustable Range: R | 30：1 |
Pneumatic Diaphragm Double Seat Control Valve - Parts Material
| Serial Number | Part Name | Parts Material |
|---|
| 1 | Base | WCB(ZG25) | CF8(304) | CF8M(316) | CF3M(316L) |
| 2 | Valve body | WCB(ZG25) | CF8(304) | CF8M(316) | CF3M(316L) |
| 3 | Gasket | PTFE, metal graphite gaskets |
| 4 | Valve seat | 304 | 304 | 316 | 316L |
| 5 | Valve Core Assembly | 304 | 304 | 316 | 316L |
| 6 | Sealed Intermediate Pad | PTFE, metallic graphite gaskets |
| 7 | Guiding sleeve | 304 | 304 | 316 | 316L |
| 8 | Valve cover | WCB(ZG25) | CF8(304) | CF8M(316) | CF3M(316L) |
| 9 | Filling Material | PTFE, flexible graphite, para-phenylene ether |
| 10 | Cap Sealing | WCB(ZG25) | CF8(304) | CF8M(316) | CF3M(316L) |
Pneumatic Diaphragm Double Seat Control Valve - Product Selection
(1) Valve Body Parameters: Nominal Bore Size, Working Pressure, Process Medium, Application, Valve Body Material, and other series of parameters.
(2) Actuator Parameters: Actuator Type, Control Method, Control Signal (4-20mA, 1-5V), Operating Mode (Air-Open, Air-Closed)
Please provide as much detail as possible regarding the above technical specifications to facilitate our production and technical staff in accurately selecting the right product for you. Should you have any questions, feel free to call us, and we will do our utmost to provide excellent service!
Related Names: ZJHN Pneumatic Diaphragm Double Seat Control Valve, Pneumatic Double Guided Control Valve, Pneumatic Control Valve
