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Pneumatic Diaphragm Regulating Valve

Pneumatic Diaphragm Regulating Valve

Valve Body Structure (Two Main Parts)

1. Upper Part: Pneumatic Diaphragm Actuator (Diaphragm Head)

• Diaphragm: Rubber/Fluororubber, generates thrust under pressure

• Spring: Resets and balances air pressure (multi-spring structure is more compact)

• Push Rod: Connects the diaphragm and valve stem, transmits linear motion

• Bracket: Connects the valve body

2. Lower Part: Valve Body Adjustment Mechanism

• Valve Body: WCB, 304, 316, etc.

• Valve Core/Seat: Controls the flow area

• Valve Stem/Packaging: Seals against leakage

• Common Valve Body Types:

◦ Single-seat valve: Low leakage, high precision

◦ Double-seat valve: Low unbalanced force, suitable for large pressure differentials

◦ Sleeve valve: Stable, noise-reducing, erosion-resistant

◦ Angle valve: Anti-clogging, suitable for slurries and crystallizing media
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Product Description

Working Principle

 

1. Signal Input: The control system (DCS/PLC) outputs a 4~20mA electrical signal.

2. Positioner Conversion: The valve positioner converts the electrical signal into 0.02~0.10MPa air pressure.

3. Diaphragm Drive: Air pressure pushes the diaphragm, compresses the spring, and drives the push rod/valve stem/valve core to move.

4. Flow Regulation: The valve core displacement changes the gap with the valve seat, controlling the medium flow rate.

5. Force Balance: Air pressure thrust = spring reaction force + medium force, stabilizing the valve position.

 

Key Characteristics

 

1. Operating Mode (Safety Mode)

• Air-to-Open (FC): Opens with air pressure, closes without air pressure (preferred for fuels and hazardous media)

• Air-to-Close (FO): Closes with air pressure, opens without air pressure (preferred for cooling water and venting)

2. Flow Characteristics (Determined by Valve Core Shape)

• Linearity: Stroke is proportional to flow rate (stable load)

• Equal percentage: Small opening, slow adjustment; large opening, fast adjustment (most commonly used, suitable for temperature/pressure control)

• Fast opening: Small opening, rapidly maximizes flow (on/off control)

 

Applicable operating conditions

 

• Chemical industry: Reactors, distillation columns, pipeline flow/pressure regulation

• Petroleum industry: Crude oil transportation, oil-gas separation, heating furnaces

• Power industry: Boiler feedwater, desuperheating and pressure reduction, flue gas desulfurization

• Metallurgy: Hot blast stoves, water treatment, blast furnace gas

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Related Products

Angle Control Valve

Angle Control Valve

Structural Features

• Right-angle valve body with 90° inlet and outlet, ensuring simple and smooth media flow.

• Valve core structure: Single-seat plunger type valve core, providing high adjustment accuracy.

• Flow path: Straight-through with low resistance, less prone to clogging and material accumulation.

• Internal components: Valve core and seat can be hardened for wear resistance and erosion resistance.

• Actuator: Commonly pneumatic diaphragm type, but electric actuators are also available.

Working Principle
Fluid flows in from the bottom, and the valve core moves up and down to change the flow area, achieving flow and pressure regulation.

Because the flow path has a right-angle turn, the media directly scours the bottom of the valve core, minimizing erosion on the valve seat and ensuring good stability.

Pneumatic Diaphragm Regulating Valve

Pneumatic Diaphragm Regulating Valve

Valve Body Structure (Two Main Parts)

1. Upper Part: Pneumatic Diaphragm Actuator (Diaphragm Head)

• Diaphragm: Rubber/Fluororubber, generates thrust under pressure

• Spring: Resets and balances air pressure (multi-spring structure is more compact)

• Push Rod: Connects the diaphragm and valve stem, transmits linear motion

• Bracket: Connects the valve body

2. Lower Part: Valve Body Adjustment Mechanism

• Valve Body: WCB, 304, 316, etc.

• Valve Core/Seat: Controls the flow area

• Valve Stem/Packaging: Seals against leakage

• Common Valve Body Types:

◦ Single-seat valve: Low leakage, high precision

◦ Double-seat valve: Low unbalanced force, suitable for large pressure differentials

◦ Sleeve valve: Stable, noise-reducing, erosion-resistant

◦ Angle valve: Anti-clogging, suitable for slurries and crystallizing media

Pneumatic Fluoropolymer-Lined Control Valve

Pneumatic Fluoropolymer-Lined Control Valve

Structural Components

• Pneumatic Actuator: Primarily multi-spring diaphragm type, receiving 4–20mA/pneumatic signals to drive the valve stem up and down.

• Fluorine-lined Valve Body: Carbon steel/stainless steel base, fully lined with fluoroplastic (PTFE/F4, FEP/F46, PFA) inner cavity.

• Valve Core/Seat: Metal core encased in fluoroplastic or integral fluoroplastic, soft seal, low leakage.

• Valve Stem: 316L/Hastelloy alloy, surface hardened, corrosion-resistant and wear-resistant.

• Seal: PTFE bellows + V-type PTFE packing, double protection against external leakage.

Pneumatic Regulating V-Type Ball Valve

Pneumatic Regulating V-Type Ball Valve

Working Principle

1. The ball core has a V-shaped notch, and the valve stem drives the ball to rotate 0-90°;

2. A wedge-shaped throttling channel is formed between the V-shaped notch and the valve seat. As the rotation angle changes, the flow cross-sectional area changes synchronously;

3. When paired with a pneumatic valve positioner, it receives 4-20mA analog signals to precisely control the opening degree, achieving continuous regulation of pressure, flow rate, and liquid level;

4. When closed, the V-shaped notch fits tightly against the valve seat, achieving reliable shut-off.

+86 19858780995

+86 19858780995

+86 19858780995

+86 19858780995

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