Single-Seat Pneumatic PTFE Lined Double Film Head Control Valve

Technical Specification
Design and Manufacture:GB/T4213 HG/T3704
End-to-end dimension:HG/T3704
Flange Standard:ASME/ANSI 16.5
Inspection and testing:GB/T4213 HG/T3704

Product Specification
Body Material:A216/WCB, A351/CF8,A351/CF8M,A351/CF3,A351/CF3M,LCB, A536
Trim:304,304L,316,316L
Stem:304,304L,316,316L,410,416,420
Lining Material:PFA, FEP, PTFE,PO
Bellow:PTFE
Nominal Diameter:NPS 1/2-10
Pressure Range:150lb 300lb JIS DIN
Connection Type:flange connection
Operation Method:Electric Actuator/Pneumatic film head etc.

Product description:

1.Pneumatic/electric lined single-seat control valve is the execution unit in automation instrument system; it consists of many spring film actuators/electric actuators and through-way fluorine-lined single-seat regulator. Installed on the medium pipeline and operated with other instrument to control parameters such as flow rate etc. Due to the wetted parts of valve are lined with fluorine plastic (PTFE, PFA, FEP), and the stem sealing adopts PTFE bellow and packing, it has better performance in corrosion resistance and sealing and its installation has better reliability. It??s suitable for any corrosive medium except for "molten alkali metals and fluorine element??. The lined control valves are widely used in petrochemical, electric power, metallurgy, pulp&paper and other industrial automation device.

2.Operating method: electric, pneumatic, hydraulic

3.Lining material: FEP, PFA, GXPO etc.

Structure and Operation Principle:

1.Pneumatic/electric fluorine-lined control valve is consists of lined control valve body and straight travel pneumatic spring diaphragm actuator or electric actuator.

2.Pneumatic/electric actuator is an important part of automatic control system. Pneumatic actuators (figure 1) have both direct and indirect action. When air pressure increases, the push rod stretch out the membrane room, it is called direct action. When air pressure increases, the push rod back into membrane room, it is called indirect action, together with valve body to constitute the air-to-close.
3.Figure 2 shows the working principle of positioned on electrical/pneumatic valve: when the pressure signal input into membrane room, generating pushing force to the diaphragm to compress the spring, making the push rod move to drive the stem, changing the flow area between the valve trim and seat, until the counteractive by spring keep balance with pushing force on diaphragm by signal pressure, so as to achieve the purpose of process parameters automatic adjustment.