Pneumatic flange ball valve knowledge

Aug 13, 2019

Overview of pneumatic flange ball valves:

Pneumatic flange ball valves are ball valves with pneumatic actuators. Pneumatic actuators are relatively fast to execute and do not require workers to be hands-on, saving human resources and time to a large extent. Pneumatic flange ball valves are evolved from shut-off valves. It has the same 90 degree lift action, except that the plug body is a sphere with a circular through hole or passage through its axis. The ratio of the spherical surface to the passage opening should be such that when the ball is rotated 90 degrees, the spherical surface should be entirely present at the inlet and outlet, thereby cutting off the flow.

The pneumatic flange ball valve only needs to be rotated 90 degrees and the torque can be closed tightly. The fully equal valve body cavity provides a small, straight-through flow path for the medium. Ball valves are generally considered to be the most suitable for direct opening and closing, but recent developments have designed ball valves to provide throttling and control flow. The main features of the ball valve are its compact structure, easy operation and maintenance, suitable for general working media such as water, solvent, acid and natural gas, and also suitable for medium with harsh working conditions such as oxygen, hydrogen peroxide, methane and ethylene. The ball valve body may be integral or combined.

Advantages of pneumatic flange ball valves:

The working principle of the stainless steel pneumatic ball valve is to make the valve unblocked or blocked by the rotary valve. The pneumatic ball valve switch is light in weight and small in size, and can be made into a large diameter, reliable in sealing, simple in structure, convenient in maintenance, and the sealing surface and the spherical surface are often closed, and is not easily eroded by the medium, and is widely used in various industries.

Pneumatic flange ball valves are mainly used in the pipeline to cut off quickly, distribute and change the flow direction of the medium. Pneumatic ball valve is a new type of valve widely used in recent years, which has the following advantages:

1. The fluid resistance is small, and its resistance coefficient is equal to the pipe length of the same length.

2. The structure is simple, small in size and light in weight.

3. It is close and reliable. At present, the sealing surface material of the ball valve is widely used in plastic and has good sealing performance. It has also been widely used in vacuum systems.

4. The operation is convenient, the opening and closing is rapid, and the rotation is 90° from full opening to full closing, which is convenient for long-distance control.

5. The maintenance is convenient, the pneumatic ball valve has a simple structure, and the sealing ring is generally active, and the disassembly and replacement are relatively convenient.

6. When fully open or fully closed, the sealing surface of the ball and the valve seat is isolated from the medium, and the medium does not cause erosion of the sealing surface of the valve.

7. Wide range of applications, from small to a few millimeters, up to a few meters, from high vacuum to high pressure can be applied.

Pneumatic flange ball valve Q641F working principle:

The pneumatic ball valve is a kind of valve that rotates 90° perpendicular to the axis of the channel. It adopts a new pneumatic actuator with double-acting and single-acting (spring return), rack-and-pinion transmission and O-valve structure. Reliable; large-diameter valve adopts series AW pneumatic actuator fork-type transmission, reasonable structure, large output torque, double-acting and single-acting.

Pneumatic ball valve features:

1. The pneumatic ball valve has small fluid resistance and is the smallest fluid resistance in all valves. It is quick and easy to open and close. It is powered by compressed air. It is rotated by the torque of the angular stroke output through the piston rack and the mechanical transmission stem of the gear. The ball can be quickly opened or closed or adjusted by 0~90°. The core channel is smooth and smooth, and it is difficult to deposit media. It can be used for pipelined ball. The structure is simple, the weight is light, and the sealing performance is good. It is the execution unit of the instrument in the automation control system.

2, using electric-gas valve positioner, with electric signal and compressed air as power, accept the 0-10mA DC or 4-20mA DC current signal input by the control system, the compressed air is converted into the air source pressure signal input by the regulator Output, change the rotation angle of the core, and realize the proportional adjustment action.

3, the use of electromagnetic reversing valve, valve position echo, AC220V or DC24V power supply voltage and compressed air for power, to achieve a fast two-position cut-off control of the fluid medium.

4. Pneumatic actuator adopts piston type cylinder and crank arm conversion structure, with large output torque and small volume. It adopts full sealing and waterproof design with high protection level. The cylinder block is mirror-finished, oil-free, with low friction coefficient, corrosion resistance, superior durability and reliability. All drive bearings are oil-free with boundary self-lubricating bearings to ensure that the drive shaft is not worn.

Options for pneumatic ball valve accessories:

Cut-off accessories: single electric control solenoid valve, double electric control solenoid valve, limit switch echo.

Adjustable accessories: electrical positioners, pneumatic positioners, electrical converters.

Air source treatment accessories: air filter pressure reducing valve, air source treatment triple piece.

Manual mechanism: HVSD hand mechanism

Pneumatic flange ball valve Q641F implementation standards:

1. Design and manufacture: GB12237-89, API608, API 6D, JPI 7S-48, BS5351, DIN3357.

2. Flange size: JB/T74～90 (JB74～90), GB9112～9131, HGJ44～76, SH3406, ANSI B16.5, JIS B2212～2214, NF E29-211, DIN2543.

3. Structure length: GB12221-89, ANSI B16.10, JIS B2002, NF E29-305, DIN3202.

4. Main test: JB/T 9092, API 598.

Pneumatic flange ball valve installation:

1) Remove the protective cover on both sides of the flange end and clean it with the valve fully open.

2) Before installation, the whole machine test should be carried out according to the specified signal (electricity or gas) (to prevent the use of vibration due to transportation). After passing the test, it can be installed on the line (wiring according to the electric actuator circuit diagram).

3) Before installing the pipe, the residual impurities in the pipe must be flushed and removed (these materials may damage the seat and the ball).

4) During installation, please do not use the actuator part of the valve as a lifting point for lifting to avoid damage to the actuator and accessories. .

5) This type of valve should be installed in the horizontal or vertical direction of the pipe.

6) The pipe near the installation point should not be drooped or subjected to external force. Pipe supports or supports can be used to eliminate the deviation of the pipeline.

7) After connecting with the pipe, cross-tighten the flange connection bolt with the specified torque.

Pneumatic flange ball valve operation and use:

1) Confirm that the pipeline and valve have been flushed before operation.

2) The operation of the valve is driven by the actuator input signal size to complete the rotation of the valve stem: when the forward rotation is 1/4 turn (900), the valve is closed. The valve opens when rotated 1/4 turn (900) in the opposite direction.

3) When the actuator direction indicator arrow is parallel to the pipeline, the valve is open; when the indicator arrow is perpendicular to the pipeline, the valve is closed.

Pneumatic flange ball valve repair

With a long service life and maintenance-free period, it will depend on several factors: normal working conditions, maintaining a harmonious temperature/pressure ratio, and reasonable corrosion data.

Pneumatic flange ball valve model:

Cast steel: Q641F-16C, Q641F-25C, Q641F-40C, Q614F-64C

Stainless steel: Q641F-16P, Q641F-25P, Q641F-40P, Q614F-64P

Q641F-16R, Q641F-25R, Q641F-40R, Q614F-64R