Product Overview
Pneumatic butterfly valves are commonly used pneumatic valves for pipeline flow control and shut-off. They are widely applied in petroleum, chemical, metallurgy, hydropower, and other industries.
The valve is controlled by a positioner, solenoid valve, or other devices. Dry, lubricated compressed air enters the cylinder of the pneumatic actuator, driving the actuator to rotate as required and enabling the butterfly valve to open, close, or regulate flow.
An intelligent positioner can also be connected to a fieldbus system to monitor valve status and provide diagnostics.
Pneumatic butterfly valves feature flexible operation, fast switching, reliable safety, and long service life, making them widely used control valves in industrial pipelines.
Installation Requirements
1. Pre-Installation Inspection
Before installation, the pneumatic butterfly valve must undergo a visual inspection, and its nameplate must comply with current national standards.
For valves with an operating pressure greater than 1.0 MPa and valves used for shut-off on main pipelines, strength and tightness tests must be conducted before installation.
During the strength test, the test pressure shall be 1.5 times the nominal pressure, with a duration of at least 5 minutes. The valve is considered qualified if there is no leakage from the valve body, bonnet, or packing.
2. Installation Position
The installation position, height, and inlet/outlet direction must meet the design requirements.
The direction of fluid flow must match the arrow marked on the valve body, and all connections must be secure and tightly sealed.
Installation Quality Inspection
1. Valves installed on process pipelines and equipment must have product qualification certificates.
2. Check whether the valve model, specifications, and pressure rating comply with the drawing requirements.
3. Check the valve housing for cracks, air holes, sand holes, and other defects, and verify that the installation direction meets process requirements.
4. Check whether the valve operates smoothly and whether the opening and closing movements are flexible. For valves equipped with actuators, the actuator must operate flexibly and reliably.
5. During pressure testing, there must be no leakage. Butterfly valves with a nominal diameter of DN150 or smaller are qualified if no leakage occurs during a 5-minute pressure test. Butterfly valves with a nominal diameter greater than DN150 are qualified if no leakage occurs during a 10-minute pressure test.
For pneumatic butterfly valves equipped with actuators, such as electric, pneumatic, or hydraulic actuators, tightness tests must be performed using the actuator in addition to manual operation. The valve must be tested and adjusted until it meets the requirements.
