What are the installation requirements of pneumatic butterfly valve
1. Before installation, check that all parts of the pneumatic butterfly valve are free of missing parts, correct models, sundries in the valve body, and blockage in the solenoid valve and silencer.
2. Place the valve and cylinder in the closed state.
3. Hit the cylinder onto the valve (the installation direction can be parallel or vertical to the valve body), and then check whether the screw hole is aligned without too much deviation. If there is a little deviation, rotate the cylinder body a little, and then tighten the screws.
4. After installation, the pneumatic butterfly valve shall be commissioned (the air supply pressure is 0.4~0.6MPa under normal conditions). During commissioning, the solenoid valve must be opened and closed manually (it can be effective only after the solenoid valve coil is de energized), and the opening and closing of the pneumatic butterfly valve shall be observed. If it is found during commissioning and operation that the valve has some difficulty at the beginning of the opening and closing process, and then it is normal, it is necessary to reduce the stroke of the cylinder (adjust the stroke adjusting screws at both ends of the cylinder a little inward at the same time, and when adjusting, it is necessary to run the valve to the open position, and then turn off and adjust the air source again) until the valve opens and closes smoothly without leakage. It should also be noted that the adjustable silencer can adjust the opening and closing speed of the valve, but it should not be too small, otherwise the valve may not act.
5. The DFA shall be kept dry before installation and shall not be stored in the open air.
6. Before installing the butterfly valve, check the pipeline to ensure that there is no welding slag and other foreign matters in the pipeline.
7. The manual opening and closing resistance of the butterfly valve body is moderate, and the torque of the butterfly valve matches the torque of the selected actuator.
8. The flange specification for butterfly valve connection is correct, and the pipe clamp flange is consistent with the butterfly valve flange standard. It is recommended to use special flange for butterfly valve, and flat welding flange is not allowed.
9. Confirm that the flange welding is correct. Do not weld the flange after the butterfly valve is installed to avoid scalding the rubber parts.
10. The installed pipe flange shall be aligned with the butterfly valve.
11. Install all flange bolts and tighten them by hand to confirm that the butterfly valve is aligned with the flange, and then carefully open and close the butterfly valve to ensure flexible opening and closing.
12. Fully open the valve, use a wrench to tighten the bolts in a diagonal sequence, without washers. Do not tighten the bolts too tightly to prevent serious deformation of the valve ring and excessive opening and closing torque.

Structure of pneumatic butterfly valve
The pipe body of pneumatic butterfly valve is composed of pipe body, pipe shoulder, pipe nozzle and pipe tail. See the figure below for its structure, specifications and dimensions. What are the techniques for judging the quality of rubber flexible joints? What are the techniques for judging the quality of rubber flexible joints
1. Medium resistance weight increase experiment: it can take samples from products, soak them in one or several selected media, weigh them after a certain temperature, and guess the type of materials according to the weight change rate and hardness change rate. For example, after soaking in 100 degree engine oil for 24 hours, the quality and hardness change rate of NBR, fluororubber, ECO and CR is very small, while the weight of NR, EPDM and SBR is more than doubled, the hardness change is very large, and the volume shrinkage is very significant.
2. Combustion method:
Take a few samples and burn them in air. Investigate the phenomenon. Generally speaking, fluorogel, CR, and CSM are self extinguishing when they are out of fire. Even if the flame is ignited, it is much smaller than that of ordinary NR and EPDM. Of course, assuming careful investigation, the combustion state, color and smell will also provide us with a lot of information. For example, when NBR/PVC adhesive is used together, the fire splashes as if there is water when there is a fire source, and it will extinguish itself when it is away from the fire. The smoke is thick and sour. It should be noted that sometimes the adhesive added with flame retardant but without halogen will also extinguish from the fire, which depends on other methods to further speculate.
3. Hot air aging test: take samples from products and put them in the aging box for aging for one day to investigate the phenomenon after aging. Gradual aging and gradual warming can be achieved. For example, CR, NR and SBR will be brittle at 150 ° C, and NBR EPDM will be elastic. When it rises to 180 degrees, ordinary NBR will be brittle; The HNBR will also be brittle at 230 degrees, and the fluorine glue and silica gel still have good elasticity.
4. Measuring specific gravity: use an electronic scale or analytical balance, accurate to 0.01g, plus a glass of water, a hair can be. Generally speaking, the proportion of fluorine glue is the largest, more than 1.8, and the proportion of CR ECO is also more than 1.3. It can be considered that these glues are significantly larger.
5. Low temperature method: take samples from products and use dry ice and alcohol to create a suitable low temperature environment. Soak the sample in a low temperature environment for 2-5 minutes, and feel the soft and hard level at the selected temperature. For example, at - 40 ℃, silica gel is relatively soft compared with fluorine gel, which is also good at high temperature and oil resistance.
After comparing the above methods, I believe you can easily grasp the different methods of rubber joints. If you purchase a suitable product, you should use it correctly. You can also learn the correct methods of rubber joints here. Please pay attention to us.