1. First weld the flange to the pipe and cool to ambient temperature before installing the valve to the flange. Otherwise, the high temperature generated by welding will affect the performance of the resilient valve seat.
2. The edges of the welded flange must be machined with a lathe until the surface is smooth to avoid injury to the resilient seat during valve installation. The flange surface must be completely undamaged and undeformed, and all dirt, dust and foreign matter must be removed to avoid liquid leakage from the valve and flange interface.
3. Clean the flange and pipe cavity to thoroughly remove spatter from welding, flaking scale and other foreign matter left behind.
4. When installing piping between valves, precise centering of the upstream and downstream piping is essential for trouble-free operation. The inaccurate centering shown in Figure 1 must be avoided.
5. Install the valve with the locating bolts below the pipe at the same height for support and adjust the distance between the flanges until the two sides of the valve body are about 6-10 mm apart. Remember that here the valve can only be opened from the closed position to the 10 ° position.
6. Insert the two bolts into the lower side guide rod of the valve and then install them carefully so that the flange surface does not damage the resilient valve seat. (See Figure 2)
7. Then place the other two bolts into the guide rod above the valve to ensure accurate centering between the pipe and the valve.
8. Open the valve three times to check for misalignment between the contact of the valve plate and the flange.
9. Remove the locating bolts and place all bolts around the valve body for alternate diagonal tightening (see Figure 3 Figure 4) until the flange touches the valve body. Refer to the table below for recommended torque values.
10. Provide a support for the valve when installing the actuator to avoid twisting of the valve neck and to reduce friction between the valve and the piping.
11. Do not step on the valve neck or valve handwheel.
12. Do not install DN350 or larger valves upside down.
13. Do not install butterfly valves directly on check valves or pumps, which may cause damage when contacting the valve plate.
14. Do not install valves on the downstream side of elbows and tapering pipes, or calibrate valves when the flow rate changes. When this occurs, it is recommended that the valve be installed at a distance of approximately 10 times the nominal diameter of the valve.
15. Installation of the valve needs to take into account which valve plate will be subjected to the flow rate and pressure in the process of conveying liquid.
