Attention should be paid to sealing direction before the installation of eccentric butterfly valve. Generally, people are accustomed to installing valves according to the flow direction of the water supply and return pipes, resulting in poor sealing performance of valves with wrong installation direction, which affects the maintenance or accident handling of the pipeline network and equipment.
Since the directional butterfly valves marks the sealing direction on the valve body, the direction of the arrow on the valve body of the two-way sealing butterfly valve refers to the main sealing direction. The arrow direction can also be understood in this way, that is, the arrow points to the drain end. So the supply and return water butterfly valve body arrows all point to the pressure relief end of the usual maintenance, and the eccentric butterfly valve will have better sealing performance with the action of one side medium pressure.
All butterfly valves shall be installed in vertical pipes as far as possible, and the valve shaft should not be installed vertically but horizontally for horizontal installation. But the valve shaft can be installed at an inclined angle of no more than 45 degrees if it cannot be installed horizontally, which can minimize the deposition of solids in the fluid at the valve.
i. Eccentric butterfly valves should generally be installed or welded under the closed state.
ii. The limit of the valve transmission has been adjusted before leaving the factory, so do not remove the transmission at will. If the transmission must be removed, the limit must be readjusted after resumption of installation, and poor adjustment will affect valve leakage and life.
iii. During butterfly valve welding, the grounding wire of the electric welding machine must be lapped on the steel pipe of the welding joint on the same side to prevent the current from passing through the valve body and burning the sealing surface.
iv. When installing the welding valve riser, water with a height of no less than 10mm should be injected above the closed valve plate. And wet cloth should be wrapped on the valve when welding valve is installed horizontally.
v. Carefully clean the dirt on the eccentric butterfly valve after installation, and carry out 2 to 3 times of complete switching test to check whether the valve can work normally.