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The installation of the valve and the welding of the flange
Apr 28, 2018

1, the installation of the valve

Valve installation is best fitted with rings. When installing chains, attention should be paid to protective measures for outer coating of valves. When the valve is with the support or transmission mechanism, the hoisting rope should be fixed on the valve ring, and the hoisting rope can not be placed on the transmission mechanism. The suspension or hoisting chain can not squeeze the outer parts of the valve and the extension rod so as not to damage the valve actuator, which causes the valve to be difficult to switch or switch.

2, the welding of the valve

(1) when the valve is in position, the valve should be placed in full open position when the valve is preheated and welded. Otherwise, the valve ball of the ball valve and the gate of the valve will be stained with welding slag during the welding process. When the valve is put into operation, the slag will scratch the seat seal and cause the leakage of the valve, which will cause the valve to be invalid.

(2) valves must be supported on their respective bases or separately supported.

(3) if the valve is welded, if the valve is to be rotated, grease should be filled with manual grease gun.

(4) confirm that the outlet and outlet are closed.

(5) general ball valve installation has no directivity, but attention should be paid to the position of the operation side. Some ball valves are directional when installed, and must be installed according to the arrow marks on the valve body. For example, the import and export side of the part of the ball valve in the crude oil and finished oil station of the western pipeline is sealed with two seating forms. One end uses the double piston effect seat and the other end uses the self vent seating seat. If the valve is installed in reverse, the valve will be automatically relieved and the pipe road accident will occur.

3. Requirements after the welding of the valve

(1) before the valve is tested after the welding, the grease should be injected to ensure that the sealing surface of the valve is filled with grease, and the impurities that attach to the sealing surface of the valve seat are discharged with grease.

(2) check the valve status, ensure that all external joints are locked and no loosening; confirm that the sewage outlets and outlets are locked, and prepare for the test pressure.

(3) operate the valve according to the pressure test plan so that the valve is in the required position. - three precision valve technology department