42. What are the correct steps to open a quick-close valve?

1) Establish start-up oil. The start valve (1839) is a two-position valve. In the shut-down state, the start valve is in a position that connects the start oil circuit to the return oil line, preventing the start oil from being established. At startup, rotate the start valve handwheel clockwise; under the force of the spring, the start valve moves the spool upward to another position. At this point, high-pressure oil passes through the start valve as start oil and flows from the “F” port to the upper chamber of the quick-close valve piston, pushing the piston toward the piston disk. Simultaneously, oil is sent from the “M” port to the emergency safety device to engage it. When this function is not in use, the “M” port can be blocked. (2) The quick-shut oil shut-off valve (1830) is a two-position valve. When the machine is shut down, keep the shut-off valve (1830) in a position that connects the quick-shut oil circuit to the return oil line, so that quick-shut oil cannot be established. Once the starting oil pressure is established, rotate the handwheel of the shut-off valve (1830) clockwise, and the spool moves upward to another position under the force of the spring. At this point, the quick-shut oil circuit is connected to the “G2” oil circuit, and the quick-shut oil is established. Quick-shut oil is supplied to the lower chamber of the quick-shut valve piston disk through port “E”. (3) Opening the quick-shut valve: Once the quick-shut oil is established, slowly rotate the handwheel of the start valve (1839) counterclockwise to connect the start oil with the return oil. The start oil then returns to the oil tank through the adjustable flow orifice (which is located on the intermediate plate), causing the pressure of the start oil to drop and the quick-shut valve to open gradually. The opening time of the quick-close valve can be adjusted by regulating the opening degree of the throttle orifice through the control valve (5700).

1) Rotate the quick-shut oil control valve 1839 counterclockwise to reset the quick-shut valve. 2) Rotate clockwise by 1830 to establish start-up oil pressure. (Maintain 5S) 3) Rotate clockwise by 1839 to establish the quick-shut oil pressure. (Maintain 5S) 4) Rotate counterclockwise by 1830 degrees to connect the start oil with the return oil. 5) The quick shut-off valve opens.