Process requirements for switching off pump P-2601A in the adsorption separation cycle pump system

Thread Content

1. When P-2601C is in standby mode, before switching pump P-2601A to C, the following steps must be followed: Drain the line connected to P-2601C and shut it down; activate the pressure gauge. Open the inlet valve of the standby pump P-2601C (switching from A to C means opening the two suction valves located on the side of pump A). These valves are operated by the control room staff, who first open the suction valve HS-6020 without any position control, to its full open position. Then, they slowly open the suction valve HIC-6022 by 5–10% of its maximum opening degree, in order to prevent large fluctuations in the pressure in the adsorption tower. The field operator confirms that the outlet pressure of P-2601C is above 0.8 MPa; then the control room staff opens valve HIC-6022 to 100% of its capacity, and the field operator verifies that both suction valves are fully open. The field operator reports the pressure in the adsorption tower as monitored by the control room; for the P-2601C discharge warm-up pump, the field operator opens the valve in the line that leads to the underground tank before closing the outlet valve of P-2601C, ensuring that the opening degree of this valve does not exceed 1/2. A temperature probe is used to check that the temperature in the pipeline at the pump’s outlet is at least 75°C; then the valve in the line leading to the underground tank is closed before closing the outlet valve of P-2601C. Regarding the internal operations, P-2601C has been brought to standby status; the pump will be switched off once the feed for adsorption reaches bed 15-20 (with P-2601A pumping in Zone 2) ； The operator on site opens the outlet valve of P-2601C to full open, while keeping the first-stage valve at 20% open. After reporting that the conditions for starting the pump are met, P-2601C is started. Once the motor starts, it is checked that its rotation direction is normal, that the pressure is greater than 1.8 MPa, and that the pump is operating properly. The outlet valve of pump C is then opened, while the outlet valve of pump A is closed. At this point, the operator on site monitors to ensure that the flow rate and the position of the control valves remain within normal ranges. The operator also checks the current consumption of pumps A and C. When the outlet valve of pump C is fully open and the outlet valve of P-2601A is reduced to 10% open, pump P-2601A is stopped, and its outlet valve is closed tightly. It is then confirmed that P-2601C is operating normally with a proper flow rate, after which the inlet valve of P-2601A is also closed tightly.