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VELO-cooling. Pump pressure PT003P April December. C-side. A-side. Filters replacement action successful. VELO meeting. CO 2 pump maintenance. Planned procedure for a pump maintenance while keeping the detector cold.
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VELO-cooling Pump pressure PT003P April December C-side A-side Filters replacement action successful VELO meeting
CO2 pump maintenance • Planned procedure for a pump maintenance while keeping the detector • cold. • cool the accumulator to -40 oC, such that all liquid gets sucked • into it. • The rest of the system will be much warmer and only contain gas • at 10 bar. • close the valve at the input of the accumulator • close the 2 valves at either side of the pump, in order to isolate • this pump section from the rest of the system • open the valve at the input of the accumulator • warm-up the contents of the accumulator, such that the system gets • filled with liquid CO2 • start the cooling system with the 2 remaining pumps • perform maintenance on the isolated pump VELO meeting
TL TR TLR = hand valve = electrical valve However, ……….. VELO meeting
In the startup-procedure of the cooling system the PLC opens all electrical valves at either side of a CO2 pump, making the planned procedure impossible for the TR and TLR pumps. So Krista and Martijn had to service the TL-pump. Trick for the other two pumps: either create a service mode in the PLC or make a special connector for the valve-cable to fool the PLC. VELO meeting