System description

Pressure test HPS.pdf

Return line pressure gauge, check valve V-57 and flow switch are on the floor next to the vacuum flange.

Chiller is located on level 2, beam right. Temperature measurement and setpoint on a digital display at the chiller; interlock circuit will also be next to the chiller. Current operating pressure is 50 psig at the chiller outlet.

System diagram

HPS Cooling.pdf

Errata and additions

• Diagram places pressure relief valves V-64 and V-67 on the inlet and return purge lines. They are actually on the inlets of the two tracker halves (before valves V-55 and V-66).
• Solenoid valve (not numbered) is currently not part of the system.
• Length of lines from the chiller is ~10 m, not ~3 m as marked.
• Pressure gauges, for local readout: two at the inlets to the tracker halves (before valves V-55 and V-66), one on the common return line (before check valve V-57), two on the inlet and outlet of the chiller.

Notes on operation (from Marco)

• Never leave the vacuum chamber manifold sealed off from the rest of the system during temperature changes; each tracker half must have some vent path to allow for thermal expansion of the coolant. In other words, if you shut off the chiller, you must let the tracker warm up to ambient temperature before you close valves.
• Pressure relief valves are set to 65 psig. Pressure on inlet side of the tracker must never be above 60 psig; to be conservative, never let pressure at chiller output exceed 60 psig (this provides more than 10 psi margin).
• Recommended procedure for draining coolant from system is to close V-87 and V-88, connect a gas bottle to one of the purge valves, put a bucket under the other purge valve, open purge valves V-69 and V-63, and flush the coolant out into the bucket. The pump shown in the diagram is not required. When restarting the system, no particular care is needed to avoid air bubbles in the system; just connect the chiller and go.