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The vacuum chuck has 3mm diameter hole for the vacuum line tube (OD/ID=3mm/1.8mm). The vacuum pump at B84 EPP lab is a GAST DOA-P704-AA with max pressure of 4 bar (60 psi). The left port (looking from front) has a 3/8" barb that we intend to connect a braided firm polyurethane rubber tube (McMaster-Carr #51165K12) with ID:OD=3/8":5/8" which runs ~1.5m from below the table to the top of table. This pump vacuum tube then transitions to the short (~30cm) 3mm OD vacuum chuck tube with a shut off valve and vacuum gauge in the transition region so that vacuum on the cooling unit can be held with monitoring after pumping. Since the vacuum gauge connection are mostly SS, we also opt for SS parts: Push on hose fitting (McMaster-Carr #53515K31) with 3/8" barb for pump tube transition to 1/4" NPT followed by On/off valve (McMaster-Carr #45395K216) and 1/4" Tee (McMaster-Carr #4452K432) for vacuum gauge mount. The Tee port is compatible with Vacuum transmitter McMaster-Carr #3278N1, or an the Omega OEM devicepressure transmitter PX119-015AI, both with SS 1/4" NPT mount . The and a 0-15psi absolute pressure measurement range. This device with miniDIN 43650C connection can be read out by the Sequent Industrial Automation Raspberry Pi interface card that can supply the 24V needed pay PX119. The final connection to the vacuum chuck tube could use a nylon part with 1/16" barb and 1/4" NPT (McMaster-Carr #5153K37). Unfortunately here is no SS bodied corresponding part. The 1/16" (1.59mm) barb is a approx match to the vacuum chuck tube with ~1.8mm ID (adequate tightness to be verified).
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| Left pump port with 3/8" barb | High-Pressure Firm Polyurethane Rubber TubingID:OD=3/8":5/8" Link ~1.5 m | 316 Stainless Steel Push-on Hose Fitting for Air and Water3/8" Hose ID, 1/4 NPT Male End Link | On/off valve High-Pressure Compact 316 Stainless Steel On/Off Valvewith Lever Handle, 1/4 NPT Female x 1/4 NPT MaleLink | 1/4" Tee316 Stainless Steel Threaded Pipe FittingLow-Pressure, Tee Connector, 1/4 NPT Female | Plastic Barbed Tube Fitting for Air and WaterSwivel Adapter, for 1/16" Tube ID (1.6 mm)x 1/4 NPT Male | cern tube OD/ID=3mm/1.8mm (~30cm) |
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Dry Air
| The dry air filters were saved by Matt from BaBar, residing inside the curtained area of B84 EPP lab. House compressed air are filtered to let out through the flow meter with a max flow of 20 ft3/min. A 80ft long hard polypropylene tubing with 1/4" OD (McMaster-Carr #9349T2) takes the drive air down to the ATLAS benches. The dry air supply tube terminates at a diverting valve (no shutoff) (McMaster #45165K42) on the bench to allow the switching of the dry air between a test port and the through path to module cooling unit. The through path continues with the same type of tube to transition to the 30cm long dry air tube into the module cooling unit which is an ID/OD=1.8mm/3.0mm blue tube from CERN shipment (same as the vacuum tube). This transition uses a similar strategy as the vacuum tubes, with a pair of Aluminum low-pressure 1/4 NPT adaptor to barbed tube fitting: 1/4" barb - male NPT (with O-ring) on supply side (McMaster-Carr #5058K441); 1/16" barb and female NPT on module side (McMaster-Carr #5058K641). The initial turn on of dry air should let run for a few hours with the outlet going to the test port using the diverting valve. Check flow and humidity at the test port before flowing into the module cooling unit. Once on for operation, the dry air flow should not be turned off. From an off state, the restart should always have the few hours of initial flush first. During operations, if the dry air needs to be off at the module cooling unit, use the diverting valve to temporarily directing the air to the test port. |
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