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--- venting_pumping_object_box [2018/04/25 17:43]
pereira [Vent Object chamber]
+++ venting_pumping_object_box [2023/05/30 14:31]
swartzj
@@ Line 2: / Line 2: @@
 ===== Vent Object chamber =====
-Requirements: PanelMate file **S800Vac**
-  * Open **S800Vac** and go to page 01 ("Production Target Box Vacuum System sec 13")
+From the S800 Main Vacuum page, go to the Object chamber page, opening the page shown in the figure below, and make sure of the following:
-  * Verify that OBJ SCI is not biased:
+  * Before you start, make sure that the gate valves named D2341 BGV and D2303 BGV are closed and that the IG is off.
-        * Check that the detectors is unbiased in the HV module sitting in dU6
+  * The vent valve should also be closed when you begin.
-        * Notify the system of the bias-off state by selecting the "OBJ_SCI_HV CONFIRM" box and clicking "HV CONFIRM OFF"
+  * Both valves to the turbo pump should be closed and the turbo pump should be switched off.
-  * Isolate chamber by closing gate valves **I177GV** and **I190GV**
-  * [[Vacuum control|Turn off]] ion gauge **I188IG**
+The procedure is then as follows:
-  * Check box "PUMPDOWN STATUS BEAMLINE OBJECT BOX". It should read "Good vacuum"
+  - Close the valve to the roughing pump RV.
-{{:wiki:objs800vac_pumped.jpg?500|S800vac Panel Mate}}.
+  - Now you can plot the pressure at BPG to monitor the pressure before you open the vent valve.
-  * In order to begin venting process, select box "VENT STATUS" and click "BEGIN VENTING PROCEDURE"
+  - **Keep a constant eye on the pressure level** as it increases rapidly. Before it nears 800 torr, **it is imperative that you close the venting valve.** Failure to do this will result in over pressure since the chamber will continue to be filled with dry nitrogen.
-        * Box "VENT STATUS" should change from "VENT PROCEDURE STOPPED" to "WAITING FOR VENT TIMER", and then to "VENT VALVE OPEN"
+  - You can now enter and open the chamber.
-        * Turbo gate valve **I188GV** will be automatically closed
-        * Vent valve **I190VV** will be automatically opened. However, the pressure in the chamber (ass seen in **I191PG** will not change because we need to open the manual venting valve
+===== Pumping Object chamber =====
-  * Go to the S800 OBJ station and slowly open the manual valve (see figure below). You can see the pressure rising in the Granville-Phillips 275 Mini-Convectron display.
-        * When **I191PG** reads atmospheric pressure select the box "VENT STATUS" and click "STOP VENTING PROCESS"
+From S800 Vacuum Main Page, go to Object chamber page. This will open the page in the figure below.
-        * The status in the box "VENT STATUS" should display "VENT PROCEDURE STOPPED" and the vent valve **I190VV** should be automatically closed
+  * Make sure that the IG is off.
-        * Close the manual valve
+  * When you start, you should have RV closed, FV open and the TGV valve, Vent valve, as well as the gate valves named D2341 BGV and D2303 BGV all closed.
-        * You can now open the chamber
+  * Close FV and open RV to start pumping down the object chamber with the roughing pump. You can make a plot of the pressure at BPG at this point.
+  * Section D2337 will initially be red with vacuum status: 'Bad vacuum'. This must turn to yellow with status 'Poor vacuum'. Wait for the pressure reading at BPG to drop to below 100 mTorr before you close RV and open FV.
+  * The vacuum reading at FPG needs to drop to below 200 mTorr before you can safely turn on the turbo pump.
+  * After turning on the turbo pump, wait for the inner circle of the pump symbol to turn green and the pump to reach 40 000 rpm before you open the valve at TGV.
+  * When the pressure decreases to below 10-3 Torr, you should see the pressure bottom out on your BPG plot, you can turn on the IG and also plot its pressure over time. Section D2337 should turn green and the vacuum status should turn to 'Good vacuum'.
+{{ :20230525_155711.jpg?600 |The object chamber vacuum control page}}
-{{:wiki:ventingvalveobjbox.jpg?300|Venting valve}}

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