Differences

This shows you the differences between two versions of the page.

--- venting_pumping_intermediate_image_box [2024/01/11 10:09]
noji [Venting the Chamber]
+++ venting_pumping_intermediate_image_box [2024/01/12 09:37] (current)
noji [Filling and Running Detectors]
@@ Line 2: / Line 2: @@
   * [[#General information]]
   * [[#Emptying Detectors]]
+  * [[#Venting the Chamber]]
+  * [[#Evacuating the Chamber]]
   * [[#Filling and Running Detectors]]
   * [[#Troubleshooting]]
@@ Line 22: / Line 24: @@
 ===== Emptying Detectors =====
+  - Double check that the detectors have been unbiased.
   - Set “PPAC Setpoint” to 0 Torr.
-  - Click **EMPTY** on the “GHS_II-PPAC_Main” page to begin pumping out the gas quickly.
+  - Click **EMPTY** on the “GHS_II-PPAC_Main” page to open valves #3 and #4 which will allow for pumping out the gas quickly.
-  - When “PPAC Pressure” reads < 0.1 Torr, click **MAN** and then **AUTO**. This will release the remaining gas into the diagnostics box.
+  - When “PPAC Pressure” reads < 0.1 Torr, turn off IG and click **MAN** and then **AUTO**. This will open valve #6 to release the remaining gas into the diagnostics box.
   - Monitor D2340 pumping station and ensure the TMP stays on and TGV remains open. If not, contact the Vacuum Operation group.
-  - Valves #1-5 should be closed and valve #6 should remain open. From this state click PUMP to enter pump mode and leave the system in this state until it is ready to be filled.
+  - Valves #1-5 should be closed and valve #6 should remain open. From this state click **VENT** and then **PUMP** to enter pump mode and leave the system in this state until it is ready to be filled.
-    * Jorge noted on 2/12/2023 that this step did not work; he reported that when he clicked **PUMP** nothing happened. Instead, he had to “manually” enter the PV name associated with this command and changed from 0 to 1. He speculated that this was most likely due to a CS Studio problem.
 ===== Venting the Chamber =====
 From the S800 Main Vacuum page, go to the Intermediate Image - RBT_BTS32 D2430 Pumping Station page, and ensure
-  * that the gate valves **D2426 BGV** and **D2436 BGV** are closed, and that the IG is off, and
+  * that the PPACs have been unbiased,
-  * that the turbo pump gate valve TVG is closed.
+  * that this pumping station has been isolated by having the gate valves **D2426 BGV** and **D2436 BGV** closed, and that the IG has been turned off, and
+  * that the turbo pump gate valve **TVG** is closed.
+The TMP can be turned off at this time.
 To vent the chamber:
-  - Monitor **RBT_BTS32:BPG_D2430:VP_RD** and **S800_GHS:PI_D2431:V_RD_AB** in a data browser,
+  - Let the Control Room and the Vacuum Operation Group be aware as EXP alarms may occur,
-  - close **RV**, the valve to the roughing pump, and
+  - put the GHS in vent mode by clicking **VENT** (valves #5 and #6 are open),
-  - open **Vent**.
+  - monitor **RBT_BTS32:BPG_D2430:VP_RD** and **S800_GHS:PI_D2431:V_RD_AB** in a data browser,
+  - ensure that **RV**, the valve to the roughing pump, is closed, and
+  - open **Vent** valve to start venting.
 The PPAC pressure S800_GHS:PI_D2431:V_RD_AB should closely follow the chamber pressure
-RBT_BTS32:BPG_D2430:VP_RD
+RBT_BTS32:BPG_D2430:VP_RD up to about 10 Torr, which is the upper limit of the range of the gauge for S800_GHS:PI_D2431:V_RD_AB.
 ===== Evacuating the Chamber =====
-{{:wiki:iimanualvalve.jpeg|}}
+Ensure
+  * that the chamber is closed
+  * that the pressure-relief mechanism (on the north side of the chamber, see picture below) is sealing (if not, adjust the flange back in place)
+{{ :wiki:iipressurereliefmechanism.jpeg?600 |}}
+  * that the manual valve (see picture below) is closed.
+{{ :wiki:iimanualvalve.jpeg |}}
+To evacuate the chamber:
+  - double-check and make sure that the manual valve is closed,
+  - put the GHS in pump mode by clicking **PUMP** (valves #3, #5, #6 are open),
+  - close **FV** below the TMP, and
+  - open **RV**.
+  - A message window, which reads, "Roughing Valve should only be opened if Manual Valve is CLOSED. Confirm Manual Valve is CLOSED before proceeding." of the manual valve is confirmed to be closed, acknowledge the message and click "Yes". This will open **RV**.
+  - now open the manual valve slowly while watching the local display of the Pirani gauge. Open slowly such that the pressure reading (in Torr) goes down by about 1 unit per second initially. The valve needs to open more as the pressure goes further down.
+  - On the CSS window, after D2430 turns to yellow indicating that the section is in "POOR VACUUM", wait until the BPG reading to go below 100 mTorr before closing RV and opening FV.
+  - Turn on TMP, and wait until it reaches the normal rotation (~40,000 rpm).
+  - Open **TGV**.
+  - Be sure to go back to S3 and close the manual valve.
 ===== Filling and Running Detectors =====
-  - If in Vent Mode, click **PUMP** then click **RUN** to enter Run Mode.
+  - If in Vent Mode, click **PUMP** then click **RUN** to enter Run Mode. The valves #1 opens and #3 remains open (#5 and #6 will be closed, and the GHS lines will be isolated from the chamber).
   - If in Pump Mode, click **RUN** to enter Run Mode.
   - Plot and monitor IG_D2430:VP_RD while filling. Ion gauge reading will increase but should remain <1E-5 Torr when PPACs are running at full pressure.

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