SOP: Vacuum and Flow Operation (Thanks to Mike and Thomas)

Transfer the SOP from the above link:

Notes 

Unlike in XPP, the manifold does not need a pressure relief valve in CXI. The CXI chamber has a pressure relief burst disk. Due to the volume of the liquid sample reservoir, they cannot be attached to adjacent valcles. Therefore, every other valve (say, 4 and 6) should attach to a liquid sample, and the valves in between should attach to lecture bottles of gases. All tubing is ½” OD, until it adapts to 3/16” to the diffractometer.

Loading a liquid sample

  1. Separate the reservoir line from the rest of the manifold at the joint just above valve 4 or 6, whichever you use.  (Requires size 1-1/8” and 15/16”wrenches.)
  2. Bring sample reservoir to a fume hood to fill it.
  3. Open the sample reservoir by separating the lid at the ISO flange. (Requires 1/2” wrench)
  4. Add liquid sample to the reservoir.  
  5. Reattach lid of reservoir and make sure valve 4/6 is closed (to avoid spreading odor.)
  6. Reattach reservoir to manifold line.   (Requires size 1-1/8” and 15/16” wrenches.)

Initialize vacuum

  1. Ensure that any new connections are properly tightened.
  2. Close all valves in the manifold. 
  3. Open the gate valve between the backing pump and the turbo pump. (Not pictured)
  4. Turn on the backing pump.
    1. Wait for backing pump to stabilize.
    2. Open valve 3, then valves 2 & 8.
    3. Wait for backing pump to stabilize.
    4. Slowly open valve 1. → Pressure should be below the Baratron’s range.
  5. Turn on chiller for the turbo pump.
  6. Turn on the turbo pump.  
  7. Wait for turbo pump to achieve standby mode (operation at less than 10W.)

Flowing a liquid sample

  1. Re-establish vacuum:
    1. Temporarily close gate valve between the turbo pump and the backing pump.
    2. Open valve 3, then 2 and 8 to evacuate air from manifold.
    3. Close valves 2 and 8.
    4. Open valve 4/6 to evacuate head space in the reservoir.
    5. Close valve 4/6.
    6. Close valve 3.
    7. Open gate valve between the turbo pump and the backing pump.
  2. Adjust flow rate up to desired pressure:
    1. Open valve 4/6.
    2. Open valve 8.
    3. Monitor Baratron pressure while slowly opening valve 1 (needle valve.)
    4. Attempt to approach desired pressure from lower pressure (try not to overshoot.)

Flowing a gas sample

  1. Close all valves.
  2. If the manifold has not yet been cleared of the last sample:
    1. Temporarily close the gate valve between the two pumps.
    2. Open valve 3, then 2 and 8 to evacuate manifold.
    3. Open valve 1 (needle valve.)
    4. Open valve 5 or 7, whichever you are using, to evacuate gas line.
    5. Close valve 5/7.
    6. Close valve 3, then 2 and 8.
    7. Reopen gate valve.
  3. Slowly adjust regulator to achieve a pressure of a few psi (unreadably low on regulator.)
  4. Open valve 5 or 7.
  5. Open valve 8.
  6. Slowly begin to open valve 1 (needle valve) to achieve desired manifold pressure by monitoring Baratron reading.

Manifold Images

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