Cylinders Replacement for Fluorine Premix (<3%F2), for Eximer Laser

Cylinders Replacement for Fluorine Premix (<3%F2), for Eximer Laser

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Cylinders replacement for Fluorine Premix (<3%F2), for Eximer Laser

Standard Operating Procedure

Be aware of the Chemical Hazards:

Corrosive and toxic gases are used as the lasing medium of the lasers. Even in small concentrations, fluorine gas can be hazardous. In addition, ozone and nitrogenous gases may be created by high-power UV pulses. Ensure that the room ventilation is working properly before operating the laser.

Check that the gas cabinet airflow monitor gauges is satisfactory before opening the window or door to the gas cabinet. The smell of fluorine (a sharp, pungent odor) indicates the laser cavity or Swagelok tubing is leaking. If you smell such an odor close up and contact EH&S. If fluorine can be smelled and the exhaust is less than the above readings, the gas cylinder could be leaking. Do not attempt to change out the cylinder if the bottle is leaking or if there is inadequate ventilation flow through the chamber.

Also wear nitrile gloves when changing the halogen filter on the laser as it is hydroscopic.

A new fill may only be performed by authorized users or qualified personnel.

When changing premix cylinders:

  1. Safety note: Always use the small access port to turn the regulator and gas cylinder off. Do not open the entire cabinet door to perform these actions. The entire cabinet door should only be opened when its time to remove the bottle from the ventilation chamber and when the new cylinder is to be inserted into the ventilation chamber

EHS has informed us of a past error in the changing procedure that they call a “lesson learned”. This lesson can be found at

Review this and discuss it with the superuser that is training you on this cylinder replacement.

There may be a special lead washer that must be used to attach regulators to fluorine cylinders. The researchers forgot to use this special washer the first time they attached the regulator. When the lead washer was properly inserted and tightened properly, there was a good seal, and no leak.

Close the gas cylinder main valve but keep the regulator open.

  1. Evacuate the halogen line under the gas flow menu: start the vacuum pump and open the vacuum line.
  2. Open the halogen line and connect it to the vacuum pump. Make sure the halogen line is completely purged by repeating this process several times.
  3. Leak some Helium gas from the cylinder with the main valve open.
  4. Now close the He gas cylinder and evacuate the accumulated gas by opening the main valve to the vacuum line.
  5. Repeat this process three times. Close the vacuum line and the pump.
  6. Leak some He gas to back fill the line for safety purposes.
  7. Once that is completed, you may close the regulator isolation valve and disconnect the regulator. Air will escape into the evacuated regulator. Now you may switch the bottles.
  8. Evacuate the halogen line as above; fill and pressurize the tubing via the regulator. Then close the gas cylinder main valve.
  9. Once the line has filled, close the regulator isolation valve as well.
  10. Let the regulator and line sit under pressure to check for leaks use soap solution. If the pressure dips significantly over time, check all regulator connections for tightness.
  11. If the regulator pressure drops significantly when the regulator isolation valve is opened and the tubing has been under pressure, the tubing could have leaks. Check all Swagelok connectors for tightness, but do not overtighten.
  12. Purge the halogen line: press V then H once while the regulator is open and the gas valve is closed, then open the gas valve to fill the regulator with premix. Set the regulator to about 55 PSI. Repeat four times.

New fill:

Only authorized personnel are allowed to perform a new fill. The authorized personnel to perform a new fill of the lasers are…

A new fill must be performed manually because premix is used.

Turn the vacuum pump on, open the vacuum valve, then open the cavity head valve to pump on the cavity until it reaches below 30 mbar pressure. Then close LH, then V, and stop the pump.

Evacuate and purge the halogen line as in step 7 above, then with the line pressurized open the halogen valve and the Laser head valve to fill the laser to the desired pressure typically 3600 mbar.

A detailed new fill procedure can be found in the laser logbook.

Leak checking:

-Follow the same procedure as a new fill, but use the much safer He purge gas to fill the cavity; 3000 mbar is adequate.

-If the pressure drops faster than 2 mbar/hour, call Lambda-Physik

Additionally, the SOP for standard gas cylinder replacement must be followed.

Date: 10/13/2009

SOP Title: Gas cylinder replacement

Principal Investigator:

Lab Phone Number:

Section 1 – Process

Replacing a non-toxic gas cylinder.

Section 2 – Hazardous Chemicals

Gases can be chemically toxic, flammable, reactive, corrosive and asphixiants.

Section 3 – Potential Hazards

New gas cylinders are under large pressure. Use care when transporting them and be sure that they are properly secured to a wall during use. Inspect the cylinder before selecting it for use in the lab and be sure that the regulator is also in good order. Large metal cylinders are heavy and can cause physical problems like crushing hands or ergonomic problems. Work carefully with gas cylinders.

Section 4 – Approvals Required

Must be approved by qualified lab member. To install or replace a gas cylinder.

Section 5 – Designated Area

At the wall anchors in (these are the lab areas where the gas cylinders are to be stored) .
New gas cylinders are picked up from the store room. Always use the cylinder dolly for safe transport of the gas cylinders.

Section 6 – Special Handling Procedures and Storage Requirements

Use the cylinder dolly with chain belt to properly transport the cylinders.
The cylinders must also be stored in such a way that they are anchored/secured to the wall of the building.
A proper anchor is formed by tethering the cylinder by chain links to the wall strut that is anchored to the wall. The cylinder must be tethered by two chains, one above the center of mass of the cylinder, the other must be below.

Section 7 – Personal Protective Equipment

Wear safety glasses, consider wearing leather or shop gloves.

Section 8 – Engineering/Ventilation Controls

Be sure that the bottles are stored in a well ventilated area such that in the event of a leak, the room air does not become oxygen deficient.

Section 9 – Spill and Accident Procedures

If there are difficulties please ask any qualified lab member for assistance. If there is an accident, seek medical attention immediately and apply first aid when necessary (but first, be sure not to put your safety at risk).

Section 10 – Waste Disposal

Empty gas cylinders are returned to the store room.

Section 11 - Decontamination

None

Section 12 – Process Steps

Process Steps / Safety Measures
To Complete the training, a pamphlet
On gas cylinder safety must be read. Please
See the lab safety officer for this
material . Or at EH&S
1) Close the main valve of the gas cylinder.
2) With a wrench, unscrew the regulator
To remove it.
3) Undo the chain that tethers the cylinder to the
wall and transfer the cylinder to the dolly to
transport it to the store room.
4) Strap the cylinder into the dolly and take it to the
physics store room.
5) Retrieve a new gas cylinder and properly
transfer and secure the cylinder to the cart and
transport it back to lab.
6) remove the cylinder from the cart and place it in
the upright position at the wall mount where the
bottle is to be securely stored.
7) Tether the bottle to the wall.
8) Unscrew the safety cap and the use a wench to
tightly screw in the gas flow regulator.
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