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6122
Appendix T1 Hot Work
Station Set-Up and Safe
Operating Procedures (includes
Oxygen/Fuel Safety) |
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1.0
Purpose
There are a number of inherent hazards associated with hot work operations. Appropriate work station set-up is one method to avoid hazards. This appendix outlines Jefferson Lab’s minimum requirements for station set-up and equipment maintenance.
2.0
Scope
Hot work
environments increase the risk of electrocution because clothing and equipment
become soaked with perspiration. ES&H Manual Chapter 6670
Thermal Stress provides mitigation techniques required by Jefferson Lab for
this condition.
Requirements for all compressed gases used and/or stored at Jefferson Lab are defined in ES&H Manual Chapter 6150 Gas Cylinder Safety – Storage, Movement, and Labeling. Additional requirements for hot work are listed below.
The process steps for this procedure are performed in coordination with ES&H Manual Chapter 6122 Hot Work (i.e. Welding, Cutting, Brazing, and Grinding) Safety Program.
3.0
Responsibilities
NOTE: Management authority may be delegated to a task qualified Jefferson Lab employee at the discretion of the responsible manager.
3.1 Qualified Hot Work Operator
· Prior to commencement of work:
o Ensure station set-up complies with all requirements listed below.
o Fix non-compliances.
· Have supervisor’s approval prior to use of any welding station or equipment.
· Ensure appropriate work control documents (e.g. Hot Work Permits, Operational Safety Procedures, Laser Operational Safety Procedures, and/or other Temporary Work Permits) are appropriately reviewed, approved, and signed.
4.0
Minimum Requirements
·
Hot
Work Area:
o
Non-flammable
flooring material.
o
Non-reflective,
heat resistant, shielding.
o
Adequate
ventilation (see ES&H
Manual Chapter 6122 Appendix T5 Hot Work Ventilation/Respiratory Requirements.
·
All
welding machines are isolated-output type – with no direct galvanic connection
between the AC power ground and the output terminals of the machine.
·
Hot
work bench(es) and table(s) have fireproof tops and are grounded. (If ground is in question contact the Electrical
Safety Engineer.)
·
Electrical
outlets are of adequate voltage. (If voltage is in question contact the
Electrical Safety Engineer.)
·
Nonflammable
protective covering – available.
·
All welding equipment
(e.g. torches, regulators, electrode holders, and welding machines) have:
o
Current inspection –
see ES&H Manual
Chapter 6122 Appendix T3 Inspection of Welding and Cutting Equipment.
o Appropriate labels – see ES&H Manual Chapter 6122 Appendix T4 Hot Work Area Posting Requirements.
Step 2: Work Station Equipment
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NOTE: Inspect any personal protective equipment (PPE) prior to use. In particular, DO NOT use gloves that are contaminated by grease/oil. |
· Cylinder Set-up (NOTE: If oil or grease is detected do not use.)
o Transport cylinder per ES&H Manual 6150 Gas Cylinder Safety – Storage, Movement, and Labeling.
o Group and secure your cylinders as far away from the work as possible. If they are within the “spark-zone” cover with nonflammable protective covering.
o Remove dirt from cylinder valve threads with a clean cloth.
o Crack each cylinder valve to dislodge any dirt. When cracking cylinder stand to one side.
· Regulators
o Attach and securely tighten the appropriate regulators approved for the gas and pressure of the cylinder.
o Release the tension of the adjusting screws.
o Install flashback arrestors following manufacturer’s instructions.
· Opening Cylinders
o Slowly open the oxygen cylinder completely to seal the valve packing.
o Slowly open the fuel cylinder.
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NOTE: DO NOT open acetylene cylinder valves more than 3/4 turns so cylinder may be turned off quickly. |
·
Welding
Hoses
o Inspect hoses ensure they are clean and in good repair.
§ Do not use if cut, worn, or otherwise damaged.
o Ensure hose placement is clear of walkways; falling metal, slag, or sparks. Cover if necessary to ensure their protection.
o Oxygen hose:
§ Connect the oxygen hose to the oxygen regulator and tighten.
§ Allow 3 to 5 PSIG of gas to escape for 5 to 10 seconds to clear the line.
§ Shut off oxygen flow.
o Fuel hose:
§ Connect the fuel hose to the fuel regulator and tighten.
§ Allow 3 to 5 PSIG of gas to escape for 5 to 10 seconds to clear the line.
§ Shut off fuel flow.
· Welding Torch Handle and Tip (NOTE: If oil or grease is detected do not use.)
o Remove dust or dirt from torch handle with a clean cloth.
o Connect the oxygen hose to the torch handle valve marked “oxy” and tighten securely.
o Connect the fuel hose to the torch handle valve marked “fuel” and tighten securely.
· Welding/Cutting Tip (NOTE: If oil or grease is detected do not use.)
o Ensure welding/cutting tip is the appropriate size for the job.
o Inspect cone end, coupling nut, and torch head – repair or replace if damaged.
§ Remove dirt and dust with a clean rag.
§ Ensure that there are two “O” rings on the cone end.
o Connect welding or cutting tip to the welding torch handle using hand pressure only.
·
Leak
Check
o Check
for leaks using the industry standard “soap and water” leak
test.
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If a leak is found on the cylinder
valve: Step 1:
Move the
cylinder outdoors (per ES&H Manual
Chapter 6150 Gas Cylinder Safety – Storage, Movement, and Labeling) Step 2:
Disconnect the
regulator and other equipment, Step 3: Notify the Fire Marshal. |
Step 3:
Review
Work Control Documents
·
Ensure work control documents (e.g. Hot Work
Permits, Operational Safety Procedures, Laser Operational Safety Procedures,
and/or other Temporary Work Permits) are appropriately reviewed, approved, and
signed.
·
Discuss all roles and responsibilities with Fire
Watch. Ensure these are understood and agreed upon per ES&H Manual Chapter
6900 Appendix T1 Fire Protection: Hot Work Permit
Step 4:
Don
Appropriate Personal Protective Equipment (PPE)
·
In accordance with ES&H Manual Chapter
6122 Appendix T2 Hot Work Personal Protective Equipment (PPE).
Step 5:
If
performing oxygen/fuel torch work: go to Alternate
Step 5.0: Oxygen/Fuel Torch Work)
OR
Commence Work
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Alternate Step 5: Oxygen/Fuel Torch Work Light the Torch and Adjust the Flame · Open oxygen valve on the torch handle and adjust the oxygen regulator to the desire delivery range. · Close the torch handle oxygen valve. · Open the fuel valve on the torch handle and adjust the fuel regulator to the required delivery range. · Close the torch handle fuel valve. · Hold the torch in one hand and flint striker in the other. A flint striker is the only authorized method for lighting a torch. · Open the fuel valve approximately one half turn and ignite the gas. Keep opening the fuel valve until the flame stops smoking, and then slightly reduce the fuel supply to bring the flame back to the tip. · Open the torch handle oxygen valve until desired flame level is reached. Commence Work Finish Torch Work Operations · Shut off the torch oxygen valve. · Shut off the torch fuel valve. · Close both cylinder valves. · Open the torch oxygen valve (5-10 seconds) · Close the torch oxygen valve. · Release the adjusting screw of the oxygen regulator by turning the screw to the left (counterclockwise). · Open the torch fuel valve (5-10 seconds) · Close the torch fuel valve. · Release the adjusting screw of the fuel regulator by turning the screw to the left (counterclockwise). |
5.0
References
· Victor Welding, Cutting & Heating Guide, Denton Texas, 1977 and 1991
6.0
Revision Summary
Revision 1.1 – 03/24/21 – Periodic Review; Updated ‘ESH&Q’ to ‘ES&H’; updated contact information; changed ‘Fire Protection Engineer’ to ‘Fire Marshal’ to reflect the Contact Information for Responsible Positions link; corrected/updated hyperlinks and chapter titles; other minor edits. No approval required.
Periodic Review – 03/25/16 – No changes per TPOC
Revision 1.0 – 04/14/11 – Updated to
reflect current laboratory operations
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ISSUING
AUTHORITY |
TECHNICAL
POINT-OF-CONTACT |
APPROVAL
DATE |
REVIEW DATE |
REV. |
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ES&H Division |
03/25/16 |
03/24/24 |
1.1 |
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