SafetyNet #2 - Oxyacetylene Safety Update
Flashback Arrestors
EH&S recommends that all oxyacetylene rigs be equipped with flashback arrestor devices for the best protection against accidental flashback and explosion. Check valves do not provide the same level of protection as flashback arrestors. While properly maintained check valves prevent reverse flow of gases, they may not stop a "flame front" traveling back to the regulator.
Flame arrestors provide triple protection:
- a filter that stops the flame from traveling back to the regulator;
- a check valve that stops reverse flow of gases;
- a cut-off valve that stops the flow of gases.
Flashback arrestors are a one-time cost for a set of two (one for oxygen and one for acetylene) and are permanently mounted on the oxyacetylene rig between the regulators and hoses. They can be regularly tested "in line" without disconnection. Call EH&S at 530-752-1493 for further information.
Acetylene Regulator Maximum Pressure
Acetylene line pressure that exceeds 15 psig is DANGEROUS. The pressure must never exceed 15 psig when working with university equipment.
Gas Cylinder Storage
Please refer to Safety Net #60, Compressed Gas Safety, for information on proper storage and handling of backup or empty gas cylinders.
Fire Department Notification and Permits
Supervisors are responsible for notifying the Fire Department before the start of welding/cutting operations pursuant to UC Davis P&P 390-40
. Call the Fire Department at 530-752-6317 to provide notification. Notification must be done before the start of each job, unless the work is in a permitted location where welding is routinely done.
Oxyacetylene welding operations other than routine work by Facilities Services and contractors must have a UC Davis Fire Department hazardous conditions permit. Long-term permits are granted for locations where welding is routinely done. One-time permits are granted for non-routine locations. Call the Fire Department at 530-752-1236 to obtain a permit. If you are unsure whether your procedure requires a permit, consult the Fire Prevention Specialist at 530-752-3839.
For additional information, contact your EH&S Safety Advisor, EH&S at 530-752-1493 or ehsdesk@ucdavis.edu
.
Reviewed/Revised 2/2007
JLA