This document provides information on gas management and piping requirements from Rexarc, including: - Flashback arrestors are needed when mixing fuel gases with oxygen or air to prevent flashback, and can be installed at the main source, in branch piping, or outlet piping. - Piping materials depend on the gas, with acetylene requiring steel and oxygen and other gases allowing steel, brass, copper, or stainless tubing. Piping must be cleaned of grease and dirt before assembly. - There are limits on allowable gas quantities per manifold based on the gas, and manifolds for oxygen and fuel gases must be separated by at least 20 feet or a fire barrier.

1. INNOVATIVE GAS MANAGEMENT and
CONTROL SOLUTIONS – For over 85 years!
www.rexarc.com

2. FLASHBACK ARRESTORS
• FLASHBACK ARRESTOR IS NEEDED WHEN MIXING A FUEL GAS WITH
OXYGEN OR AIR TO CREATE A FLAME.
• FLASHBACK IS NEEDED WHENEVER FUEL GAS IS BEING USED IN
PERMANENT PIPING WITHIN A BUILDING
• FLASHBACK ARRESTOR CAN BE PUT AT MAIN SOURCE (OPTION A),
PUT IN BRANCH PIPING(OPTION B), OR IN OUTLET PIPING(OPTION C)
• IF FLASHBACK ARRESTOR INCOPORATES A LIQUID, THE LIQUID
LEVEL SHALL BE MAINTAINED.
INNOVATIVE GAS MANAGEMENT and CONTROL
SOLUTIONS – For over 85 years! www.rexarc.com

3. INNOVATIVE GAS MANAGEMENT and CONTROL
SOLUTIONS – For over 85 years! www.rexarc.com

4. PIPING MATERIALS AND CLEANING
• ACETYLENE PIPING SHALL BE STEEL!!!
• OXYGEN AND OTHER GASES: PIPING SHALL BE STEEL,
BRASS,COPPER PIPE OR SEAMLESS COPPER, BRASS OR
STAINLESS STEEL TUBING.
• ROPEX/KITECH PIPING IS ONLY APPROVED FOR INERT
GASES.
• FITTINGS AND LENGTHS OF PIPE TO BE EXAMINED
BEFORE ASSEMBLY AND BE FREE FROM SCALE OR DIRT.
OXYGEN PIPING SHALL BE WASHED OUT WITH A
SUITABLE SOLUTION TO REMOVE GREASE AND DIRT
THAT WILL NOT REACT WITH OXYGEN.
INNOVATIVE GAS MANAGEMENT and CONTROL
SOLUTIONS – For over 85 years! www.rexarc.com

5. ALLOWABLE GAS QUANITIES
• FUEL GAS CYLINDERS CONNECTED TO ONE MANIFOLD WITHIN A
BUILDING SHALL BE LIMITED TO 3000 FT3
• OXYGEN CYLINDERS CONNECTED TO ONE MANIFOLD WITHIN A
BUILDING SHALL BE LIMITED TO 6500 FT3
• IF MORE THAN ONE OF THE SAME MANIFOLD IS USED IN SAME
ROOM THEN THEY MUST BE SEPARTED BY 20FT.
• IF OXYGEN AND FUEL GAS MANIFOLD ARE IN SAME ROOM THEY
MUST BE SEPARATED BY 20 FT OR A BARRIER OF
NONCOMBUSTIBLE MATERIAL AT LEAST 5 FT HIGH HAVING A FIRE
BARRIER OF ½ HR.
• CANNOT HAVE VISUAL SIGHTLINE FROM OXYGEN TO FUEL GAS
CYLINDER INNOVATIVE GAS MANAGEMENT and CONTROL
SOLUTIONS – For over 85 years! www.rexarc.com

6. STATION
DROPS
• OXYGEN AND FUEL GAS DROPS ARE LIMITED TO 4
OUTLETS AFTER THE BALL VALVE AND CHECK VALVE.
• INERT GASES ARE UNLIMITED ON OUTLETS
• CGA 024, 025,034, OR B SIZE CONNECTIONS ARE
ALLOWABLE ON OUTLETS (NO CYLINDER CGA’S
ALLOWED)
• OXYGEN AND FUEL GAS STATION DROPS MUST HAVE
SHUT-OFF VALVE AND CHECK VALVE. INERT DROPS
ONLY NEED SHUT-OFF VALVE
• STATION DROPS MUST BE LABELED WITH
APPROPRIATE GAS BEING USED.
INNOVATIVE GAS MANAGEMENT and CONTROL
SOLUTIONS – For over 85 years! www.rexarc.com

7. LABELS
INNOVATIVE GAS MANAGEMENT and CONTROL
SOLUTIONS – For over 85 years! www.rexarc.com
• ALL PIPING MUST BE LABELED WITH THE APPROPRIATE
GAS
• WHEN PIPING BRANCHES OFF IN DIFFERENT
DIRECTIONS A NEW LABEL MUST BE PRESENT
• LABEL PLACEMENT MUST BE SIGHTLINE TO SIGHTLINE

8. RIGHT AND
WRONG??
• REXARC CAN ONLY ADVISE AND MANUFACTURE
ACCORDING TO THE GIVEN REGULATIONS
• ALWAYS REMEMBER THAT AUTHORITY HAVING
JURISDICTION (AHJ) SUPERSEEDS ALL WRITTEN
REGULATIONS.
INNOVATIVE GAS MANAGEMENT and CONTROL
SOLUTIONS – For over 85 years! www.rexarc.com