To prevent the occurrence of flashbacks, a __ should be installed between the regulator and the hose, and/or between the torch and the hose?

• A. Flashback arrestor
• B. Flame screen
• C. Two-way check valve
• D. Three-way check valve

Answer: (A)

Flashback arrestors are safety devices used in oxy-fuel systems to stop flame from traveling back into hoses and equipment. By installing one between the regulator and the hose or between the torch and the hose, you create a flame-quenching path that also blocks reverse gas flow, preventing a flashfront from reaching the gas source. The arrestor typically combines a flame-arresting element with a check mechanism, so the flame is cooled and extinguished while gas can still flow forward. Other options like a flame screen don’t address backflow in the supply lines, and plain check valves alone don’t reliably stop a flash traveling through the hose—so the flashback arrestor is the correct and protective choice.