An acetylene meter regulator combines a pressure regulator with a flow meter to:
 
Reduce Pressure: Lowers cylinder pressure (up to 250 PSI) to a safe working pressure (typically 0-15 PSI for acetylene due to its instability at higher pressures).
Control Flow: Delivers precise flow rates for welding or cutting, often displayed via a flow meter (Thorpe tube or dial style).
Ensure Safety: Includes check valves to prevent flashbacks and is designed specifically for acetylene to avoid corrosion or explosion risks.
 
Key Specifications
Pressure:
Cylinder pressure: Up to 250 PSI (1724 kPa).
Working pressure: Max 15 PSI (103 kPa) for safety, as acetylene becomes unstable above 15 PSI.
High-pressure gauge: Typically 0-400 PSIG to show cylinder contents.
Low-pressure gauge: 0-30 PSIG for outlet pressure to the torch.
 
Flow Rates:
Common range: 0-15 LPM or 0-40 CFH for welding/cutting.
Some models (e.g., flow meter combos) offer precise low-flow settings.
 
Connections:
Inlet: CGA-510 (standard for large acetylene cylinders), CGA-200 (for smaller “MC” cylinders), or CGA-300.
Outlet: 9/16"-18 (Type B) or hose barbs for torch compatibility.
Left-hand threads for acetylene to prevent misuse with other gases (indicated by cuts on the hexagon).
 
Materials:
Forged brass body for durability; some with zinc-aluminum housing caps.
Stainless steel diaphragms in high-purity models (e.g., for atomic absorption spectroscopy).
 
Flow Meter Types:
Thorpe Tube: Ball-in-tube for accurate LPM/CFH readings.
Dial Style: Click settings for simplicity, often compact.
 
Common Applications
Oxy-Acetylene Welding/Cutting: Regulates gas for precise flame control.
Heating: Used in industrial heating processes.
Atomic Absorption Spectroscopy: High-purity regulators with auto-shutoff at low pressure (e.g., 85 PSIG) to prevent acetone contamination.