Acetylene Safety Guard or ASG is a safety device for installation in an acetylene gas supply

system. When installed correctly, it safeguards both the high-pressure (manifold header side)

and the low-pressure section (distribution lines) of the acetylene supply system against the

exceeding of predefined response pressure. The ASG thus prevents combustible and toxic gases


The ASG is equipped with an automatic shut-off valve controlled from the high-pressure and the

low pressure side. This valve closes if one of the predefined response pressures is exceeded,

thus interrupting the gas supply in the high-pressure area. A display element indicates when the

shut-off valve is closed. The valve remains closed even if the pressures within the gas supply

system fall below the response pressures of the ASG again. The shut-off valve can only be

opened and the ASG enabled via a manually operated bleed screw. The gas supply system can

then be operated in normal mode again.

Salient features

  • ASG as per EN ISO 14114 for permanent and secure monitoring of the inlet and outlet pressures.
  • Successful type test according to EN ISO 15615 incl. Acetylene decomposition test by BAM (German Federal Institute for Material Research and Testing).
  • Immediate closure of the Acetylene supply as soon as a pressure exceeds its set point.
  • Resettable shut-off indicator.
  • Easy manual reset to operation mode once the cause of the closure is resolved.
  • Acetylene Safety Gaurd ASG with activated shut-off indicator (red)
  • Patented concept to improve safety.
  • Eliminates the need for quick acting shut-off device in the inlet as well as an over-pressure device in the outlet (relief valve).
  • No venting of Acetylene to atmosphere, saving gas and vent pipework
  • Retrofittable to the older pressure control panels BT2000AC and BU13AC

Technical data

Operating pressure P1: 4 - 25 bar

Shut-off pressure P1: 27bar

Control pressure P2: 0.8 / 1.3 / 1.5 / 2.0 bar

Shut-off pressure P2: 1.3 / 1.8 / 2.0 / 2.5 bar


Body: brass

O-rings: EPDM


Inlet / outlet: 1/4”-NPT female

Inlet outlet pressure: 1/8”-NPT female

Temperature range: -30°C to +60°C

Leak rate: <10-3 mbar l/s He

Weight: 2.5 kg


Messer Cutting Systems is a global supplier of cutting edge technology. The company offers products and services for the metalworking industry which set standards world-wide. As market leader in its branch, the machine manufacturer supplies complete solutions and concentrates strategically on advising its customers and customer oriented innovation. Here, the company focusses on the digitalisation of processes and products. Messer Cutting Systems is represented with more than 800 employees in 5 main locations with production facilities and in more than 50 countries.

The product range includes oxyfuel, plasma and laser cutting systems from hand guided machines right up to special machines for shipbuilding as well as machines and equipment for oxyfuel welding, cutting, brazing, soldering and heating. Spare parts, repairs, modernisation, maintenance and service as well as environmental technology round out the product portfolio. In-house software solutions optimise production and business processes. The product range is extended by solutions from technology partners, for example in the field of automation.

An intensive dialogue with our customers has prime position – the modern training centre makes this claim clear. World-wide, Messer Cutting Systems is the partner of choice for cutting systems, oxyfuel technology and customer consultancy.