Methylacetylene-propadiene (MPS) gas is a type of fuel gas used in oxy-fuel welding and cutting torches, comprising a mixture of several gases.
An MPS gas is a mixture of two or more of propane, butane, butadiene, methylacetylene (propyne, CH<sub>3</sub>Câ¡CH) and propadiene (CH<sub>2</sub>=C=CH<sub>2</sub>). They are marketed under different names including: "MPS", "Chem-O-Lean", "Apachi Gas", "FG-2 Gas", "Flamex" and "natural gas". The most commonly known type of MPS gas is the discontinued MAPP gas.
As a fuel gas, it burns hotter than propylene, propane or natural gas.