Acetylene Regulator & Oxygen Regulator HEAVY DUTY DOUBLE STAGE REGULATORS WITH PRESSURE-GAUGE. Double stage regulator,first stage piston-loaded and secon stage spring-loaded, with pressure gauge is a time and industry proven design that has evolved from engineering experience and technology to ensure the accurate control of industrial gases with minimum outlet pressure fluctuations and stable outlets pressures. BD and BSD are visibly strong, no nonsense, durable construction that sets the standard for pressure regulators used throughout heavy welding, brazing,soldering, and gas shielding applications. Regulator uses the most up-to-date production and testing facilities to ensure a reliable, versatile, affordable, high performance regulator.