The 322 Series single stage regulator is for primary pressure control of high purity gases (up to grade 5.5) and mildly reactive gases. However, it is not suitable for toxic or highly corrosive gases. Due to the pressure rise associated with high-pressure cylinder depletion, CONCOA recommends single-stage regulators for primary pressure control in applications that can tolerate minor fluctuations in outlet pressure due to diminishing inlet supply or where inlet pressure is constant or under 500 PSIG (34 BAR).