The R31 series two-stage regulators available in chrome plated brass or stainless steel are designed for pressure control of high purity and non-corrosive gases in applications where constant delivery pressure is required. The regulators feature metal-to-metal diaphragm seals to prevent gas contamination. The R31B Series Brass Regulator is a Diaphragm-Sensed Dual-Stage High Purity regulator designed for analytical applications where a consistent outlet pressure and flow are desired.