First Stage Regulator
Definition
The first stage regulator attaches to the scuba tank and reduces high-pressure air to an intermediate pressure for delivery to the second stage.
More on First Stage Regulator
The first stage is the heart of the regulator system. It mounts to the tank valve (DIN or yoke) and reduces the 200–300 bar tank pressure to about 8–10 bar above ambient. This intermediate pressure feeds the second stage, inflator hoses, and other accessories. First stages can be piston or diaphragm types, and balanced or unbalanced in performance. Environmentally sealed options are ideal for cold or contaminated water diving. Regular servicing ensures safe and efficient operation.
Frequently Asked Questions
Piston first stages are simpler and perform well at depth, while diaphragm models are more environmentally sealed and suitable for cold or dirty water.
Typically 1–2 high-pressure ports (for SPG) and 4–5 low-pressure ports for second stage, inflator, and accessories.
Yes, especially piston models. Sealed diaphragm designs reduce this risk and are preferred for temperatures below 10°C (50°F).
Balanced regulators deliver consistent airflow regardless of tank pressure, offering smoother breathing throughout the dive.
Annually or after 100 dives, whichever comes first, as per manufacturer recommendations.