Nitrox Ready and suitable for use with air or argon, the DGX Gears FIRST Regulator has a classic balanced downstream (aka "flow-by") piston first stage and includes an over pressurization relief valve (OPV). The value priced FIRST is perfect for inflation, pony bottle and oxygen accelerated decompression applications. This inexpensive first stage provides good performance for its design class and we have no concerns using the FIRST regulator for recreational sport SCUBA diving depth applications. The FIRST is popular for reliability and minimal maintenance in dive shop rental fleets. However, we do not recommend the FIRST for breathing use in extended range depths or in very cold waters.

The FIRST is proven exceptionally reliable and does not have a recommended periodic maintenance interval but we suggest checking for signs of wear after each cycle of 50 to 100 dives by measuring and evaluating intermediate pressure (IP). We believe our customers have the right-to-repair, so we publish a detailed service manual and we sell without restriction all service parts. See the Product Attachments tab for the service manual including IPB and torque values.

On dedicated inflation systems or on breathing systems where the second stage has a flow stop cut-off installed, there is no regulator second stage to provide relief should the high pressure seat begin to fail and the intermediate output pressure rise. Without a way to relieve the pressure, the device could begin inflating rapidly or the low pressure hose could rupture. Best practice in such configurations is to include the over-pressure relief valve to provide the same relief function as a regulator second stage. If you configure the FIRST with a downstream second stage, then the OPV is unnecessary and may be removed if you wish.