Atlantic Diving Equipment AZ250 – Emergency Gas Supply Switch Block

Atlantic Diving Equipment Surface Supply Emergency Gas Switch Block AZ250 is a rugged emergency switch block designed for diving with a full-face mask and surface-supplied breathing gas. It allows for a quick switch to an emergency supply of breathing gas from a bailout cylinder in the event of a disruption to the primary supply.

Thanks to its large control knob, the block can be easily operated even while wearing thick gloves, including dry suits used for cold-water diving. The design is intended for attachment to a 2" harness strap and allows for clear and quick control of the emergency gas supply.

Key Features and Benefits

• Emergency gas supply switch: enables breathing gas to be supplied from the emergency bailout cylinder in the event of a failure of the primary source.
• Large control knob: easily accessible and operable even when wearing dry gloves.
• Check valve: prevents gas from flowing back from the emergency cylinder into the inlet line.
• Clearly marked emergency inlet: makes it easy to identify the connection for the bailout cylinder.
• Harness attachment: designed for mounting on a 2" strap.
• Replaceable service kits: the design allows for maintenance and service using readily available service kits.
• Variable inlet connections: three different inlet adapters are included.

How It Works

In the closed position, the two low-pressure outlets are connected to the inlet port. When the emergency switch block is activated, breathing gas is supplied from the emergency bailout cylinder. A one-way valve prevents gas from flowing back from the emergency source into the inlet line.

Technical Specifications

Manufacturer: Atlantic Diving Equipment

Model: AZ250

Device Type: emergency breathing gas supply switch block

Intended Use: diving with a full-face mask and surface gas supply

Mounting: on a 2" (50.8 mm) wide harness strap

Port Connections: 3/8"-24 UNF

Emergency Cylinder Connection: 9/16"-18 UNF for regulator hose

Safety feature: one-way valve to prevent backflow

Inlet adapters: 3 different adapters included in the package

Service: service kits available

Package contents

• Atlantic Diving Equipment AZ250 Emergency Switching Block
• Three different inlet adapters

The Atlantic Diving Equipment AZ250 is an essential piece of equipment for professional divers using a surface-supplied breathing gas system. It provides access to an emergency gas source and, thanks to its intuitive operation, enables a quick response in the event of a failure of the primary gas supply.