Manifold

A connecting bar that joins twin scuba tanks into one gas supply, usually with an isolation valve, standard in technical diving.

A manifold joins two back-mounted cylinders into a single gas supply. Each tank keeps its own valve and its own regulator first stage, but the crossbar lets both regulators draw from the combined gas of the twinset. For a technical diver deep inside a wreck or cave, that means a failure of one regulator does not cost half the gas: shut down the affected post and keep breathing everything that remains through the other.

Most manifolds include a central isolation valve. Closing it splits the twinset into two independent tanks, the response to failures that would otherwise drain both, such as a leaking burst disc or a damaged manifold O-ring. Managing these scenarios is drilled relentlessly in technical training as the valve drill or shutdown drill, done by reaching back over the shoulders while holding depth and trim.

Manifolded doubles pair naturally with a backplate and wing and DIN regulators. Divers who prefer fully independent redundancy instead carry sidemount cylinders or independent doubles, trading the shared supply for simpler failure isolation.