Manifold Valves for twins

Complete Isolation Manifolds for Backmount Doubles

A manifold for twin cylinders serves two functions: it connects both cylinders so either regulator can access gas from both tanks simultaneously, and (in ISOL format) it provides an isolation valve in the centre bridge that allows one side to be shut off independently from the other. The isolation function is non-negotiable for technical diving — it is the redundancy mechanism that preserves gas from one cylinder when the other side fails.

Manifold Formats in This Range

ISOL manifolds (740232/741232, 741235/6, 742300/743300) include the isolation valve as part of the bridge. These are the standard technical diving configuration. The centre knob operates the isolation valve — turning it clockwise closes off gas flow between the left and right cylinders.

Screw SA manifolds (742232, 744300/745300/746300) use a screw-type bridge connection without an integrated isolation valve. They allow both cylinders to be accessed simultaneously but do not provide the ability to isolate one side. These are typically used in training, recreational, or specific configurations where independent isolation is provided at the valve level rather than the manifold level.

Screw LI (742230/1) is a screw-type bridge with a left-integrated design — the left valve and bridge connection share an integrated format. The 225 € price point reflects the more complex machining of this configuration.

Pressure Rating Selection

The 232 bar manifolds are appropriate for cylinders filled to a maximum of 230–232 bar. The 300 bar manifolds are required for cylinders filled to 300 bar and are also compatible with 232 bar fills — making them the higher-flexibility choice if you may use both fill pressures. Do not use a 232 bar manifold on 300 bar cylinders.

Cylinder Spacing: 171 mm vs. 140–203 mm

The manifold length spans the gap between the two valve connections. The 171–203 mm designation covers a range — the manifold bridge length accommodates cylinders with neck spacing from 171 mm to 203 mm. The 140–203 mm range on the screw SA models covers slightly narrower spacing for smaller-diameter cylinders. Measure the centre-to-centre neck spacing of your assembled cylinder pair with bands in place before selecting the manifold length.

What to Look For

• ISOL is the technical diving standard: For any dive profile involving decompression obligations or overhead environments, an ISOL manifold is required. Screw SA manifolds without isolation are used in specific training or recreational configurations.
• Matching pressure rating to your fill pressure: If you fill to 300 bar, you need a 300 bar manifold. If you fill to 232 bar, either a 232 bar or 300 bar manifold will work — the 300 bar version provides future-proofing if you later switch cylinders or fill pressures.
• O-ring maintenance: The manifold-to-valve interface seals via o-rings at each connection point. Inspect before every dive trip and replace if nicked or extruded. Carry spare manifold o-rings on multi-day expeditions.

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