Floval SE Flowmeter from Air Liquide

FLOVAL SE is a rotameter for the delivery of a gas from a low-pressure medical outlet (wall outlet or reducer connector). The single-scale flow measurement system is completely independent of the counter-pressure generated downstream by connection accessories.

The flow adjustment needle knob provides high precision. FLOVAL SE offers a wide selection of flow scales (from 0 to 30 l/min) and available gases (O2, Air, Nitrogen, CO2, N2O). Supply pressures vary depending on model (from 3.5 to 5 bar). The flowmeter body is made of chrome-plated brass.

For more detail: http://www.airliquidemedicalsystems.com/en/gas-equipment/detente-debitmetrie-hopital/floval-se.html