Constant mass flow valves

The Hydrogom CMF valve

Hydrogom is a Dutch based company specialised in the production and sale of the hydrogom CMF valve. Therebreathersite is a dealer for selling these valves to interested rebreather diver. So if you are interested, please send me an email and i will bring you in contact with Hydrogom.

CMF valves are designed to convert an existing rebreather to a CMF system. The principle behind this is that a diver receives a fixed dose of oxygen injected into the system through this valve that is as close as possible to his metabolic consumption. By setting this dose, long-term diving with such a system is possible. Once the setpoint drops because there is too little oxygen in the loop, a button can be pressed on the valve that operates a bypass function and oxygen is re-injected into the loop. The dose is very precise and shortage of oxygen can occur as the diver performs heavier work. The valves are made of very high-quality materials. This page shows you the details of the system.

Note that feeding these valves requires a special modified first stage with a fixed intermediate pressure. Normal depth compensated first stages will not give the right result.

Also, for homemade rebreathers there is no CE mark and diving is at your own risk. Before delivery of this valve, a warranty has to be signed. The diver declares to understand what he is doing with this valve and that the manufacturer cannot accept any liability for accidents.

The valve is made of stainless steel and can be connected to the supply gas in two ways. The valve has a build in filter system.
The orifice is a Rubin or steel punched by micro laser, or a Lohm precision orifice in hard metal. The middle picture shows the valve in normal CMF action. The right picture shows the manual bypass activated.