TUSA s RS 790 Regulator The all chrome plated marine brass first stage regulator is a balanced diaphragm design which is environmentally sealed The diaphragm membrane transmits the pressure changes to the internal mechanism eliminating the need for the surrounding water to enter the intricate mechanism The benefit of this type of first stage design is that none of the internal parts are exposed to contaminants such as salt sand chlorine or pool acids These environmental contaminants cause corrosion and mineral deposits to form on the internal mechanism deteriorating regulator performance TUSA has taken this concept one step further with the addition of a Dry Ambient Pressure Chamber A standard diaphragm first stage regulator allows some water to enter the main spring cavity Although the cavity is not associated with the intricate internal components it does allow the cold water to rest against the primary diaphragm cooling the air that passes through the first stage