A first reducing stage for two-stage regulator assemblies includes a first chamber for a high-pressure breathable gas; a second chamber for the breathable gas at an intermediate pressure; a pressure reducing valve connecting the two chambers and having a valve seat with an opening for communication between the two chambers; and a plug cooperating with the valve seat and dynamically connected to a sensor exposed to water to the outer water pressure. The sensor is at least partly accommodated in a housing chamber defined by one or more elements cooperating to provide support and partial movement constraint to the sensor, and forming the housing chamber and/or at least part of the sensor. The one or more elements are made of a material or a combination of materials having thermal conductivity lower than a metal material, and mechanical properties that do not affect correct operation compared to metal materials.

A method and system to deliver to a submerged diver only that amount of breathing gas volume and pressure required at the diver's depth by controlling the actions of a valve in response to inhalation demand. A sensing unit detects diver respiration, and a logic unit controls a valve to deliver breathing gas to the diver from a breathing gas source via a tube.

A semi-closed circuit gas recycling scuba diving breathing apparatus having a breathing loop. The breathing loop has a breathing bag to be supplied by at least one gas tank and a recycling chamber. The gas tank is connected to an inlet of the breathing bag by a first duct and a second duct having respectively a demand regulator and a fixed nozzle configured to deliver respectively a first gas input and a second gas input to the breathing bag. Advantageously, the apparatus has a third duct having a gas flow regulator configured to deliver at a variable mass flow, a third gas input to the breathing bag, and a diving condition sensor, configured to measure a physiological parameter of the diver or the depth. The apparatus is advantageously configured to make the variable mass flow vary according to data of the sensor to optimise the consumption of gas.

A device for heat exchange for use with underwater diving equipment including a pressurized gas source is disclosed. The heat exchange device includes a manifold and a heat sink. The manifold distributes gas supplied from the pressurized gas source to breathing equipment. The heat sink is for warming up the gas before the gas is distributed to the breathing equipment using heat exchange with ambient water surrounding the heat sink. The manifold and the heat sink are connected such that the gas warmed up by the heat sink returns to the manifold before being distributed to the breathing equipment. The returning warm gas may warm up the manifold and the cold gas entering the manifold.

A regulator first stage for two-stage underwater breathing apparatuses includes a reduction chamber communicating with a high-pressure gas supply through a balance valve, which is influenced by the pressure of the external environment by a balance diaphragm that, by way of a suitable actuator, acts on the valve. The reduction chamber includes one or more medium pressure outlets, having axes parallel to the operating axis of the balance valve. In one configuration, one or more medium pressure outlets are also provided having axes orthogonal to the operating axis of the valve.

A first-stage diving regulator comprising the profiled body, swivel turret and the cylinder connector, whereas the axis of rotation of the swivel turret is perpendicular to the body axis, thus enabling by preferable arrangement of medium pressure LP ports and high pressure HP ports of the body, and preferable arrangement of medium pressure LP ports in the swivel turret and proper hose configuration at any possible equipment configuration by using the same first-stage regulator.

An integrated manifold system is disclosed that combines in a single, compact, unitary assembly a one-piece, machined manifold for connecting air supply cylinders with a first stage regulator and recharge port. The manifold body has at least one bottle port configured to removably receive a bottle of pressurized air, a first stage regulator chamber, a quick disconnect fitting port, an air channel in fluid communication with the at least one bottle port and the first stage regulator chamber, and an outlet channel in fluid communication with the first stage regulator chamber.

A semi-closed circuit gas recycling scuba diving breathing apparatus having a breathing loop. The breathing loop has a breathing bag to be supplied by at least one gas tank and a recycling chamber. The gas tank is connected to an inlet of the breathing bag by a first duct and a second duct having respectively a demand regulator and a fixed nozzle configured to deliver respectively a first gas input and a second gas input to the breathing bag. Advantageously, the apparatus has a third duct having a gas flow regulator configured to deliver at a variable mass flow, a third gas input to the breathing bag, and a diving condition sensor, configured to measure a physiological parameter of the diver or the depth. The apparatus is advantageously configured to make the variable mass flow vary according to data of the sensor to optimise the consumption of gas.

An apparatus for adjusting the partial pressure of gaseous mixtures comprises a housing and piston. The housing defines a chamber coupled to an oxygen metering orifice, diluent metering orifice, vent port and gas outlet. The oxygen metering orifice provides oxygen to the chamber and the diluent metering orifice provides diluent gas to the chamber. The piston is movably positioned in the chamber and includes first and second sealing devices. The chamber is sectioned into a mixing chamber, a diluent chamber and a reference chamber located between the mixing chamber and diluent chamber. The diluent chamber receives a diluent gas referenced at ambient pressure and the reference chamber is charged with a gas having a reference pressure. The piston changes positions within the chamber depending on a force balance created by a pressure differential between the reference pressure and ambient pressure.

An integrated manifold system is disclosed that combines in a single, compact, unitary assembly a one-piece, machined manifold for connecting air supply cylinders with a first stage regulator and recharge port. The manifold body has at least one bottle port configured to removably receive a bottle of pressurized air, a first stage regulator chamber, a quick disconnect fitting port, an air channel in fluid communication with the at least one bottle port and the first stage regulator chamber, and an outlet channel in fluid communication with the first stage regulator chamber.