Product manifolds for use with portable oxygen concentrators and portable oxygen concentrators including such product manifolds

A portable oxygen concentrator, comprising:

• a compressor;
• a feed/waste manifold, comprising:
• an inlet port coupled to the compressor;
• a pair of three-way valves, each three-way valve having a first port, a second port, and a third port, the first port coupled to the compressor;
• and
• an exhaust port, the second port of each of the three-way valves being fluidly coupled to the exhaust port;
• a first sieve bed and a second sieve bed, each of the sieve beds being coupled to the third port of one of the three-way valves;
• a product manifold, comprising:
• a first product port and a second product port, the first product port coupled to the first sieve bed, the second product port coupled to the second sieve bed;
• an accumulator port;
• an output port;
• a flow path, the flow path fluidly coupling the first product port, the second product port, the accumulator port, and the output port to one another;
• a first control port, a second control port, and a third control port fluidly coupling the flow path;
• a first solenoid valve assembly, a second solenoid valve assembly, and a third solenoid valve assembly, each of the first, second, and third solenoid valve assemblies being secured adjacent to a corresponding one of the first, second, or third control ports;
• and
• a first orifice, a second orifice, and a third orifice, the first orifice, the second orifice, and the third orifice being disposed in a corresponding first portion, second portion, or third portion of the flow path, each of the first orifice, the second orifice, and the third orifice being formed by an electrical forming process.

An orifice for use with a product manifold of a portable oxygen concentrator, the orifice comprising:

• a body having a thickness of between about 0.0025 inches and about 0.004 inches and being formed by an electrical forming process, the body comprising:
• a first surface and a second surface opposite the first surface;
• a flow hole extending between the first surface and the second surface;
• a first edge being defined between the flow hole and the first surface;
• and
• a second edge being defined between the flow hole and the second surface, the first edge being substantially the same as the second edge,
• wherein the flow hole is adapted to provide a bidirectional flow tolerance of approximately +/−2.5%.