HYDROGEN SUPPLY PRESSURE REGULATOR
Hydrogen gas flow from high pressure storage to a lower pressure hydrogen-using device is managed using one or more axial flow pressure regulators comprising a cup-shaped housing with an inlet for high pressure hydrogen gas at one end of the flow axis and a closure with a low pressure hydrogen outlet at the other end of the flow axis. A piston head with a piston stem are aligned on the flow axis and a hydrogen flow passage is formed up the stem and through the piston head to the hydrogen flow outlet. One or more combinations of a corrugated tubular bellows (or like expansive sealing vessel) with static seals attaching one bellows end to the piston stem or head and the other bellows end to the housing or closure are used to accommodate axial movement of the piston while isolating and containing hydrogen gas flow from a high pressure chamber at a flow entrance to the piston stem to a low hydrogen pressure chamber at the piston head and closure outlet.
1 . A pressure regulator for controlling a flow of hydrogen gas from a source of hydrogen at a first hydrogen gas pressure to a hydrogen-using device at a lower hydrogen gas pressure, the pressure regulator comprising:
a piston comprising a piston head and a piston stem, the piston head and stem having a longitudinal axis, the piston stein having a distal end opposite the piston head and defining a flow passage for hydrogen that extends from a flow passage inlet at the distal end and along the longitudinal axis and through the piston head at a flow passage outlet;
a regulator body with a central longitudinal axis, the body having an inlet for hydrogen gas at the first pressure at one end of the central axis and an opening at the other end of the central axis, the inlet terminating in a sealing seat, the body being further shaped to accommodate the piston head and piston stein with the distal end of the stem being movable along the central axis into engagement with the sealing seat of the inlet and the piston head and its flow passage outlet being aligned within the opening of the regulator body at the central longitudinal axis;
a closure member attached to the end the regulator body having the opening, the closure member having an outlet for hydrogen gas at the lower hydrogen pressure, the outlet being centered on the central longitudinal axis of the regulator body and on the flow passage outlet in the piston head; and
an expansible vessel with one end attached with a first static seal to the regulator body and a second end attached with a second static seal to the piston stem so that inside of the vessel defines a first hydrogen gas flow chamber between the regulator body and the piston stem thereby directing hydrogen gas flow from the hydrogen gas inlet into the flow passage in the piston stem, the vessel accommodating axial movement of the piston along the central longitudinal axis.
2 . A pressure regulator as recited in claim 1 in which the expansible vessel has a cylindrical tubular shape.
3 . A pressure regulator as recited in claim 1 in which the expansible vessel is a tubular conjugated bellows.
4 . A pressure regulator as recited in claim 1 in which the outside of the expansible vessel accommodates an atmospheric pressure chamber in the regulator.
5 . A pressure regulator as recited in claim 1 in which the expansible vessel is formed of stainless steel sheet material or polyethylene sheet material.
6 . A pressure regulator as recited in claim 1 in which at least one of the first and second static seals comprise a spring-biased ring.
7 . A pressure regulator as recited in clam 1 in which a spring force is applied to the piston head to urge the piston stem away from the hydrogen inlet sealing seat.
8 . A pressure regulator as recited in claim 1 , the regulator further comprising:
a second hydrogen gas flow chamber between the piston head and the closure member, hydrogen gas flowing from the piston head into the second chamber to exert a gas pressure on the piston head and to flow from the second chamber through the outlet in the closure member.
9 . A pressure regulator as recited in claim 8 in which a second expansible vessel with one end attached with a third static seal to the piston head and another end attached with a fourth static seal to the regulator body or closure member to define the second hydrogen gas flow chamber and to prevent leakage of hydrogen from the regulator apart from intended flow of hydrogen gas through the outlet in the closure member, the vessel accommodating axial movement of the piston along the longitudinal axis.
10 . A pressure regulator as recited in claim 9 in which the second expansible vessel is a tubular corrugated bellows.
11 . A pressure regulator as recited in claim 9 in which the expansible vessel is formed of stainless steel sheet material or polyethylene sheet material.
12 . A pressure regulator as recited in claim 9 in which at least one of the first and second static seals comprise a spring-biased ring.
13 . A pressure regulator for controlling the flow of hydrogen gas from a source of hydrogen at a first hydrogen gas pressure to a hydrogen-using device at a lower hydrogen gas pressure, the pressure regulator comprising:
a piston comprising a piston head and a piston stem, the piston stem having a distal end opposite the piston head and defining a flow passage for hydrogen that extends from a flow passage inlet at the distal end to a flow passage outlet at the piston head;
a regulator body having at one end an inlet for hydrogen gas at the first pressure and at the other end an opening, the inlet terminating in a sealing seat, the regulator body being further shaped to accommodate the piston with the distal end of the stem being movable into engagement with the sealing seat of the inlet;
a closure member attached to the end of regulator body having the opening, the closure member having an outlet for hydrogen gas at the lower hydrogen pressure, the outlet being aligned with the flow passage outlet in the piston stem;
a first tubular corrugated bellows with one end attached with a first static seal to the regulator body and a second end attached with a second static seal to the piston stem, the inside of the bellows sealing a first hydrogen gas flow chamber between the regulator body and the piston stem thereby directing hydrogen gas flow from the hydrogen gas inlet into the flow passage in the piston stem, the outside of the tubular bellows accommodating an atmospheric pressure chamber that is vented to the atmosphere, the first tubular bellows further accommodating axial movement of the piston;
a second tubular corrugated bellows with one end attached with a third static seal to the piston head and another end attached with a fourth static seal to the regulator body or the closure member to contain a second hydrogen gas flow chamber between the piston head and the closure member that receives hydrogen flow from the flow passage outlet at the piston stem, the hydrogen flow flowing from the second hydrogen gas chamber through the outlet in the closure member and exerting a gas pressure on the piston head, the second tubular bellows further accommodating axial movement of the piston head; and
a spring located within the atmospheric pressure chamber of the regulator body and applying a spring force to the piston head to urge the piston stem away from the hydrogen inlet sealing seat.
14 . A pressure regulator as recited in claim 13 in which at least one of the first and second tubular corrugated bellows is formed of a material comprising at least one of stainless steel sheet material and polyethylene sheet material
15 . A pressure regulator as recited in any of claim 13 in which at least one of the first, second, third, and fourth static seals comprise a spring-biased ring seal.