System for controlling flow through a process region

A device for regulating the flow of fluid, the device comprising:

• a passageway through which the fluid flows from an inlet to an outlet;
• a piston movably mounted so that as the piston moves the piston applies a varying resistance on the flow through the passageway at a constriction point;
• a base;
• a spring attached to the piston and the base, wherein the piston has affixedly mounted thereon a lip such that between the lip and the piston a circular groove is defined, the groove extending more than 180.degree., a portion of one coil of the spring being located in the groove so that the lip restrains the coil from longitudinal movement;
• and
• means for restraining the spring from rotational movement with respect to the piston.

A device for regulating the flow of fluid, the device comprising:

• a passageway through which the fluid flows from an inlet to an outlet;
• a piston movably mounted in the passageway, so that as the piston moves in a direction opposite the flow of fluid, the piston applies an increase resistance on the flow through the passageway at a constriction point;
• a base;
• and
• a spring attached to the piston and the base for supporting the piston such that the spring is not fully compressed when there is no flow through the regulator, the spring having at least one of its ends bent so as to be oriented axially;
• wherein the piston has affixedly mounted thereon a lip such that between the lip and the piston a circular groove is defined, the piston further having defined thereon a hole adjacent one end of the groove, in which the axially oriented end of the spring is inserted.

A device for regulating the flow of fluid, the device comprising:

• a passageway through which the fluid flows from an inlet to an outlet;
• a piston movably mounted in the passageway so that as the piston moves the piston applies a varying resistance on the flow through the passageway at a constriction point, the piston having a distal face exposed to a reference pressure, and a frontal face exposed to fluid in the passageway;
• a base;
• and
• a spring attached to the piston and the base for supporting the piston such that the spring is not fully compressed when there is no flow through the regulator, the spring having at least one of its ends bent so as to be oriented axially;
• wherein the piston has affixedly mounted thereon a lip such that between the lip and the piston a circular groove is defined, the piston further having defined thereon a hole adjacent one end of the groove, in which the axially oriented end of the spring is inserted.

A device for regulating the flow of fluid, the device comprising:

• a passageway through which the fluid flows from an inlet to an outlet;
• a base;
• a piston movably mounted adjacent the base so that as the piston moves away from the base the piston applies an increase resistance on the flow through the passageway at a constriction point;
• and
• a spring attached to the piston and the base for supporting the piston such that the spring is not fully compressed when there is no flow through the regulator, the spring having at least one of its ends bent so as to be oriented axially;
• wherein the piston has affixedly mounted thereon a lip such that between the lip and the piston a circular groove is defined, the piston further having defined thereon a hole adjacent one end of the groove, in which the axially oriented end of the spring is inserted.