Self-regulating storm water control valve
View Patent ↗A mechanical flow control valve for use in low pressure hydraulic systems, the valve includes a flow tube having an inlet and an outlet, a flow restrictor within a flow path, a fixed piston within the flow tube, a movable plunger assembly slidably attached to the fixed piston, the plunger assembly including a plunger head having a profile shape at least a portion of which increases toward the inlet. The movable plunger assembly is biased toward the inlet of the flow tube and is configured to move within the flow restrictor in response to one or more flow induced forces on the moveable plunger assembly thereby maintaining a target designed flow rate through the flow restrictor.
1 . A mechanical flow control valve for use in low pressure hydraulic systems, the valve comprising:
a flow tube having an inlet and an outlet;
a flow restrictor within a flow path;
a fixed piston within the flow tube;
a movable plunger assembly slidably attached to the fixed piston, the moveable plunger assembly including a plunger head having a profile shape at least a portion of which increases toward the inlet, wherein the moveable plunger assembly and the fixed piston create a compressible air volume used to bias the moveable plunger assembly; and
a low friction sleeve liner between the moveable plunger assembly and the fixed piston;
wherein the movable plunger assembly is biased toward the inlet of the flow tube; and
wherein the movable plunger assembly is configured to move within the flow restrictor in response to one or more flow induced forces on the moveable plunger assembly, thereby reducing flow through the flow restrictor.
2 . The mechanical flow control valve according to claim 1 , wherein the low friction sleeve liner and the fixed piston are the same material.
3 . The mechanical flow control valve according to claim 2 , wherein the low friction sleeve liner and the fixed piston are made of Ultra High Molecular Weight Polyethylene (UHMWPE), Polytetrafluoroethylene (PTFE), Acetal, or graphite.
4 . The mechanical flow control valve according to claim 1 , wherein the fixed piston has a piston length; and the movable plunger assembly further comprises a piston sleeve having a piston sleeve length that is approximately twice that of the piston length.
5 . The mechanical flow control valve according to claim 4 , wherein the movable plunger assembly has a total length to mass ratio small enough to be supported by the fixed piston as to prevent excessive bending forces, racking, or binding for an entire stroke of the movable plunger assembly.
6 . The mechanical flow control valve according to claim 5 , wherein the maximum cross-sectional area of the plunger head is smaller than the cross-sectional area of the flow restrictor.
7 . The mechanical flow control valve according to claim 6 , wherein the flow tube has a cross-sectional area and wherein the maximum cross-sectional area of the plunger head is less than or equal to 75% of the flow tube cross-sectional area.
8 . The mechanical flow control valve according to claim 7 , wherein the fixed piston has a cross-sectional area that is 75-90% the maximum cross-sectional area of the plunger head.
9 . The mechanical flow control valve according to claim 8 , wherein the flow tube has an inside diameter less than or equal to 18 inches.