A laterally sliding type opening/closing gate of a torsion structure of reasonable cost is implemented. The gate includes: the torsion structure having a closed cross-section consisting of a thin wall installed such that it may cross a sluice and be composed such that its cross-section may make an in-plane rotation around a restriction point on the cross-section and that a torsion moment generated by an applied load and reaction force on the restriction point is transmitted to its terminal due to its torsion rigidity; and a rail that is installed such that it may cross the sluice; and a plurality of axle type supports that has a function of a restriction point and moves along the rail.

A laterally sliding type opening/closing gate of a torsion structure of reasonable cost is implemented. The gate includes: the torsion structure having a closed cross-section consisting of a thin wall installed such that it may cross a sluice and be composed such that its cross-section may make an in-plane rotation around a restriction point on the cross-section and that a torsion moment generated by an applied load and reaction force on the restriction point is transmitted to its terminal due to its torsion rigidity; and a rail that is installed such that it may cross the sluice; and a plurality of axle type supports that has a function of a restriction point and moves along the rail.

A retrofitted flood irrigation valve apparatus includes a housing; a motor coupled to the housing, the motor to generate mechanical energy; a first wheel operatively coupled to the motor, wherein the first wheel is positioned within the housing and wherein the first wheel is to translate the mechanical energy generated by the motor to rotational motion; a second wheel positioned within the housing, wherein the second wheel is to be coupled to a stim of an existing flood irrigation valve; and a coupling between the first wheel and the second wheel, the coupling to transmit the rotational motion from the first wheel to the second wheel, wherein the rotational motion at the second wheel causes actuation of the existing flood irrigation valve.

A retrofitted flood irrigation valve apparatus includes a housing; a motor coupled to the housing, the motor to generate mechanical energy; a first wheel operatively coupled to the motor, wherein the first wheel is positioned within the housing and wherein the first wheel is to translate the mechanical energy generated by the motor to rotational motion; a second wheel positioned within the housing, wherein the second wheel is to be coupled to a stim of an existing flood irrigation valve; and a coupling between the first wheel and the second wheel, the coupling to transmit the rotational motion from the first wheel to the second wheel, wherein the rotational motion at the second wheel causes actuation of the existing flood irrigation valve.

A control gate adapted to be installed across a channel for liquids. The control gate includes a barrier member with a side member that has a circular arcuate section, the barrier member being pivotally mounted at or adjacent to the base of the channel; and a drive for raising and lowering the barrier member. The drive includes a cable, motor and first and second pulleys. The first pulley is coupled to the motor, the cable is secured to opposite first and second ends of the arcuate section, with the second pulley being adjacent to the arcuate section. The cable passes along the arcuate section from the one end to pass under the second pulley in contact therewith, is looped around the first pulley, above the second pulley, then passes under the second pulley and is secured to the second end of the arcuate section.

A control gate adapted to be installed across a channel for liquids. The control gate includes a barrier member with a side member that has a circular arcuate section, the barrier member being pivotally mounted at or adjacent to the base of the channel; and a drive for raising and lowering the barrier member. The drive includes a cable, motor and first and second pulleys. The first pulley is coupled to the motor, the cable is secured to opposite first and second ends of the arcuate section, with the second pulley being adjacent to the arcuate section. The cable passes along the arcuate section from the one end to pass under the second pulley in contact therewith, is looped around the first pulley, above the second pulley, then passes under the second pulley and is secured to the second end of the arcuate section.

An undershot gate system controls flow of liquid through an open channel or pipe. The system includes a gate leaf adapted to be raised and lowered by a control to allow flow of liquid along the open channel or pipe. The gate leaf has a flow diverter at an end of the gate leaf to guide liquid under the gate leaf and through an opening when the gate leaf is in an open position.

An undershot gate system controls flow of liquid through an open channel or pipe. The system includes a gate leaf adapted to be raised and lowered by a control to allow flow of liquid along the open channel or pipe. The gate leaf has a flow diverter at an end of the gate leaf to guide liquid under the gate leaf and through an opening when the gate leaf is in an open position.

An arrangement for controlling and measuring flow. The arrangement includes a fluid control barrier and a flow-measuring apparatus upstream of the fluid control barrier. The fluid control barrier includes a pair of plates for opening and closing a pipe, and the plates are movable towards a center line of the pipe to open the pipe and produce a symmetrical flow profile for the flow-measuring apparatus.

An arrangement for controlling and measuring flow. The arrangement includes a fluid control barrier and a flow-measuring apparatus upstream of the fluid control barrier. The fluid control barrier includes a pair of plates for opening and closing a pipe, and the plates are movable towards a center line of the pipe to open the pipe and produce a symmetrical flow profile for the flow-measuring apparatus.