47
Bulkhead gates
. Bulkhead gates are usually installed at the entrance and used to unwater fluidways for
inspection or maintenance and are nearly always opened or closed under balanced pressures.
Stop logs
. Stop logs are installed in the same manner and
perform the same function as bulkhead gates.
A stop log may be considered as a
section of a bulkhead gate which has been made of several units to
permit easier handling.
permit easier handling.
Gates.
Closure or regulating devices meeting the above definition of "gates" appear in a variety of forms.
The more common types are discussed in the following sections.
1.
Radial or Tainter Gates. Radial gates
primarily as spillway crest gates but are also used in canals or other open channel applications. A radial
gate basically consists of a skinplate, shaped like a cylindrical section, connected to radial arms which
converge to a horizontal pivot pin. The gate is raised or lowered usually by a wire rope or chain and
sprocket hoist.
gate basically consists of a skinplate, shaped like a cylindrical section, connected to radial arms which
converge to a horizontal pivot pin. The gate is raised or lowered usually by a wire rope or chain and
sprocket hoist.
2. Drum Gates.
buoyant vessel or "drum" hinged to the spillway crest. A water chamber below the drum is filled or drained
to raise or lower the gate.
to raise or lower the gate.
3. Slide Gates.
Slide gates, in their various configurations, may be used as guard or regulating
gates for closed, high pressure conduits, such as penstocks and outlet works, or for open channel
flow such as canals. The construction of a slide gate can vary a great deal. The cast iron slide
gate consists of a flat or rectangular leaf that is moved within a frame over a circular or
rectangular opening. The leaf is connected to a hoist by a stem which is supported by guides
attached to the concrete above the opening. High pressure gates and outlet gates are also slide
gates. They consist of a leaf, a body, and bonnet embedded in concrete, and some type of hoist
for raising and lowering the leaf. Since slide gates usually seal downstream, the downstream
mating surfaces between the leaf and the body act as bearing and sealing surfaces.
flow such as canals. The construction of a slide gate can vary a great deal. The cast iron slide
gate consists of a flat or rectangular leaf that is moved within a frame over a circular or
rectangular opening. The leaf is connected to a hoist by a stem which is supported by guides
attached to the concrete above the opening. High pressure gates and outlet gates are also slide
gates. They consist of a leaf, a body, and bonnet embedded in concrete, and some type of hoist
for raising and lowering the leaf. Since slide gates usually seal downstream, the downstream
mating surfaces between the leaf and the body act as bearing and sealing surfaces.
shows an outlet works slide gate.
4. Wheel- and Roller-Mounted Gates.
Wheel-mounted (fixed wheel gates) and roller-mounted (coaster
gates) gates consist of a flat structural steel gate leaf with a roller system or a series of wheels fixed to the
leaf to transfer the hydraulic load from the gate to tracks imbedded in concrete. These gates are used as
spillway gates or as the primary guard gate for a penstock or outlet conduit. Depending on the application,
the hoist for the gate may be a hydraulic cylinder or some type of a mechanical hoist.
leaf to transfer the hydraulic load from the gate to tracks imbedded in concrete. These gates are used as
spillway gates or as the primary guard gate for a penstock or outlet conduit. Depending on the application,
the hoist for the gate may be a hydraulic cylinder or some type of a mechanical hoist.
show typical installations.
5. Jet Flow Gates. Jet flow gates are used strictly for water regulation through outlet conduits. A jet flow
gate is similar to a slide gate consisting of a leaf, a body, a bonnet, and a hoist to position the leaf. The
outlet of the gate is circular in cross section, rather than square or rectangular as a slide gate, with a conical
nozzle upstream of the gate. This nozzle produces a contracted, jet type discharge that jumps over the gate
leaf slot.
gate is similar to a slide gate consisting of a leaf, a body, a bonnet, and a hoist to position the leaf. The
outlet of the gate is circular in cross section, rather than square or rectangular as a slide gate, with a conical
nozzle upstream of the gate. This nozzle produces a contracted, jet type discharge that jumps over the gate
leaf slot.
6. Cylinder Gates.
Cylinder gates are used on circular, vertical intake structures and can be used as a
guard gate for penstocks or outlet conduits or to regulate flow. A cylinder gate consists of a cylindrical