Glossary of Gate Terms
#
125# Drilling
ANSI standard drilling pattern for cast iron flanges
25# Drilling
ANSI standard drilling pattern for cast iron flanges
A
Automatic Level Control Gate
A gate that is used in an open channel and will regulate the level on one side of the gate with no need for an operator or external power
C
Cover
The part of the gate that moves to regulate water flow through the gate
Crest Gate
See: Radial Gate
D
Decanting Valve
See: Telescoping Valve
Design Head
Head measured from surface of water to centerline of gate, in ft (m), for the design of the gate
Downward Opening
See: Weir Gate
Drain Valve
See: Mud Valve
E
Electric Motor Operator
An electric motor used for operating the gate; often abbreviated as EMO
F
Floorbox
An embedded box that houses an operating nut
Flushbottom
A frame that is designed for embedding into the floor of a structure; uses a resilient seal
Frame
The stationary part of the gate that mounts to a structure or pipe
Flap Gate
A gate where the cover is hinged to the frame and flaps open to allow water to flow through gate; designed for seating heads and swings open under unseating heads
G
Gate Valve
A bonneted gate for in-line use; not a product manufactured by Waterman
Guide
A component of the frame in which the cover travels
K
Knife Gate
A specialty gate used to cut through extremely thick fluids
L
L/r Ratio
Formula used to assist in placing stem guides; length divided by radius of gyration
Lift
A manual, electric, or cylinder-type device used to operate or move the gate cover
Limit Nut
A nut that is attached to the stem to limit the travel of the gate and prevent it from over-travelling
Limit Switch
The part of an Electric Motor Operator that is set to limit the travel of the gate
Lock Nut
See: Limit Nut
M
Mud Valve
A valve designed for settling basins and treatment plants where sedimentary material must be flushed
N
Non-Rising Stem
A stem that rotates to raise and lower the gate cover but does not raise and lower along with the gate cover
O
Operating Head
Head measured from surface of water to centerline of gate, in ft (m), used for the normal conditions the gate will see
Operating Nut
A nut used to operate the gate
Overshot Gate
See: Tilting Weir
P
Penstock
See: Slide Gate
Plug Valve
Valves with cylindrical or conically tapered “plugs” which can be rotated inside the valve body to control flow through the valve; not a product manufactured by Waterman
Position Indicator
Shows the position of the cover; typically mylar strip or dial-type
R
Rising Stem
A stem that rises up and down with the gate cover
Radial Gate
A type of radial arm gate used in dams and canal locks to control water flow; side view of a radial gate resembles a slice of pie with the curved part of the piece facing the source or upper pool of water and the tip pointing toward the destination or lower pool
S
Screw Gate
See: Slide Gate
Seals
The part of the gate that seals the cover against the frame
Seating Head
Head measured from surface of water to centerline of gate, in ft (m), that exerts force against the cover as to push the seats together
Seats
The part of the gate were the cover slides against or contacts the frame
Self-Regulating Tide Gate
A specialized type of flap gate that will allow water to flow back and forth through wetlands but closes as tides get high to protect against flooding
Slide Gate
A vertically sliding gate with seats consisting of a self-contained frame or non-self-contained frame and a slide; slide gates are raised and lowered by means of a stem using a manually operated lift, electrical motor operator, or by a cylinder
Sluice Gate
See: Slide Gate
Spindle
See: Stem
Stem
A rod that connects the gate cover to the lifting device
Stem Cover
A cover attached to the top of the lifting device to protect the stem threads
Stem Guide
A device used to protect the stem from buckling under a compressive load
T
Tainter Gate
See: Radial Gate
Telescoping Valve
A valve with sliding, telescoping members to regulate water flow in a pipeline with minimum disturbance to pond
Thimble
An anchoring fixture embedded to the wall to which the gate is bolted
Thrust Nut
A nut that provides stem attachment to the gate cover
Tide Gate
See: Flap Gate
Tilting Weir Gate
Consists of a gate leaf, hinge, and hoist mechanism; the gate lowers to allow water to flow over the top of the cover
U
Undershot Gate
See: Radial Gate
Unseating Head
Head measured from surface of water to centerline of gate, in ft (m), that exerts force against the cover as to push the seats apart
W
Wedges
A device on the cover and frame that forces or wedges the cover against the frame
Weir Gate
A downward-opening slide gate where water or wastewater flows over the top of the slide
