Transcript Valves and Appurtenances

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Valves and Appurtenances
Types of Valves
Air Valves
 Control Valves
 Pressure Relief Valves
 Pressure Reducing Valves

Air Valves

Air valves are needed to control air in
and out of pipe lines.
Types of Air Valves
Air release valve
 Vacuum relief valve
 Air and vacuum valve
 Combination air and vacuum relief
valve

Air Release Valve
A small orifice,
continuous acting
valve for air release
only.
 Used at closed
summits to prevent
formation of air
pockets.

Vacuum Relief Valve

A large orifice valve for vacuum relief
only.
Air and Vacuum Valves


Valves with large orifices
which allow air to exhaust
from the pipeline during filling
(not during operation) and
allow air to enter the pipeline
during emptying.
Generally used at either upper
or lower ends of pipeline.
Slide Gate
Used to let water into
gravity pipeline,
usually from irrigation
canal.
 Control mechanism is
disk or plate sliding
over pipe opening.

Check Valves
In-line back flow
prevention valve.
 Generally used to
prevent surge at
pumps and to
maintain water column
in pipelines.
Swing
check

Double
swing
check
Rubber
flapper
check
Check Valves (cont.)
Slanting
disk
check
Automatic
control
check
Silent check
(center guided)
Butterfly Valve
In-line distribution
valve
 Control mechanism is
a rotating disk inside
of valve housing.

Ball Valve
In-line distribution
valve
 Control mechanism is
a rotating hollow ball
inside of valve
housing.

Gate Valve
In-line distribution
valve
 Control mechanism is
a sliding plate inside
of valve housing.

Globe Valve
In-line distribution
valve
 Control mechanism is
plunger inside of valve
housing.

Alfalfa Valve
Outlet distribution
valve
 Control mechanism is a
threaded plate or cap
on outside of valve
body.
 Requires hydrant to
open and close.

Alfalfa Valve (cont.)
Pressure Relief Valves

A valve used to
relieve excess
pressure that
develops in the
pipeline.
Flow Meter
In-line device used to
measure flow.
 In NRCS we generally
require meters that
give both
instantaneous flow
rates and cumulative
volumes.

Air Vent Assembly
Used at at high points to provide
combination air and vacuum relief
 Outlet of vent must be located above
the hydraulic grade line for all flows.

Air Vent Assembly (cont.)
Riser Assembly
Pipe attached to underground pipeline to
deliver water to surface outlets or
system valves.
 A chamber may be required at base for
certain installations.

Riser Assembly (cont.)
Drain Assembly
Valve and pipe assembly used to empty
a pipeline.
 Generally either gravity or pump out
configurations are used.

Drain Assembly (cont.)
Thrust Control

Anchors or thrust blocks used to resist
axial thrust in the pipeline at abrupt
changes in pipe grade, at changes in
pipe alignment, at reductions in pipe
diameter, at points of divergence, and
at ends of line.
Thrust Control (cont.)
NPRC Project
NPRC Project (cont.)
NPRC Project (cont.)
NPRC Project (cont.)
NPRC Project (cont.)
NPRC Project (cont.)
10” Pressure Reducing Valve
NPRC Project (cont.)
NPRC Project (cont.)
NPRC Project (cont.)
Final Installation