Dam and Powerplant Sump Water Level Indicator
The following describes a simple water level
indicator applied at Glen Canyon Powerplant
which may be useful at other Bureau of
Reclamtion installations:
indicator applied at Glen Canyon Powerplant
which may be useful at other Bureau of
Reclamtion installations:
Closed Line System for Liquid Level Indication
The sump pumps in the bottom of the dam at
Glen Canyon had been controlled by float
switches. The float switches were replaced by
probe operated relays.
Glen Canyon had been controlled by float
switches. The float switches were replaced by
probe operated relays.
Sump water level indication at the pump control
panels was desirable in order to check water
level without going down the 200 steps to the
sump.
panels was desirable in order to check water
level without going down the 200 steps to the
sump.
Since a source of compressed air was not readily
available in the dam, a 'closed line' system
available in the dam, a 'closed line' system
(without air purging the pipe) was installed, and
a 'bell' shaped extension was added to the
bottom of the pipe in the sump. The large
diameter of the 'bell" compared to the rest of the
line confines the change in water level inside the
pipe (due to the increasing pressure of the water)
to the "bell" and error of the system is thus
minimized. The low water level must be below
the bottom of the bell to allow the air charge to
be maintained.
a 'bell' shaped extension was added to the
bottom of the pipe in the sump. The large
diameter of the 'bell" compared to the rest of the
line confines the change in water level inside the
pipe (due to the increasing pressure of the water)
to the "bell" and error of the system is thus
minimized. The low water level must be below
the bottom of the bell to allow the air charge to
be maintained.
Advantages of such a system are that there are
no moving parts involved except the pressure
gage and such a system is easily installed.
no moving parts involved except the pressure
gage and such a system is easily installed.
A sketch of the system is shown on the following
page.
page.
1 (FIST 4- 11)