Installation - Seametrics AG3000p Instructions Manual

INSTALLATION

Straight Pipe Recommendations (X = diameter)
NOTE: These configurations are to be used as general guidelines and do not cover every possible installation. A
combination of two or more obstructions will require additional straight pipe. If there is any concern about the
length of pipe required for a specific application, please contact your local dealer.
Two Elbows In Plane
2X
Reduced Pipe
2X 1X
Installing a meter after a pump. Most meters will be installed
in systems with some sort of pump, and while the pump is
unlikely to have a negative effect on meter performance, there
are some situations where understanding the effect the pump
has on the flow profile, and by extension on the meter will be
of utmost importance.
Air vents should be installed in the same unobstructed pipe run
as the meter and should be located relatively close to the me-
ter. Constant bleed air vents are recommended because simple
check type air vents will not open once the system is under
pressure and an accumulation of air can build up behind them.
Significant amounts of air entrained in the flow of water, wildly
erratic flow profiles and water that travels through the pipe with
significant swirl will cause the meter to read erratically, some-
times very erratically, or not read at all. Therefore, the designer
or installer must reduce or eliminate these issues when they are
likely to occur.
Every installation is different, but we can offer some general
guidelines when it comes to the placement of your pump and
meter. And again, in most cases, the pump will have no, or very
little effect on the meter's performance, but some care should
be taken to assure your installation has the best chance for
success.
Confirm there is adequate head to insure a full pipe of water
through the meter (a valve downstream of the meter may be
required).
Vertical Turbine Pumps drawing from deep wells, or from
well under the surface of the water will generally have very little
effect on the flow profile of the water by the time the water
reaches the meter.
Short Coupled Lift Pumps can, but will not necessarily, cause
an erratic or swirling flow profile. Care must be taken during
system layout to avoid these issues. The inlet of these pumps
will be located near the surface of the water supply and can
both suck air from the surface and swirl the water around the
pump. This swirling water itself may be a contributing factor of
poor flow profile and also lower the surface of the water over
the pump inlet.
Vertical Turbine Pump Before Meter
2X
Seametrics • 253.872.0284
1X
Short Coupled Lift Pump Before Meter
Two Elbows, Out Of Plane
2X 1X
Expanded Pipe
5X 2X
Propeller Meter After Meter
3X
The absolute minimum depth of the inlet of the pump can be
calculated using this formula,
S=D+(0.574Q/D^1.5)
Where
S=Submergence in inches
D=Pump bell diameter in inches
Q=Flowrate in gallons per minute
Note: to raise D to the power of 1.5 (3/2) as shown in D^1.5
Take the square root of D and cube the result.
Be sure to calculate from the minimum water level during all
seasons of pump operation.
If the water supply will be located in a confined area such as
canal turn out, and especially if the turnout ends in a cylin-
drical vault, the motion of the pump can result in significant
swirl of the water being sucked through the pump and this
will cause the meter to perform poorly. Be sure to take steps
to keep the water from swirling or meter performance will be
affected.
Booster Pumps before the meter can also cause swirl or an
erratic flow profile. If a booster pump is located before the
meter, it must be located far enough upstream that the flow
profile has a chance to return to normal. Every case will be
different, but we recommend a minimum of at least 10 pipe
diameters after the booster pump and before the meter.
By the very nature of their purpose, booster pumps will also
cause low pressure in the pipe upstream of the pump. If
this low pressure falls low enough, it may open any air vent
upstream of the pump which will cause air to enter the water
stream. In this case, the entrained air will likely cause the
meter to go into an empty pipe state.
10X Minimum
Page 7
AG3000p INSTRUCTIONS
Partially Open Butterfly, Gate or Check Valve
Before Meter (Swirling Flow)
5X
Propeller Meter Before Meter (Swirling Flow)
5X
Partially Open Butterfly, Gate or
Check Valve After Meter
2X
Centrifugal or Booster Pump Before Meter
10X Minimum
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