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I. INTRODUCTION
The Series PFA FM approved fire pump system features the Preso Ellipse primary
flow sensor. Preso's patented elliptical design outperforms and provides greater
accuracy than traditional differential pressure flow measurement devices. This
differential pressure flow meter is designed with a series of ports facing the
upstream velocity pressures, as well as flow sensing ports strategically located
ahead of the trailing edge flow separation.
The multi-ported, self-averaging flow element consists of an el-
liptical shape with two independent flow sensing chambers. The
impact velocity sensing holes (high pressure) are located along
the leading edge and the true static sensing holes (low pressure)
are on the exterior probe side. Series PFA comes with instru-
ment shut-off valves with provisions to accept a direct indicating
meter.
II. SPECIFICATIONS
Applications:
Liquids
Pipe Sizes:
2 to 16 inches (50 to 406.4 mm)
Pressure:
400 PSI (2758 kPa) maximum
Temperature:
Gage
PFA Velocity Sensor
180 °F (80 °C) maximum
250 °F (121 °C) maximum
Accuracy:
±1.75% of reading
Turndown Ratio:
17:1 with no vacuum effect
Standard Components:
Y-type head, brass
Compression fitting;
2” to 5”, brass
6” to 16”, CS with SS ferrule
CS 3000 lb. weld fitting - ASTM A105
316/316L SS Ellipse sensor
Instrument valves (2 per sensor) - ¼” male SAE flare brass ball
Polycarbonate ID tag with wire
Direct reading gage, brass body, 270° arc
Reynolds Number:
Greater than 75,000 maintains most accurate flow measurements
Less than 75,000 consult factory for estimated results
Double Support:
Double support required for the following Systems
Pipe Size
Pump Ratings
4"
400 and 450 GPM
8"
> 2000 GPM
10"
> 2500 GPM
12"
> 3000 GPM
16"
> 5000 GPM
True static
sensing holes
Impact velocity
sensing holes
Содержание PRESO Ellipse PFA Series
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