Badger Meter AHL-GD - Hot Tap, High Pressure (2 to 72")" - Manual (Page 3)

User Manual
Page 3 April 2014
INTRODUCTION
The Preso 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 elliptical 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 . Model AHL-GD
comes with instrument shutoff valves with provisions to accept a transmitter
or direct indicating meter . Impact Velocity
Sensing Holes
True Static
Sensing Holes
Figure 1: AHL-GD Ellipse pressure sensing holes
SPECIFICATIONS
Applications Air, liquids and gases
Pipe Sizes 2…72 in . (50…1829 mm)
Pressure 800 psi (5515 kPa) maximum
Temperature 800° F (426° C) maximum
Accuracy ±0 .75% of reading
Turndown Ratio 17:1 with no vacuum effect
Standard Components
T-type head, 316 SS 1/4 in . or 1/2 in . FNPT connection
CS 3000 lb . thread fitting, ASTM A105
316/316L SS Ellipse sensor
Instrument valves (2 per sensor), 1/4 in . or 1/2 in ., CS
316 SS ID tag with wire
150 lb . 316/316L SS sensor flange
CS packing chamber with molythane or graphite packing gland
CS packing chamber flange, 150 lb . with SS cap
316 SS isolation ball valve, NPT threaded
CS threaded nuts and bolts
CS nipples, schedule 40
Reynolds Number
Greater than 75,000 maintains most accurate flow measurements
Less than 75,000 consult factory for estimated results
Resonance
Less than 0 .8 but greater than 1 .2 . If greater than 0 .8, use double support . System shutdown
is required when the double support option is used . Select larger diameter ellipse to avoid
double support .
Table 1: AHL-GD specifications