HYDROLOGICAL SERVICES PTY LTD
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INSTALLATION OF POLYTHENE TUBING AND GAS CHAMBER ORIFICE GC01
E.
General Description
The G.C.O.1 permits the use of extremely low bubble rates with increased accuracy and near
total reduction of lag between actual level rise and orifice pressure. The polythene tubing -
SC078-01 can be supplied in 100 or 300 metre rolls. It is an extremely durable material that
has been used successfully in this application world wide for many years. The tubing is
flexible, easy to handle and can be cut with a knife.
The copper construction of the GCO1 deters aquatic growth while the plastic insulating bush
prevents contact between the copper chamber and steel pipe.
Bubble rates as low as 40 bubbles per minutes (bpm) can be used on fast rising water levels,
thereby reducing gas consumption by as much as 60%.
The GC01 chamber orifice is constructed of copper and welded to a 2" copper connection . The
connection mates with a 2" plastic insulating bush and is taped for a 1/4" National pipe thread
(NPT) copper Swagelok a fitting which allows adaptability to the existing standard USGS
orifice configuration. The bottom of the chamber include a removable copper screen for
cleaning purposes.
F.
Performance:
The following table summaries the results of comparative tests on the H.S demonstration rig
with water level rising at 9 meters/hr.
Float Operated
Encoder
(Level in mm)
Standard Orifice
100 Bubble/Min
Gas Chamber Orifice
10 Bubbles/Min
Reading
Lag
Reading
Lag
0
0
--
0
--
810
578
232
810
0
1700
1200
500
1700
0
2400
1540
860
2398
2
3600
2294
1306
3588
12
At 3 meters/hr rate of rise the standard orifice still lagged significantly whereas the gas chamber
orifice exhibited no appreciable error.
Gas Purge Compressor
Issue 7:
16/12/03
© Copyright
HS55 110-09
