HYDROLOGICAL SERVICES PTY LTD
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G.
Orifice Fittings
The site and reference level for the GCO1 should be resolved before installation proceeds. The
length of tubing from the (HS23A or HS23DB) to the orifice should not exceed 150 metres. A
suggested method for installation of the GCO1 is shown in (fig1,page 100-03)
The site of the orifice should be positioned in quiet water out of the mainstream to provide
protection. The area should be free of silting and aquatic growth.
The mounting for the GCO1 should consist of a section of 50 nominal bore galvanised pipe
threaded at one end and secured at the appropriate reference level.
The securing of the Gas Chamber Orifice (GCO1) mounting should be such that it can withstand
the forces applied by the flowing stream and associated floating debris.
The immersion of the GCO1 in the water should be at level equal or higher to that of CTF
point ( see fig 1, page 100-03)
H.
Preparation of Orifice Tubing
Do not open the carton or remove the strapping. To prepare the roll of tubing for use, cut a 300
mm diameter hole in the centre of the cardboard carton, retrieve the end of the tubing from the
middle of the coil, then cut the strapping retaining the coil. This method will reduce the
possibility of tangling the tubing. Prevent the ingress of dirt etc. from entering the tubing, by
taping up the ends. At no time should the open end of the tubing be permitted to contact the
soil.
I.
Orifice Tubing
It is recommended that a trench be dug (minimum 600 deep) between the equipment shelter and
the proposed positions of the orifice The trenches should not have any low points in their length,
they should have a continuous fall to the river.
Pull the free end of the coiled tubing to the orifice position laying the tubing in the trench as you
go. Remove the protective tape from the end of the tubing, and push the tubing through the 50
nominal bore pipe mounting. Insert the tubing into the tube fitting on the rear of the GCO1
orifice fitting, ensuring that both ferrules are in place. Tighten the fitting nut first and then place
the GCO1 assembly onto the mounting pipe and tighten the barrel union. (See fig 2, page 100-
04).
Cut the tube at the coil end (tape both ends), ensuring that there is sufficient length to make the
joint at the (HS23A, HS23DB) within the shelter. Check the lay of the tubing in the trench to
ensure that it is free of coils and kinks. Under no circumstances should the tube form hollows
where moisture can be trapped within the tube. Lay the tubing into position in the equipment
shelter as required. Remove the protective tape from the end of river line tube. Insert the end of
the tube into the appropriate river line fitting on the (HS23A, HS23DB) and tighten both
fittings.
Finally, Open the valve to the orifice.
Gas Purge Compressor
Issue 7:
16/12/03
© Copyright
HS55 110-010
