HYDROLOGICAL SERVICES PTY LTD
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INSTALLATION OF POLYTHENE TUBING AND ORIFICE FITTINGS
A.
General
The polythene tubing - SC078-01 is provided in three hundred 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 orifice fitting is comprised of a moulded polythene threaded cap, an orifice outlet and a
tube fitting. The moulded cap will screw onto a standard 50 nominal bore galvanised pipe.
B.
Orifice Fittings
The site and reference level for the orifice fittings should be resolved before installation
proceeds. The length of tubing from the HS55 to the orifice should not exceed 150 metres. A
suggested method for installation of the orifice fitting is shown below.
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 orifice fitting 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 orifice mounting should be such that it can withstand the forces applied by
the flowing stream and associated floating debris.
C.
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.
D.
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. Refer to diagrams below
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 orifice
fitting, ensuring that both ferrules are in place. Tighten the fitting nut. (Refer to the following
diagram for tightening procedure). Place the orifice fitting onto the mounting pipe and tighten.
Gas Purge Compressor
Issue 7:
16/12/03
© Copyright
HS55 110-02
