The 9909 ATS may be installed on fixed roof, internal or
external floating roof storage tanks and pressurized tanks,
such as spheres and bullets, up to a maximum working
pressure of 50 psi (344 kPa).
Varec recommends fixing/weighing the end of the
averaging bulb to reduce its movement in the tank to
provide more accurate readings. For in-service
installations, a weight (3" in diameter)may be attached to the bottom of the
averaging bulb using a 9/32" (7 mm) diameter connector.
For out-of-service installations, this connector may also be
used to attach to a bracket that is welded to the bottom of
the tank.
Floating roof tanks may utilize a perforated standpipe to
house the 9909 ATS. If a thermowell is to be used with the
9909 ATS, Varec suggests the use of a 2" (51 mm) schedule
40 thermowell. A non-perforated thermowell is generally
oil-filled to improve thermal response to product
temperature changes.
Two 4 " (100 mm) diameter MSS flanges with gaskets are
installed, one on each side of the tank roof. The averaging
bulb ¾ " (19 mm) threaded tube is then screwed into the
MSS flange. This method requires access to the inside of
the tank. An alternate method is to order the unit with an
ANSI flange, which are available up to 4" (100 mm). The
standard lead length of a flange is 4.9 ft (1.5 m); please
consult the factory for any non-standard lead lengths. For
use with floating roof tanks, an additional nylon bush may
also be required.
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