ONICON F-1100 Series - Manual (Page 18)

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Turbine Flow Meter Manual 05/14 - 0721-3 / 13518
Page 18
fully withdrawn. Usually a gentle twisting motion while withdrawing the meter will clear any
obstruction and permit the meter to withdraw completely. (Excessive build-up on the stem may
require the hot tap ‘O’ ring to be lubricated with silicone.)
Continue to hold the meter in place after the valve is completely closed to prevent the turbine
assembly from slipping back into the valve body. Slowly unscrew the hot tap adapter from the
valve. Once the adapter is loosened, allow pressure to vent from inside the hot tap adapter before
removing it from the valve. There will be a small amount of water inside the hot tap adapter. A
small container can be held under the valve to catch any spilled water. Once the meter has been
moved to its new depth, tighten the position clamping nut. Next, place several turns of electrical
tape around the stem just above the clamping nut so that at a later time, when the meter is
removed for service, it can be easily replaced at the same depth.
First support the flow meter against the pipe pressure
by holding the electronics enclosure firmly in hand
BEFORE loosening the position clamping nut. The
effort required is the same as that required for insertion
of the meter and should be calculated according to the
formula in section 3.4 covering insertion of the meter.
This effort will be 0.11 times the pipe pressure. If your
footing is not secure, or if your ability to hold the
meter is limited for any reason, DO NOT loosen the
clamping nut.
SLOWLY loosen the position clamping nut and
carefully and slowly allow the pressure to force the
meter out of the pipe. This is not at all difficult, but you
must not let go of the meter until it is fully withdrawn
into the hot tap adapter. Do not attempt to close the ball
valve until you are certain that the turbine assembly is
fully withdrawn into the hot tap adapter.
A common cause of damage to meters comes from
accidentally closing the valve and crushing the turbine
assembly. To avoid this, gently rotate the meter by
swinging the electronics enclosure back and forth
(twist the stem, do not bend it) while you slowly
close the valve. If the valve touches any part of the
meter, you will feel it as you are moving the meter. If
the valve touches anything, it means the meter is not
WARNING
In hot water systems, even a small amount of water can cause serious personal injury. Use extra
caution when working with hot water meters.
!
Position
Clamping Nut