The T-O-let Fitting has been welded to the desired pipeline location and a 2" gate or ball valve has been installed and pressure tested. A 1-7/8" hole has been hot tapped into the system using a IFT T-1 tapping machine. The "coupon" or cut portion has been held by a retention device on the pilot drill. The "coupon" is retracted above the valve and the valve is then closed, at this point the tapping machine can be removed.
After the tapping procedure is completed, a
magnetic retrieval device is installed onto the
valve and the valve is opened. The magnet is
inserted past the valve to the bottom of the
pipeline where shavings may sit.
Since some flow devices utilize magnetic
components to help calculate the
measurement of flow, it is important to
remove the shavings from the line. The
magnet is then retracted above the valve
and the valve closed so that the retrieval
device may be removed and cleaned.
Insertion of the flowmeter into the pipeline begins by securing the meter to the valve and opening the valve. A seal in the metering device keeps any water flow from escaping, while the paddle wheels are pushed past the valve to a depth determined inside the pipe. The meter is then held in position by three threaded rods. Under high pressure the force pushing against the meter is too great to insert it to the desired depth in the pipe. An inserting tool (IT- #102) must be used to install and retract the meter. Once the meter is installed the wires can be hooked up to a number of recording instruments and monitors.
International Flow Technologies, Inc. Services Division has designed flowmeter
installation machinery capable of installing technical sensing devices, which relay
information to a monitoring station. IFT Services Division has the capability to install
most flowmeter sending devices into pressurized mains, without a shutdown.
IFT can provide flowmeters and/or install your meters without interruption of
service. A number of flowmetering models are available for a wide range of pipe sizes,
temperatures, pressures and purposes.
The most common type of flowmeter generates a frequency which is
proportional to the flow rate. An internal pre-amplifier allows the pulse signal to travel
up to 2000 feet without amplification.
Power to operate the meter is provided by the flow monitor or an external
source. The impeller shaft, o-rings, and impeller bearings are replaceable in the field.
IFT uses flowmeters that feature a closed, six blade impeller design. As the liquid
flow turns the impeller, a low impedance 8V DC signal is transmitted with a frequency
proportional to the flow rate.
The accuracy of flow measurement for all measuring devices is highly dependent
on proper installation and location in the piping system. Irregular flow velocity profiles
caused by valves, fittings, pipe bends, etc. can lead to inaccurate overall flow rate
indications even though local flow velocity measurements may be accurate. A meter
located in the pipe where it can be affected by debris or air in the pipeline may not
achieve full accuracy and could possibly be damaged.
IFT meters are designed to be reliable under the most diverse conditions, but the
following recommendations should be considered when installing the meter to ensure
maximum efficency and accuracy.
1) Choose a location on the pipe where a distance of 10 diameters up-stream
and 5 diameters down-stream of the meter provide no flow disturbance. Pipe bends,
valves or other fittings, and pipe enlargements and reductions should not be present in
this area of the pipe.
2) The preferred location of a meter on a horizontal pipe is on top, or not more
than 45 degrees from top dead center. The meter should never be located at the
bottom of the pipe, as sediment may collect and disrupt accuracy or damage the
meter. Locations off of top dead center will cause impeller friction to increase, which
may affect the meter's performance at low flow rates. Any location is correct for
installations on vertical pipelines.
3) An insertion depth of 1-1/2" for pipe sizes of 2.5" and larger is required for various meter mounting configurations to ensure accuracy.
4) Alignment of the meter to ensure that the impeller rotation is parallel to flow is
important.