Site Considerations; Electronics Console Location; Flowcell Location; Transducer Location - GE DigitalFlow GS868 Startup Manual

March 2008

Site Considerations

Electronics Console
Location

Flowcell Location

Transducer Location

1-2
Because the relative physical locations of the flowcell and the Model
GS868 electronics console are important, use the guidelines given in
this section to plan the Model GS868 system installation.
The standard Model GS868 electronics enclosure is a Type-4X
weather-resistant, dust-tight, indoor/outdoor type. Typically, the
electronics console is mounted in a meter shed. When choosing a
mounting site, make sure that the location permits easy access to the
console for programming, testing, and servicing.
Note: For compliance with the European Union's Low Voltage
Directive (73/23/EEC), this unit requires an external power
disconnect device such as a switch or circuit breaker. The
disconnect device must be marked as such, clearly visible,
directly accessible, and located within 1.8 m (6 ft) of the
Model GS868.
The pipeline flowcell consists of the flowmeter transducers and any
pressure and/or temperature transducers employed as part of the
flowmeter system. Ideally, choose a section of pipe with unlimited
access as the flowcell; for example, a long stretch of pipe that is
above ground. However, if the flowcell is mounted on an
underground pipe, dig a pit around the pipe to facilitate installation of
the transducer mechanisms.
For a given fluid and pipe, the Model GS868's accuracy depends
primarily on the location and alignment of the transducers. In addition
to accessibility, when planning for transducer location, adhere to the
following guidelines:
1. Locate the transducers so that there are at least 20 pipe diameters
of straight, undisturbed flow upstream and 10 pipe diameters of
straight, undisturbed flow downstream from the measurement
point. To ensure undisturbed flow, avoid: sources of turbulence in
the fluid such as valves, flanges, expansions and elbows; swirl;
and dips or low spots in which condensed liquid may collect.
2. Because condensate or sediment at the bottom of the pipe may
cause attenuation of the ultrasonic signal, locate the transducers on
the side of a horizontal pipe, where possible. If limited pipe access
necessitates top-mounted transducers and the sound beam path
includes a reflection, shift the transducers to at least 10° off top
center. This will minimize the influence of any sediment on the
reflected ultrasonic signals.
Installation