|+/- 2% ACCURACY
(+/-0.75% with Flow
(to NIST formerly NBS)
FOR ANY PIPE LINE SIZE
provide adjustable flow
|ACCURACY CAN BE
VERIFIED visually in the field
PFS DESIGN SERVICE
WILL properly locate the
METER CAN BE BUILT OF ANY MATERIAL required
by the specific application
ANY SIGNAL SENSOR
CAN BE USED
C/R Probe; Staff Gauge;
Ultrasonic Level Measurement;
Float Well; Pressure
SPECIAL PATENTED design
US Patent No: 4671119
Halmi- Parshall METERING PRINCIPLE
|Have you ever
specified or used Parshall Flumes in the
Box-to-Pipe way shown here?
|Have you ever considered the errors
this design introduced?
Flow calibrations performed at the Alden Research Laboratory reveal that the customary pipe-to-box-to-flume-to-box-to-pipe design
introduces the flow metering errors shown to the left (of this paragraphs) and greater ones, depending on the geometry of the metering section.
Halmi-Parshall Flume meters eliminate these errors.
|The Main Difference lies in the
INSTALLATION DESIGN SERVICE
Which is part of the metering package supplied by PFS, Inc.
|The importance of this service is underscored by the
fact that the placement of a flume in the pipe line and the geometry and slope of the
upstream and downstream piping play an important role in securing accurate flow
This kind of design service is unavailable from the pipe-to-box-to-flume-to-box-to-pipe design manufacturers. When these manufacturers are approached with placement questions, they disclaim responsibility for the accuracy of the installed meter. Instead, they refer customers to standard published Parshall flume literature, implying that the flumes
described therein are identical to those they are selling. This implication is far from the truth, as proved by the errors uncovered through PFS, Inc. research work (see PFS Publication No: 820-A.) In contrast, PFS, inc. takes full responsibility for the PFS-HF and PFS-HN design.
DIMENSIONS - CAPACITIES - INSTALLATION