General Description; Application - Hoffer Flow Controls HP Series User Manual

GENERAL DESCRIPTION

The Hoffer HP Series Profile/Insertion Flowmeter is designed to measure fluid
(gas or liquid) flow in medium to large diameter pipes and provide an output
signal that is proportional to that flow.
The flowmeter is designed to be installed, removed, and orientated without
interrupting fluid flow in the pipeline. A conventional hot tap may be used to
install the flowmeter.
The HP Series Flowmeter consist of a support assembly, turbine rotor, and pickup
coil which provides a pulse output signal that is proportional to the fluid flow.
The support assembly portion consists of a stem, stem housing, handle, and
conduit enclosure. The stem is graduated to aid in insertion to the desired depth
and has a pickup coil located within its interior. The stem housing provides the
necessary sealing action. The handle is used to align the sense head to the proper
orientation. The conduit enclosure may be used as a junction box with
connections to the turbine flowmeter or alternately as an enclosure for a
preamplifier or two wire transmitter.

APPLICATION

The HP Series Profile/Insertion Flowmeter responds to the average velocity
appearing across the well assembly.
To accurately measure the flow of fluid in a large diameter pipe it is necessary to
locate the well assembly at an insertion depth corresponding to the average
velocity. When located at a point other than that corresponding to the average
velocity, a scale factor must be included (see Table B). The effective area of the
pipe, as well as other factors, must be considered in order to predict the pulses per
unit-volume of the flow-metering section.
Since the axis of the rotor may be moved with the handle, it is possible to obtain
information on the swirl present in the pipe. The orientation that produces the
maximum output frequency is the direction of flow.
The velocity may be obtained from the magnitude of the frequency output as this
relates to the feet per second calibration of the well assembly. As the well
assembly is inserted into the pipe, the velocity profile may be measured to
determine the mean velocity point.
HP-208 Page 1 of 17 HP Insertion Meter