Primary Devices for Open Channel Flow Measurement

FEATURES:

  • The Palmer-Bowlus constricts the flow vertically and horizontally and can be molded to be inserted into an existing half-round pipe.
  • The Parshall flumes constrict primarily horizontally, and are design for rectangular or trapezoidal channels.
  • “H” flumes attach to the ends of pipes where the water is free-falling.

Flume Product Description

Global Water offers water flumes constructed of high quality polyester resin and fiberglass. These flumes are durable, highly accurate, and easy to install.

Global water offers primary device flumes that constrict an open channel’s flow either horizontally or vertically or both. Once the flume flow is backed up behind the constriction, there is a defined relationship between the upstream water level and the open-channel flow through the constriction. This relationship can be determined either by an equation or a look-up table.

Global Water offers three standard molded flumes: the Palmer-Bowlus Flumes, the Parshall Flumes, and the H Flumes.

Global Water offers three standard molded flumes: the Palmer-Bowlus Flumes, the Parshall Flumes, and the H Flumes.

  • The Palmer-Bowlus constricts the flow vertically and horizontally and can be molded to be inserted into an existing half-round pipe. 
  • The Parshall flumes constrict primarily horizontally, and are design for rectangular or trapezoidal channels. 
  • H flumes attach to the ends of pipes where the water is free-falling. 

Flume Installation Overview

For a flume to work properly, there must be freely flowing water out of the flume.  The flow cannot be backed up downstream or the reading will be erroneous and misleading.  Make sure that you have free-flowing water without major inflows downstream of the flume.  The open channel flow measurement can be made by using an open channel flow monitor, a water level logger, a float in an adjacent stilling well, or by an ultrasonic sensor.

Flume Options

Palmer-Bowlus Flume
U shaped channel flume specifically designed for monitoring flows in pipes.

Parshall flume
Industry standard rectangular flume used to monitor streams and channels.

H flume
Used to monitor free fall outflow from pipes or channels when a Palmer-Bowlus or Parshall Flume will not work.

FLUME ACCESSORIES

Flume-SWP2 2 inch Stilling Well Port (PN# 01-320)
Recommended for flumes 8 inches and over in size.  All stilling well ports will be on the left hand side, facing down stream, unless otherwise specified.  A 2 inch stilling well is required for use with submersible sensor.

Flume-SW2 2 inch Stilling Well (PN# BP0000)
2 inch Stilling Well for use with the 2 inch stilling well port.

Flume-SWP1 1 inch Stilling Well Port (PN# 01-729)
Recommended for flumes under 8 inches in size.  All stilling well ports will be on the left hand side, facing down stream, unless otherwise specified.  A 1 inch stilling well is required for use with submersible sensor.

Flume-SW1 1 inch Stilling Well (PN# BP1000)
2 inch Stilling Well with a 1 inch adapter for use with the 1 inch stilling well port.

Flume-SG Staff Gauge (PN# 01-004)
All staff gauges will be in inches unless otherwise specified.

Flume-BT Bubbler Tube (PN# BP1100)
1/4 inch OD stainless steel.

Flume-SW8 Attached 8″ Stilling Well (PN# BP1050)
All stilling wells will be on the left hand side, facing down stream, unless otherwise specified.

Flume-WW Wingwalls (pair) (PN# 01-003)
45 degree angle flat wing walls.

Flume-CAC Concrete Anchor Clips (PN# BP1150)
Charge is per clip, the number of clips varies with flume size.  Example Parshalls over 12 inch normally require 8 clips.

RELATED PRODUCTS

FC220 Open Channel Flow Monitor
Monitor and display total and current flow, datalogging options available.

WL16 Water Level Logger
Record water level and using a depth to flow table convert the data into flow data.

FP111 Flow Probe
Water velocity probe for determining open channel flow.