Calibration Columns & Orifice Plates

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For measuring chemical metering pump flow, an H2O Rx Calibration Column (or draw down cylinder) is ideal for calibration checks.

Typically, this is achieved by using a calibration column sized to measure the pump flow rate over a 1 minute (or occasionally 30 second) timeframe.

H2O Rx's Calbration Column range includes:

  • Stock sizes range from 100mL for 6 LPH pumps through to 20L for 1200 LPH pumps
  • Materials for chemical compatibility include:
    • Plastic - PVC and Polyproylene
    • Glass - with a range of wetted end connection materials including PVC, CPVC, Polypropylene, PVDF (Kynar), Teflon (PTFE), and 316SS.
  • Stocked types are typically threaded top and bottom connection. In addition, open topped and dust caps types are available in the plastic ranges.
  • Stocked connection types are typically BSP. In addition NPT in plastic and glass ranges, and socket and ANSI flanged in the glass ranges are also available..
  • Availability is typically exstock.

H2O Rx Calibration Column additional services and equipment include:

  • Modular instalation systems for the large 10L and 20L calibration columns
  • Assistance with sizing, specifications and drawings
  • Custom designed and built Calibration Columns

H2O Rx Calibration Columns

(or draw down cylinder) are designed to be connected to the suction side of a pump. The "drawdown" is timed (typically over 1 minute) and the pumping rate (or flow) can then be calculated.

Features include:

  • Translucent
  • Range of materials for Chemical Resistance - PVC, Polypropylene, and Glass with PVC, CPVC, Polypropylene, PVDF (Kynar), Telfon (PTFE) and 316SS wetted end connections
  • Break Resistant
  • Threaded BSP and NPT for plastic and glass ranges
  • Socket or ANSI flange also in glass ranges
  • Easy to read graduations and lettering
  • Types include top and bottom connections, open top, and dust cap

Modular Installation Systems for large calibration columns.

It is not always practical to install a 10L or 20L calibration column on a dosing skid. These are often field installed meaning your site costs are higher.

H2O Rx has developed an installation system for the large capacity calibration columns.

Benefits include:

  • Modular and quick installation system
  • Reduced site costs
  • Safe and effective for operators

Calibration Column Accessories

Click Here for a brochure.

Dust Caps

Dust Caps are designed for the top connection of our PVC calibration columns to prevent dust and environment ingress while still allowing the calibration column to "breathe".

They should only be used where the top of the calibration column is above the chemical level.

Dust Cap

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Orifice Plates

Orifice plates are designed to provide a known relationship between flow rate and the pressure drop across the plate.

H2O Rx has a standardised parametric design methodology to create an orifice plate design to suit your needs.

Design is automated to simplify the process and in accordance with AS 2360.1.1

Standard sizes range from DN50 to DN1200.

A design certificate detailing Flow vs Pressure Drop and Pressure Drop vs Flow in convenient look up tables is provided with each Orifice Plate.

Click Here for a brochure.


Rotameters are simple flow measuring devices for constant pressure applicaitons. Often used for dilution or carrier water applicaitons, these allow you to set a fixed flow rate of water to dose chemical into when paired with a suitable valve.

In ranges that cover 0.38 L/min to 50 L/min these units should suit most applications.

Click Here for a brochure

Spectacle Blinds

Simple pipeline isolation devices. These can positively isolate and shut down portions of piping for maintenance or during construction.


Spectacle Blind

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Additional Resources


Get it from the Clouds

PVC Calibration Columns.

A drawing detailing this range of Calibration Columns. CAD drawing available on request.

PVC Calibration Columns

Polypropylene Calibration Cylinder Dimensional Drawing.

CAD Drawing available on request.

Polypropylene Calibration Columns
Installation and Operation Manual for the glass upto 10L CVG Series. CVG Series IOM
A dimensional drawing detailing the glass upto 4L CVG Series Calibration Columns with threaded connections. Glass (CVG Series) Calibration Columns
Installation and Operation Manual for the glass ACS Series. ACS Series IOM

H2O Rx Pty Ltd


+61 409 784 236

Last Updated: 18 November, 2021