BGN Series - Variable Area Flowmeters for Drill Head Cooling Lubricant in Tunnel Boring Machines

Modern tunnel boring machines are commonly located within complex underground factories that require high drilling performance achieved by efficient lubrication, flushing, and cooling. Proper drill-head cooling requires the drilling emulsion to be fed with pressures up to 7250 PSI to the drill head. Variable area flowmeters are used to measure the flow of liquid or gaseous media in pipes and typically use guide-rod floats for visual indication of volumetric flow.

This poses a problem for many high-pressure applications because data collected at the drill head must be collected with a measuring system that can provide an output signal. However, typical variable area flowmeters have weak points that cannot withstand the pressure necessary for applications like tunnel boring.

A Better Solution for Flow Measurement in High-pressure Applications

With the BGN Series variable area flowmeter, the float is kept in place with a revolutionary and robust design through a star guiding system that lacks the weak spot typical of other variable flowmeters on the market that use a guide-rod system.

The BGN series is equipped with a cylindrical measuring tube that can easily be designed for pressures 7250 PSI and up with the use of thick-walled pipes, and includes special features like self-draining, backflow stop, and flow control.

The BGN Series variable area flowmeter measuring tubes come in your choice of 316 stainless steel, PTFE-lined stainless steel, or Hastelloy® C-22. Other materials, including Monel or Tantalum (for especially corrosive applications), are available upon request. The BGN is a purely mechanical variable area flowmeter that consists of a meter tube with end connections, meter orifice, and conical float.

The BGN variable area flowmeter has a robust design that is ideal for applications with rough operating conditions. The measurement is coupled to the mechanical display or output transmitter via an isolated magnet system. The transmitters are available with 4-20 mA HART®, Profibus® or Fieldbus®.