Endress+Hauser has been manufacturing differential pressure (DP) flow devices from its UK base for 25 years. The tried-and-tested technology for measuring flow in a closed pipe remains popular due to its low cost and simple design.
DP flow solutions are made up of two elements: a primary element, which introduces a pressure drop, and a secondary element (a DP flow transmitter) to measure the differential pressure flow. The concept of using a pressure drop to measure flow dates back as far as the 18th century yet still holds up today.
The advantages of using DP flow technology are:
- Well-understood and widely used technology
- Low maintenance
- Suitable for liquid, gas and steam applications
- Cost-effective
- Short delivery times available
Endress+Hauser manufactures a range of primary DP flow devices from its Centre of Competence in Manchester, including averaging Pitot tubes, orifice plates, cone meters and Venturi tubes. As they are manufactured in-house, each device can be tailored to the end user’s exact requirements.
Subsea applications
DP flow remains a particularly popular technology in the petrochemical and oil & gas industries. Known for being stable and robust, it has many possible applications – even under the sea. Endress+Hauser’s DP flow primary devices and expertise have been used to great effect in recent years in subsea gas compression projects. Compression is used to boost the gas flow from offshore fields to processing platforms, accelerating production and ensuring the flow remains stable.
The gas enters the compressor at low pressure and flows out at considerably higher pressure. However, compressors can be affected by ‘surge’, a condition that occurs when the amount of gas being compressed is insufficient for the speed of the compressor and the turbine blades lose their forward thrust, causing a reverse movement in the shaft. ‘Surge can have catastrophic effects on a compressor, so you really want to prevent that happening, particularly when the machine is operating below 1300 metres of seawater!’ says David Knight, Endress+Hauser’s Product Marketing Manager for Temperature and DP Flow.
Endress+Hauser has designed and built Venturi tubes for anti-surge control systems, utilising new technology and processes. The Venturis are manufactured from super duplex stainless steel, providing corrosion resistance and high mechanical strength. Hot Isostatic Pressing (HIP) is used in place of traditional forging to produce the Venturi body in one piece. The priorities are to produce robust and maintenance-free instrumentation. ‘The system’s designed so that one instrument can be on standby while the other is working,’ explains David Knight. You can bring the whole module out from the seabed but that’s not something you want to be doing regularly!’
Subsea gas compression projects have been proven to massively increase the amount of gas recovered from underwater reservoirs, extending the life of existing offshore gas fields. The technology also significantly reduces energy consumption and carbon emissions.
For more information about DP flow solutions from Endress+Hauser,
call 0161 286 5050 or visit https://eh.digital/dp-flow_uk