Nuclear – working with Pressure

Delta Mobrey offers a range of pressure switches as part of our process instrumentation portfolio.  All our products are used in a variety of industries, from distilleries to heavy industry.  Process instrumentation gives industries confidence that industrial systems are managed and controlled, working within defined parameters which allows for the safety and efficiency of smooth manufacturing.

Nuclear is a prime example of how our process instrumentation products work to control the unseen and manage any potential deviations from the required standards.  Safety and security is always paramount within Nuclear so this is a great example of how our products supply the essential peace of mind.

300 Model Differential Pressure Switch

Application: Detection of sudden increase in pressure inside containment after a High Energy Line (HELB)/ Loss of Coolant Accident (LOCA) event.


Applications details:

The ambient conditions in the containment structure of a nuclear power plants needs to be controlled and monitored to ensure safe working of the power plant. The three-primary objectives of nuclear reactor safety systems are: 1. to shut down the reactor; 2. to maintain it in a shutdown condition; and 3. to prevent the release of radioactive material.

To achieve this, the instruments detecting an HELB or LOCA event must be reliable, accurate and fast acting. It is common to use number of different types of instruments to monitor this type of failure to ensure the important parameters are measured and that there is redundancy in the system.

A typical application is to detect the rapid changes in the ambient pressure within the containment where the primary circuit is housed. Delta Mobrey’s solution, which is installed in a number of containment areas in different NPP, is achieved by ‘throttling’ or slowing the low-pressure side of a Differential Pressure cell via. a small pressure vessel or tank such that the rate of change of pressure is lower than it is through the high-pressure side than the low-pressure side. A sudden change in pressure-due to a high-energy line break (HELB) for example – is detected by the high-pressure side of the DP cell sooner than the low-pressure side and the switch is activated.


The Solution 

A 300 Model Differential Pressure Switch is well suited for such rapid change of pressure applications Features include:

  • IEEE Class 1E (Harsh) qualified (RCC-E K2)
  • RCC-E K3 and K3ad qualified
  • Long term stability
  • Narrow deadband
  • Negligible temperature effect
  • High repeatability (±1% of FS at 20°C)
  • Proven field experience
  • Field adjustable set-point – no special tools required
  • 10 years Market Leading Warranty (with option to extend)


The Results

Delta Mobrey Performance Series 300 differential pressure switches have been employed in several nuclear power plants in Sweden for the detection of rapid change in pressure inside containment since 1990.

If you would like more information about this product, or if you would like more information about our involvement within the nuclear industry check this out here.

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