Conax helps engineer a custom sensor design that can withstand liquid motion forces inside cold storage tanks to ensure accurate monitoring.

Company: Liquid and Liquified Gas Storage Tank Manufacturer

Challenge: The customer has three tank monitoring challenges for internal temperatures to -200° C in large liquid ammonia, liquid nitrogen, liquid oxygen and liquified natural gas (LNG) storage tanks:

  1. The tank is filled with liquid nitrogen to pre-cool the tank structure prior to filling with the final product. This prevents rapid cool-down and possible structural damage. Sensors are installed in the insulation-filled annulus area of the double-walled storage tanks.
  2. Sensors are installed in the bottom of the insulation-filled annulus area of the double-walled storage tanks to detect leaks.
  3. Some storage tank designs require constant monitoring of the tank liquid.

The customer required an RTD sensor assembly capable of providing the mechanical strength needed to withstand liquid motion forces inside the storage tank, to be immersed in a cryogenic fluid, with a terminal lug for direct attachment to a 0.25″ bolt. Leadwire lengths vary from 119 ft. to 279 ft.

Solution: Conax provided a Type T4 RTD sensor assembly with stainless steel braided leadwire. A 3.50″ long stainless steel barrel encapsulates the RTD element and provides a means to bolt onto a 0.25″ stud. The wire is mechanically crimped within the SST barrel with an internal PTFE boot for the cryogenic service. A Conax MHM5-040- B12-T seals the leads exiting the storage tank.

Impact:  Conax worked closely with the customer’s engineering group to develop sensor designs and specification data sheets to meet all three of their tank monitoring challenges.