By | 2020-10-22

Gamma scanning is an online diagnostic tool that allows for the inspection of industrial equipment without interrupting operations. It is often used in oil refineries, gas plants, and petrochemical plants, such as reactors, to identify production problems.

Advantages of using gamma scanning

Gamma scanning helps companies avoid unscheduled shutdowns that can cost millions in lost production and can be dangerous to the staff working there. Non-urgent problems identified through gamma scanning can be scheduled for maintenance or fixing at a time that suits the production timelines. Gamma scanning can help companies optimize production in this manner.

There are several benefits to using gamma scanning instead of other methods, such as x-rays:

  • Gamma scanning requires no electrical or water supplies
  • The equipment used for gamma scanning is smaller, lighter, and more portable
  • The equipment is also more robust and simpler to use and access
  • The initial cost of the equipment is relatively low
  • Gamma scanning allows for greater penetration

Disadvantages of gamma scanning

Gamma scanning has some drawbacks, which include:

  • Radiation cannot be turned off
  • The equipment must be handled remotely
  • The results have inferior geometric sharpness
  • The exposure times can be longer
  • The radiographs are of a lower quality
  • The sources need to be replaced

Uses of gamma scanning

Companies can use gamma scanning to detect issues in packed and trayed towers. 

  • In trayed towers, gamma scanning can determine items, such as the position of production bottlenecks and the location of displaced or damaged trays. Gamma scanning can also determine the accumulation levels of liquid at the base of the trayed tower. It can also identify the spread and amount of entrainment, weeping, foaming, and flooding.
  • In packed towers, gamma scanning can determine if the beds have been damaged, whether the packed beds are in position, and whether there are any issues in the liquid-vapor distribution. Companies can use gamma scanning to determine if there has been settling of the packing and whether demister distributors and pads are at their correct locations.

Companies can use gamma scanning for pipe scanning to

  • determine the gauge flowing densities,
  • identify blockages
  • discover areas of lost refractory

Another use of gamma scanning is to monitor stationary time to determine flood points, gamin rates, and other hydraulic features.

How does gamma scanning work?

Companies performing gamma scans need access to the vessel’s top to start the gamma scanning process. Gamma scanning involves a collimated beam of gamma rays passing through the equipment to measure the intensity and create a density profile. Gamma scanning allows for detecting mechanical damage, tray flooding, liquid hold-up, and tray dislodgement. The identified problem can then be fixed quickly and safely during scheduled maintenance periods.