Cold Neutron Radiography of Mechanical Connectors

Abstract

The cold neutron radiography facility at Harwell has been used to investigate possible causes of serious corrosion and mechanical damage to a number of mechanical connectors installed on Shell Expro North Sea platforms. To date, neutron radiography has revealed that the elastomeric 0-ring seals which are designed to prevent seawater ingress into the connector, can be displaced from their groove during assembly, resulting in severe 0-ring distortion and crushing, and thereby causing ineffective sealing. Split 0-rings and incomplete 0-ring compression are features which have also been observed during the course of the neutron radiographic studies. Furthermore, the technique can be used to detect internal joint corrosion located within the relatively thick metal walls of the joints.