Assessing plant life

Furnace heater buildings forming part of a 1960s oil refinery - sold following a successful assessment

An Industrial Member company asked TWI to carry out an independent assessment of several major components in a European oil refinery. Built in the 1960s, the refinery had experienced one major refurbishment and several shut downs. With a view to purchase, the company needed to be assured of remaining life.

A team of TWI engineers visited the site to make visual checks and examine available ultrasonic test results and metallographic specimens. It reviewed all records including in-service inspection results, details on materials used in construction, operational temperatures and pressures. From the data, TWI was able to calculate the service exposure of the major components.

A preliminary remaining life assessment (RLA) showed that only a very small fraction of working life, both in the pressure vessels and of most of the tubing, had actually been used. The engineers discovered minor problems resulting from previous running procedures, and advised on corrective action. They also recommended limited retubing for one of the furnaces where creep cavitation damage had developed due to overtemperature operation.

TWI was able to demonstrate to the client that the plant was still viable, based on an engineering assessment that was completed in less than one week.