NDT team inspect welds on Bahrain reactors
January 1st 2006

Aplanned unit shutdown at a Middle east refinery provided the opportunity for Veritec Sonomatic to carry out high frequency inspection of welds and reactor tray supports.

The refinery, operated by the Bahrain Petroleum Company, has two de-sulphurising catalytic reactors, key to the plant's production. BAPCO decided that a full ND inspection was required to assess the reactor's condition and projected working life.

Veritec Sonomatic sent six teams of three test engineers to Bahrain to provide 24h continuous testing of the 21/4Cr stainless steel clad vessels. All of the weldments were inspected on the 4m diameter and 17m long vessels and tray supports. These included circumferential, longitudinal, petal welds and dome to shell welds.

The method chosen was the time-of-flight diffraction (TOFD) technique in conjunction with Veritec's Microplus analytical equipment which provides immediate analysis and mapping as the non-intrusive testing progresses.

The company says TOFD is a superior alternative to radiography for weld inspection and that it is normally more cost effective than other techniques when all relevant factors including repairs and disruption are taken into account.

It can detect and simultaneously size flaws of any orientation and there is no need for radioactive protection rules; other work can be carried out in the immediate vicinity.

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