A Case study on Rapallo’s provision of services to an Australian gas and power generation company over the past 5 years

In May 2011, our client’s engineering team decided to examine the pressure vessel inspection regime at their LNG plant. This was part of a process review after three years of continuous operation. The examination included the opportunity to revisit the inspection services supply contract. Rapallo was invited to present their inspection credentials to the client’s engineering team. In June 2011, one of Rapallo’s senior managers and one of our experienced inspectors traveled interstate to the client’s head office.

Here they met with the client’s senior engineering team to showcase Rapallo’s engineering & in-service inspection capabilities. Included was a demonstration of Rapallo’s Cloud Based reporting & management program for plant & machinery inspections. Rapallo’s Presentation to the client’s engineering team was very informative and interactive for both the client and Rapallo. In an e-mail from the client the following day, the result of the meeting was clearly evident by this comment made by the client’s engineer;

”Thank you very much for visiting yesterday, we were very pleased with the meeting and the services that Rapallo offer”

Following the successful presentation Rapallo’s inspection team submitted a detailed proposal for conducting in-service inspection of the LNG plant pressure vessels during the planned 2011 shut down to the client’s engineering team. The detailed proposal was accepted and in August 2011 Rapallo commenced the first of several successful annual shut downs at the LNG plant and other projects for the client.

During the first shut down the client discovered a very small/minor ammonia leak in one of the main inlet/suction line valves on the main ammonia refrigeration compressor. The leak appeared to be from a very small imperfection in the valve casting. The lead time for a new valve was several months and installation would take several days requiring shut down of the LNG plant in the middle of summer at the peak supply demand for LNG fuel for the target Power Stations.

LNG Rapallo Valve

Typical Cast Valve

The client asked Rapallo to undertake an engineering evaluation of the inlet/suction valve condition including any potential reasons/causes for the leak and whether the leak needed immediate repair or could be managed until a time of lowest demand for LNG. One of Rapallo’s engineers traveled to site and inspected the valve closely, gathering relevant onsite information including photos and data. Rapallo’s Perth engineering team reviewed the onsite inspection and data from the valve manufacturer’s technical and operational specifications to undertake a Hazard Identification and Risk Assessment of the ammonia leak.

Based on the hazard identification and risk assessment, Rapallo’s engineers were able to provide a Risk based solution and process to safely manage and monitor the minor leak until the next shut down. A formal report was provided to the Client and was accepted as a sound and best practice engineering solution and strategy. The client’s management team were able to safely operate the Ammonia Refrigeration system until the main ammonia compressor suction/inlet valve and associated piping were replaced in the 2012 shut down.

During all of the subsequent shut downs, several of the pressure vessels at the LNG plant presented the client and Rapallo with unique challenges, scenarios and situations for in-service inspection. There was a considerable level of work effort needed to prepare for the inspections and reinstate the vessels after inspection. This combined with the small window of opportunity for internal in-service inspection during the annual shut downs meant that the standard/normal AS/NZS3788 internal inspection process of degassing, purging, complete isolation and opening up for confined space entry needed a special review and assessment to select one or more of the alternative in-service methods described in AS/NZ3788.

Rapallo’s inspection team were able to develop and implement a combination of Acoustic Emissions Non-Destructive Testing with Risked Based inspection and an alternative level of visual inspection that achieved compliance with the WA Occupational Safety & Health legislation and referenced Australian Standards in a cost and time efficient manner.

AE LNG Set Up Rapallo

Typical AE Set-Up

The client operated several other Power Stations and fuel storage facilities that had been in operation for some 6 years. With the successful completion of the previous works, the client requested Rapallo’s assistance to inspect the pressure vessels at each of their power stations as well as undertake fuel facilities audits. On completion of these audits and subsequent works the client was able to demonstrate full compliance with the Western Australian OS&H legislation.

Rapallo continues to provide Inspection, Engineering and NDT services to this very happy client.

Rapallo Asset Management Services

With over 20 years experience in Non Destructive Testing (NDT), Engineering and Inspections, Rapallo has the staff, equipment and capability to take on your shut downs, projects and statutory works.

To discuss how Rapallo can assist you, call Victor Simbile in our Perth office on (08) 6279 0900 or email him at victor.simbile@rapallo.com.au

For more info on Rapallo’s capabilities click here;
Non Destructive Testing (NDT)
Plant & Pressure Vessel Inspection


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