Testing and assessment

With the life expectancy of existing Pipeline Traps and Closures being extended, it is inevitable that to meet modern day requirements and to assist Intelligent Pigging, in-situ vessel modifications and trap extensions will have to be given consideration. We have the technology and experience to design, manufacture, test and commission modifications to customer requirements, to ensure that vessels meet the latest code requirements and regulations.

We provide technicians and engineers to work in all environments. The site visit can be an integral part of a Planned Maintenance Package or on a call-off basis. Before beginning any work and where applicable, a Scope of Work, Risk and COSHH assessment will be provided. Regular inspection is vital for operators to ensure that the key elements are maintained to the highest safety standards.


We will set up and undertake annually, or when it is deemed necessary, a tailor-made Condition Monitoring and Maintenance Services Program for individual systems, with detailed records of actual work carried out on-site by GD Engineering technicians kept as a permanent record.

These essential services include:

- Maintenance and Refurbishment of Closures and Scraper Signallers
- Seal Surface Refurbishment and Flange Face Machining
- Interlock Systems Maintenance, Pig Trap Refurbishment
- Modification and Trap Extensions
- NDT Inspection
- Wall Thickness Checking
- Full After Sales Service and Spares Backup

Re-engineering and upgrade process

Closure seal faces, which have been subject to highly corrosive operating conditions or poor maintenance procedures, can be refurbished on site even in hazardous areas. A purpose built pneumatically operated cutter is used to re-machine the seal face area, this sealing face area can then be renewed with a permanent leak-free inert surface.
Our facilities include:

- In-situ Machining: up to 1830mm diameters with Internal and Externally mounted machines
- RTJ ‘V’ Grooves
- Joint Rings
- Weld Preps
- Flange Facing
- Finishes: Down to 0.8μm Facing


We will undertake onsite training of operators in the general maintenance and safe operational use of pipeline closures and passage signallers.

Condition Monitoring

To facilitate our proposed scraper trap management scheme we consider it essential to include Non Destructive Testing (NDT) and ultrasonic thickness examination. If required by the client, this inspection can encompass the whole pig trap and not be just confined to the closure.

The inspection report shall be completed on site by a trained GD technician, a copy of which will be left with the appropriate site official. Our engineering department will submit any recommendations deemed necessary to maintain the worthiness of the vessel or the integrity of the closure.

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