The requirements for both fabrication and maintenance vary according to the location of the works.
Onshore, the standards are well established. There are few environmental hazards that are not easily over come
Offshore, because of the environment and also because the processing all takes place in a confined space the safety standards are often onerous and the fabrication requirements of the highest order. The induced stresses from waves and wind make it necessary to have a very high standard of both design and construction. The materials are usually of a high strength and are frequently quite thick; this necessitates care in the choice of welding. the inspection standards are also of a high standard.
Sub-sea, is a whole new ball game. Some welding and NDT takes place in the water itself and some is carried out within a habitat. Both environments are stressful for the operators. The maxim 'one hand for yourself and one for the job' sums up the situation where the diver is always aware of the dangers and often the work is of a secondary nature. Many problems, both physiological and work-wise, increase with the depth of the operation. Controls and procedures must be implemented to maximise safety and provide satisfactory work methods. Supervision from both a welder safety and health aspect is important, inspection of the work is usually made remotely from the surface.