Failures of plant and equipment have today become unacceptable in terms of high costs, low efficiency, lost production and impact on safety and the environment.
Failures of engineering materials are useful sources of information regarding the interaction of materials, stresses and environments to which the materials have been exposed. As such, the analysis of failures can provide very useful information that may not have been possible to obtain by some form of simulation.
Extensive experience of analysing manufacturing plant failures enables the Enspec team, to apply a detailed and often unique understanding to a client's plant and process conditions - producing detailed analysis of the causes and future prevention of problems.
Failure diagnosis is carried out in our materials laboratory using microscopy and a range of metallographic and analytical techniques, or on-site using non-destructive techniques (where appropriate). Once the cause of failure has been determined, Enspec's expertise can then be applied in the redesigning of components to prevent future failures from occurring.
Our database contains information relating to a wide variety of failures in the following areas:
- Boilers (firetube and water tube)
- Centrifuges
- Compressors
- Food processing equipment
- Heat exchangers
- Pharmaceutical plant and equipment
- Pipelines
- Pressure vessels
- Refrigeration plants
- Shafts / Rotating Equipment
- Storage racking
- Storage tanks
- Structural steelwork
- Weldments
Failure analysis can be carried out for several different reasons:
- To decide whether the failure can be repaired, or, the item has to be replaced.
- To determine whether the failure is due to a design problem, or, is due to operational issues. This information may be useful to decide the responsibility of the designer, the fabricator and the operating company.
- As part of a Continuous Improvement programme to improve the operating life of an item that has failed.
Although Enspec has carried out failure analysis on most of the materials that are used in process plants and packing machines, we have extensive knowledge of the following specialised areas :
- Stainless steels and other corrosion resistant alloys.
The austenitic stainless steels are extensively used in the foods and beverage, chemical, pharmaceutical, personal products and many other industries. As Enspec has clients in all these industries, we have a wide experience of the types of failures that occur. We also have experience with failures in duplex, austenitic-ferritic stainless steels and nickel based alloys.
We have experienced failures caused by 18 different mechanisms with the most common causes being localised corrosion and fatigue.
- Equipment used in edible oil processing.
Enspec has a large number of clients in the edible oil processing industry. So it is to be expected that we have a lot of knowledge on the failures that have taken place in the edible oil industry.
We have been involved in failure analysis work with a large number of plant items including, semicontinuous deodorisers and their associated high pressure boilers, batch deodorisers, hydrogenation vessels, neutralisers/bleachers, vacuum filters, plate heat exchangers, scraped surface heat exchangers etc.
- Firetube/Watertube boilers.
We consider that basic service equipment, such as steam raising plant should always be treated as critical plant items. In the case of boilers, there is a long history of failures both on the fire side and water side.
- Ammonia refrigeration equipment.
Ammonia refrigeration plants are widely used in the food industry, Enspec has carried out investigations into the failures of pipework and vessels. We have particular expertise on ammonia induced stress corrosion cracking in ambient temperature liquid receivers.
Failures can occur for a variety of reasons, but they can be classified into eight main categories.
- Brittle fracture
- Corrosion
- Creep
- Environmentally assisted stress
- Corrosion fatigue
- Fatigue
- Mechanical abuse
- Wear
Some examples of the different types of failures listed above can be seen in the Failure Case Histories section, which provides a summary of a selection of recent case studies conducted for clients.