It is at times like this that it is necessary to trace back to the cause of the problem, not to allocate blame, but to find out what went wrong and ensure it does not happen again. A good example of this is air crash investigations. They are there to find out what failed and check if it may be a risk to other aircraft of the same type.

These investigations require traceability of all components in any system. In pipelines, if pipe fittings or pipe flanges fail it is necessary to trace the source of those components to see if there was a manufacturing fault.

For the overall project the documentation on the procurement of components will form part of the project quality plan. This document is built up over the lifetime of a project and will include details from inception, design, installation and testing. It will form an invaluable tool to the maintenance personnel and can assist if things go wrong.

We at Chemipetro place a high value on quality control and can provide all the necessary documentation, test result and certification for all products we supply to ensure that our clients can meet their quality plan requirements.

However there is a significant difference between what it is legally required to carry out and what is advisory and it is important for the pipeline designer to know the difference between the two.

The Pipeline Safety Regulations are mandatory and legally must be adhered to. However apart from setting general standards they do not stipulate how they are to be complied with. That is the responsibility of the designer and the pipeline operating company.

Design standards on the other hand such as British Standards are advisory documents. They stipulate what is good practice and what the common standards should be to ensure compatibility of components between manufactures such that pipe fittings from one manufacturer will fit with pipe flanges from another manufacturer. They also set the standards for materials such as duplex and super duplex stainless steels so that the purchaser can be assured of the quality of the material being purchased.

At Chemipetro we manufacture a wide range of pipe fittings and component parts to internationally recognised standards.

However they are not meant to deter design innovation and development. So a new component can be used even if it does not specifically meet the standards as set down in a related British Standard provided it can be provided that it does not reduce recognised safety standards in operation.

So although the designer must adhere to regulations, they can develop new ideas without unnecessary constraints.

As a result of these high standards of material, the petrochemical industry generally has a good safety record considering the millions of litres of dangerous fluids and gasses that are processed each day. However, as witnessed by recent events in the Gulf of Mexico, even in the best run worlds things can go wrong.

The Pipelines Safety Regulations, recognise this fact and specifically states under item 12 that before any fluid is allowed to flow in the pipeline the pipeline operator must make specific provision for dealing with:

a) the accidental loss of fluids from the pipeline

b) defects or damage to the pipeline

c) any emergency effecting the pipeline

The pipeline operator must therefore have a safety regime in place that can deal with any type of emergency that may arise. This can be expensive if it is necessary to hold in stock replacements for each type and size of pipe fitting used in an installation.

Therefore in order to assist our clients to meet this obligation, we at Chemipetro offer a 24 hour emergency breakdown call out service. We also hold in stock a wide range of pipes and pipe fittings so that any problem can be dealt with as speedily as possible.

Very soon, problems are identified. These may be problems with performance or they may be problems with safety. It becomes apparent that if a design is to be repeated and adapted, but without repeating mistakes, then some form of written design or safety standard is required.

With the pipeline industry in the UK these are ‘The Pipeline Safety Regulations 1996’. These were enacted as part of the ‘Health and Safety Act’ of 1974.

These regulations cover the design principles required for any pipeline used for conveying gas or fluids, which is not a drain or part of a heating system, and refers particularly to fluids considered ‘dangerous’, which relates to the petrochemical industry.

Part II item 7 specifically states that the pipeline must be designed so that maintenance and inspection work can be carried out safely.

One way of achieving this is to ensure that joints with bolted flanges are located at suitable locations to allow the critical sections of the pipeline to be dismantled. Also, suitable pipe fittings are provided where required such as isolation valves, to ensure that sections can be isolated and drained for working.

We at Chemipetro supply a wide range of flanges and pipe fittings to ensure that your design will comply with the safety regulations.

For example, in the design of heat exchangers it is necessary that the material is not only strong and can withstand the high temperatures and pressures to which it will be exposed, but it is also important that it has good thermal conductivity characteristics. Also, in the petrochemical industry the material must be resistant to corrosion from the various chemicals that it will handle.

Super duplex steel is an excellent material from this stand point. Although it may be more expensive per tonne than ordinary steels, its corrosion resistant properties will ensure it requires less maintenance. Also, it has a low co-efficient of thermal expansion which means that where it is used in applications such as heat exchangers, it will be under less mechanical stress.

We at Chemipetro produce a wide range of pipes, pipe fittings and flanges from super duplex stainless steel and can meet whatever design features your design may require.

There are however two fundamental problems with any sort of glued joint. The first, the joint is only as strong as the glue itself. To help overcome this with welded joints the ends of the pieces are shaped to form a V. This gives the weld a greater surface to form on and so make the bond stronger.

The second problem is that any glued joint is permanent and does not allow for anything to be dismantled should maintenance be required.

To dismantle a joint it should be connected by a removable fastening. This is where the humble nut and bolt come in. By providing flanges on the end of a pipe or a pipe fitting, and by bolting the two flanges together, a strong but removable coupling can be achieved.

But what sort of nut and bolt should be used? In concept they may all be the same but in practice they can be very different, from a simple threaded rod which is cut to length, to a 12 point ferry head unit. The choice of nuts can also be bewildering from the simple hexagonal to a bi hexagonal 12 point self locking type.

Whatever your need we at Chemipetro can provide a wide range of fastenings to meet your specific requirements even if it is a non standard and unique type.

Oil is becoming a scarce commodity and at some time in the future it will be necessary to develop other types of energy sources which can be used as fuels. These alternatives however will provide their own technical problems and challenges which will have to be dealt with.

One such fuel could be hydrogen, which may become a major fuel in the next 50 years. If this was to happen then it would be necessary to develop large scale production, storage and transport infrastructure for this.

However when hydrogen comes into contact with steel it can have a deleterious effect. Hydrogen atoms are the smallest atomic structure and are small enough to penetrate the crystalline structure of steel. This can cause the steel to become brittle and develop fractures. Also, when exerted to high pressures, pockets of hydrogen can develop causing the steel to fracture.

To prevent this happening it is currently necessary to introduce a barrier layer to prevent the hydrogen coming into contact with the steel. Other techniques and materials will also have to be developed so that these systems can be easily manufactured on the scale which will be required.

So in the future a duplex pipe will no longer be a simple steel tube but will have to be in itself a sophisticated piece of engineering.

Whilst Liquid Penetrant Inspection can detect flaws in the surface of a material and Magnetic Particle Inspection can indicate flaws within a material, they cannot identify the thickness of materials and particularly when a component has been in use they cannot identify internal corrosion.

For this it is necessary to use a technique called Ultrasonic Inspection. As its name implies this uses sound to detect flaws. An ultrasound transducer is passed over the sample to be inspected, emitting sound waves from 0.1MHz up to 50MHz. As the sound waves hit any irregularity or the far side of the material they are reflected back. The detector picks up these reflections and the time taken to receive them indicates the distance travelled and hence the thickness or location of the flaw.

This is a particularly useful method to use on pipework or pipe fittings that are already installed as it is possible to determine exactly how thick the wall material is and therefore how much corrosion has taken place.

An alternative method is to locate the detector on the inside of the sample. Here the sound is attenuated by the material and any hidden defects will determine how much the sound is attenuated by.

At Chemipetro we can employ all these quality test procedures and also assist with diagnostics for existing installations with our 24 hour call out service.

Testing samples to destruction will give an overall indicator of how the design of a particular component will perform when exposed to high levels of stress. This confirms if the materials used are up to the task or if there is any weakness in the design. For example, if flanged joints or pipe fittings will perform as required when in actual use.

However, whilst this type of testing may be used to confirm the design of a component it is no use for ensuring the quality of the production run of components. For this it is necessary to use a test that does not actually break the component.

At Chemipetro we use a number of different techniques to ensure the quality of the pipe and pipe fittings we manufacture. One such technique is Liquid Penetrant Inspection.

Here the sample is washed with a liquid containing a special dye and left to soak. The excess material is then removed and a developer applied. When exposed to a high intensity or ultra-violet light, cracks or flaws in the material are visible. The advantage of this system is that it is quick to carry out and can be applied to no ferrous material as well.

These test procedure ensures that product quality is not something that is left to chance but can be assured across the product range.

It is therefore important that all materials are rigorously tested before they are dispatched, as small irregularities in the crystalline structure of the steel can cause fractures, which in turn cause the material to fail when subjected to high pressure and temperatures. It is important to detect these irregularities and specialist detection techniques have to be used.

One such technique is Magnetic Particle Inspection. At some time almost everyone will have carried out an experiment at school where a sheet of paper is laid over a magnet and then iron filings sprinkled over the paper. The iron filings will then align themselves to display the lines of the magnetic field.

Magnetic Particle Inspection is similar in principle, albeit more sophisticated. The part to be tested is subjected to an electromagnetic field to magnetise it. It is then coated with iron oxide either in powder form or in a liquid suspension. Any irregularities in the steel cause an irregularity in the magnetic field, which can be seen in the patterns in the iron oxide. These irregularities can indicate possible faults in the material which can then be investigated further.

At Chemipetro we supply quality materials such as pipe flanges, and we can carry out several specialist testing techniques on critical parts including Magnetic Particle Inspection to ensure the quality of our products.