Quality Plans

August 31st, 2010

In an increasingly complex world where more and more reliance is placed on technology, the consequences when things go wrong can be financially and economically severe. In the past, if a horse threw a shoe or a bucket got a hole it was just fixed and life carried on. However if a pipeline fails or a safety system malfunctions the results can be widespread and effect lots of people and the environment.

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.

You Must and You Should

August 27th, 2010

In all field of engineering, especially the petrochemical industry, there are a wide range of design and regulatory standards that should be adhered to when designing a pipeline and its component parts.

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.

Safety by Design

August 21st, 2010

When the first of any type of system is designed and installed, it is done to suit the practicality of what is required. Performance is the initial objective and a design is judged by how well it achieves its goals, does it go fast enough? Deliver enough? Is it strong enough?

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.

Right Tool for the Right Job

August 18th, 2010

In any design application one of the key considerations is what material is used to produce a specific item. The material needs to be able to cope with the mechanical stresses that may be imposed upon it, from mechanical shock to exposure to high temperatures and pressures. Equally the application must not be over engineered, utilising a material that is overly heavy or costly for a specific job, otherwise this will simply make the project uneconomic. Designers need to be sure that the material they are selecting is the correct one for that specific application.

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.

Using Sound in Quality Testing

August 9th, 2010

When quality checking pipe fittings and pipework it is sometime necessary to deploy a range of techniques depending on the circumstance and exactly what it is that is being investigated.

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.

Quality Counts

August 3rd, 2010

When it comes to quality of materials, the petrochemical industry can take no chances. A failure of pipelines or pipe fittings such as a flanges or couplings in service can be catastrophic and very costly in terms of damage and lost production.

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.

Better by Design

July 27th, 2010

Most people when asked to design a pipeline would simply draw a pipe from point A to point B. However there is much more to the design of a pipeline than this.

To start with, the pipe has to be correctly sized to cope with the volume flow rate required. If the pipe is too small then it will take more pump pressure to force the required amount of liquid though it. A higher pressure will also require a stronger pipe and pipe fittings. If it is too large then it is just a waste of materials and money.

Another consideration is the temperature of the liquid flowing through the pipe. Although we think of steel pipes as pretty solid things that do not move, in practice the metal will expand when exposed to even relatively moderate temperatures. The result of this is that over a distance there can be considerable movement. As an example a 30m length of steel pipe carrying steam at 150°C will expand nearly 63mm.

To counter this, it is necessary to introduce expansion loops that allow the pipe run to deform and take up this movement. The size and number of these loops has to be carefully calculated to prevent over stressing the welded and flange connections.

We at Chemipetro can supply a wide range of pipes, flanges and pipe fittings made from varying materials such as duplex and super duplex stainless steels to ensure that the pipeline designer can always specify the correct material for the job at hand.

Raising the Standard

July 24th, 2010

It has become accepted that unless we are purchasing something unique, such as a piece of art, we expect it to conform to a set standard and that it will be exactly like all the other units of the same type from the same manufacturer. We also expect that items purchased from one manufacturer will be compatible with similar units from another manufacturer.

This however has not always been the case. In early manufacturing, each component was unique and manufactured to perform a specific job for a particular manufacturer. This was why a ‘fitter’ was called such. His job was to adjust and manufacture the pieces so they ‘fitted’ together.

This caused fundamental problems with compatibility with even simple components such as nuts and bolts, let alone with more complex units such as pipe flanges and pipe fittings.

It therefore became apparent very quickly that there needed to be some sort of national standard to which specifiers could refer to ensure they always got what they required and manufacturers could consult so they could produce a standard compatible product.

This resulted in the following national standards being set up:

BS – British Standards Institute founded in 1901

ANSI – American National Standards Institute founded in 1918

ASTM – A voluntary standards organisation formed in 1898

DIN – The German Institute for Standardisation founded in 1917

Today these institutes publish the worldwide standards for engineering products.

We at Chimipetro manufacture a wide range of pipe fittings and flanges to meet all these standards, so that you can specify the right product in the certain knowledge that it will be compatible with your installation.

Widening the Field

July 21st, 2010

As well as a wide range of pipe fittings and pipe flanges, we at Chemipetro manufacture an extensive range of pipes for use in the petrochemical industry. But this is not all we do as we also manufacture a range of seamless pipe especially designer for use in boilers and heat exchangers.

On first considerations this may seem like it is moving outside our normal field but in the processing of chemicals there is a regular requirement for these. Whilst we are all very familiar with boilers, what exactly is a heat exchanger?

Heat exchangers and boilers are very similar in function in that they are used to transfer heat from one medium to another. In the case of a boiler the heat comes from the combustion of a fuel producing a hot gas. This hot gas is then used to heat a second liquid, which in the case of boilers is water.

In a heat exchanger the process is similar in that heat is transferred from one medium to another, but in this case they are usually both liquids. A hot liquid runs through the primary tube transferring heat to a second liquid on the secondary side. By passing a cold liquid through the primary tube, they can also be used for cooling.

The common link between boilers and heat exchangers is that they are called to handle liquids over a wide range of temperatures and high pressures and that the pipes used to manufacture them must be of the highest standards. So perhaps not so outside our field as you might first think.

To view a wide range of pipe fittings and flanges on their website, visit Chemi Petro’s website today.

The Problem with Biodiesel

July 12th, 2010

It used to be the case that we consumed fuel with no consideration to the fact that one day it would all be gone. Apart from times of national shortage such as wars, there always seemed to be more than we needed.

However over recent years we have perhaps become more conscious of the fact that oil is a limited resource and we have started to look for new ways to provide the fuels which are such an integral part of our modern economy.

In recent years this has seen a big rise in the development of biofuels. These are oils made from plant material and the oil is extracted by ‘pressing” which is a traditional method. However the plant material can be fermented to produce bio-alcohol. These can then be used either as direct fuels or more commonly can be blended to produce biodiesel which produces less toxic emissions but maintains the engines performance.

One problem with producing these fuels however is that they have different chemical properties to mineral oils and can have a corrosive effect on materials used for pipe fittings that are not affected by regular fuels.

Some types of plastic such as high density polyethylene (HDPE) are not affected but polyvinyl chloride (PVC) is slowly degraded. Metals are also affected, with biodiesel having an effect on copper-based materials such as brass as well as zinc, tin, lead, and cast iron. Stainless steels and aluminium are however unaffected.

Chemipetro produce a wide range of pipe fittings and flanges in duplex and super duplex stainless steels which are compatible for use with these new fuel technologies.