July 30th, 2010
How lengths of pipe and pipe fittings are actually connected together would seem, on the face of it, to be a relatively simple exercise but in fact it is a very complex issue.
It is possible to use pipe flanges, but this is an expensive option and is really only suitable for situations where the pipework has to be dismantled for maintenance, as all bolted flanges introduce a weakness.
It is possible to use a threaded connection where the end of one pipe is screwed into the end of another pipe. This method is commonly used for smaller pipe sizes. However the cutting of the thread reduces the thickness of the pipe material and so again introduces a weakness.
The preferred option for joining pipe lengths is a welded joint. But again there are different options depending upon the application. The most common type is the butt weld. This is a connection between two pipes of the same size. The end of each pipe is bevelled so that when the two ends are placed together a V is formed. The pipes are then welded around this V.
However in situations where there are high pressures and the flow characteristics are important, a socket weld can be used. Here one of the pipes has a larger collar which fits over the other pipe. The weld is then done on the outside. These are easy to use especially on small bore pipes.
Whatever type or pipe connection you propose to carry out, we at Chemipetro manufacture a wide range of pipe fittings and pipe flanges to meet all your requirements.
Tags: Flanges, Pipe Fittings, Pipe Flanges, socket weld
Posted in Pipe Flanges | No Comments »
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.
Tags: Flanges, Pipe Fittings, Pipe Flanges, Super Duplex
Posted in Pipe Fittings | No Comments »
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.
Tags: Flanges, pipe fitting types, pipe fittings pipe flanges
Posted in Pipe Fittings | No Comments »
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.
Tags: Flanges, pipe fitting types, Pipe Fittings, Pipe Flanges
Posted in Pipe Fittings | No Comments »
July 18th, 2010
We at Chemipetro produce a wide range of pipe fittings and flanges manufactured from duplex stainless steels, But what exactly are these types of steels and why use duplex steel rather than ordinary steels?
To answer these questions it is necessary to understand what exactly stainless steel is.
Ordinary carbon steel is strong and as such has many applications. However it has one draw back, it rusts when exposed to air and moisture. Under these conditions a film of iron oxide is formed which causes the corrosion to accelerate and more iron oxide to form.
To prevent this happening, chromium is add to produce an alloy. This was first developed in 1821 by Pierre Berthier, a French metallurgist. However these first stainless steels were too brittle to be of much practical use. It was not until the early 1900’s that a process was developed for producing a practical stainless steel.
Stainless steel resists corrosion by the chromium forming a protective layer of chromium oxide. This layer is impervious to water and air and so protects the metal beneath.
Stainless steels are categorised by their crystalline structure, the most common being austenitic steels which contain nickel or manganese as well as the chromium. However these steels can be expensive especially with the higher grades which also contain molybdenum.
Duplex steels have a mixed structure of austenite and ferrite, giving them improved strength over austenitic stainless steels and improved resistance to local corrosion. This means that for a given strength, castings can have reduced thickness and weight, thus making them cheaper.
Tags: Duplex, duplex stainless steels, Pipe Fittings, Super Duplex
Posted in Duplex | No Comments »
July 15th, 2010
To the uninitiated a flange is a flange. However to the pipeline designer the use of a particular type of flange for a specific situation is critical. The use of the incorrect type of flange can lead to restrictions is flow rates, turbulence in the flow leading to cavitation and even premature failure. This can be catastrophic if it occurs in the wrong place at the wrong time. Also different types of flanges, although similar in appearance may be used for totally different applications.
A weld neck flange is probably the most common type of flange fitting for connecting two sections of pipe and is particularly used for high pressure installations; it consists of a round plate with the central bore the size of the pipe. They also have a collar which increases in thickness at the base of the plate. They are connected to the pipe by welding the collar end on to the pipe. They are recommended for installations which require a robust pipe joint especially if it is subject to temperature variations.
However there is also a long weld neck flange. Although this is similar in concept is has a considerably longer collar and is used for a completely different application. This type of flange is used where a nozzle is required for a pipe.
We at Chemipetro produce a wide variety of pipe fittings and flanges to ensure that you always have the correct specification of fitting for any specific application.
Tags: flange, Pipe Fittings, pipe flange, weld neck flange
Posted in Pipe Flanges | No Comments »
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.
Tags: Flanges, pipe fitting, Pipe Flanges, Super Duplex
Posted in Pipe Fittings | No Comments »
July 9th, 2010
When designing a pipe run the question is how much fluid can be pushed through a pipe at a given rate? The answer is subject to many variables, however one of the key criteria is the pressure at which the liquid is pumped.
If a high pressure is used then a higher flow rate for a given pipe size can be achieved, and smaller pipes mean less cost in materials and installation. However a pipe is only as strong as its weakest point and this is at the joints.
In continuous pipe runs, joint are usually achieved by welding. Welded joints have their own problems, but they are cost effective and produce a continuous pipe run.
However at some point it will be necessary to include a fitting such as a valve or a pump into a pipeline. Valves and pumps require maintenance and at some time will have to be taken out of line to be replaced. If they were welded into position then this would be a very difficult and time consuming process, as the joint would have to be physically cut and re-welded afterwards. This is where a flange is used.
A pipe flange is a way of terminating a pipe run with a flat face. The pump or valve will also be provided with a flange. These two flanges can then be bolted together with a gasket between to make a joint which can be easily dismantled.
We at Chemipetro produce a wide selection of pipe flanges to suit varying pressures and configurations of pipework making life easier for the pipeline designer.
Tags: Flanges, Pipe Flanges, pipes
Posted in Pipe Flanges | No Comments »
July 6th, 2010
As well as a full range of flangesand pipe fittings, we at Chemipetro can supply a wide range of pipes and tubes to meet any need. Yet the engineering technology of pipes and pipe fittings has not always been the complex technology we know today.
From the earliest beginnings of civilisation, man has had a need to move liquids from one place to another. At first this would have been water for irrigation of crops and achieved by digging simple channels to direct the water flow. Later these water channels became more sophisticated by using stone to create water courses. Probably the most recognisable of these would be the magnificent aqueducts constructed by the Romans. These could be use to bring water for miles across difficult terrain. They were however difficult to construct. A simpler and more cost effective technique was required and also something that could be used on a smaller scale.
A solution was found with the development of wooden pipes. Initially tree logs were used that had a hole bored along the length of them. Later a method using staves and metal hoops was used, similar to the construction of a continuous barrel.
However with the development of industrial processes, the need for stronger and more durable pipes lead to the development of better materials and techniques for producing pipes and pipe fittings. With the development of the petrochemical industry came perhaps the most testing demand of pipe technology including the development of special stainless steels such as duplex and super duplex.
We have certainly moved a long way from mud ditches and tree logs.
Tags: Duplex, Flanges, Pipe Fittings, Super Duplex
Posted in Super Duplex | No Comments »
July 3rd, 2010
The petrochemical industry is well known for its use of the highest grade materials and equipment. The consequences of failures or mistakes can have a significant impact, not least on the environment. The recent events in The Gulf of Mexico are a timely reminder of this fact. We at Chemipetro understand this and so all of our products use the highest quality materials such as duplex and super duplex stainless steels.
When sourcing a supplier, you should ensure they have a commitment to quality, ideally with full traceability of all their pipe fittings and flanges, from the procurement of the raw materials, through the manufacturing process, to the final dispatch to the customer. Every stage of the production process should be monitored and recorded as part of a quality control process.
This sort of traceability ensures a supplier is able to meet the exacting requirements of their clients to ensure that the highest standards of materials and installation are attained. In this sort of industry, quality must be taking seriously and by upholding such high standards, the environment can be protected from failures.
At Chemipetro, we are also the UK’s largest material and fittings stockholder serving the oil industry worldwide, ensuring that the materials our clients require are available exactly when they need them. Should problems arise we can provide a 24 hour emergency call out cover to give our clients reassurance in times of difficulty. Our quality control process complies with BS EN ISO 9001, which is fully approved by Lloyds Register Quality Assurance and means we can help meet the world’s energy demands.
Tags: Duplex, Flanges, Pipe Fittings, Super Duplex
Posted in Duplux | No Comments »
