September 30th, 2010
Designing a pipeline is not a simple matter of a tube from A to B. The material that the pipe is made from has to be selected as suitable for the medium being moved. Some chemicals and gasses can be very corrosive to certain metals and so it is important that the pipe and the pipe fittings are specified correctly.
Another factor to be taken into consideration is the temperature and the pressure that the liquid or gas is to be transported at. Lower temperatures and pressures exert less stress on a system but some materials will not flow properly if they are not at higher temperatures or pressures.
Higher temperatures and pressures exert greater stress on pipe fittings and flanges requiring them to be manufactured to higher standards. This is reflected in the various manufacturing standards that are available. The most common ones are ANSI and BS standards. Which type the pipeline designer chooses will also be determined by the pressure standard required, where the unit is located and to what it is being connected. It is no good connecting an ANSI flange to a BS standard flange.
There are also special standards such as API which apply particularly to high pressure pipe fittings and flanges which may be found in such locations as well heads whereas ANSI standards are for the pipeline itself.
Whatever standard of pipe fitting you require, we at Chemipetro manufacture a full range of pipe flanges and pipe fittings to a wide range of standards so that the pipe designer can always be sure of finding the correct product for the application required.
Tags: ANSI Flange, BS flange, Pipe Fittings, Pipe Flanges
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September 27th, 2010
At Chemipetro we manufacture a range of pipe flanges that take different gasket materials to suit any pressure application.
There are two main types of gasketed flanges, the raised face type and the ring type.
The raised face flange, as its name implies, is manufactured with a raised section which will mate with a similar flange on the other side of the joint. A flat gasket is sandwiched between the two faces to ensure a tight seal. The face of the raised section is textured to ensure a tight grip on the gasket.
In the past, these gaskets used to be made of asbestos, but these days are made from non toxic materials. These flat gaskets may also be of a spiral wound type with a metal filament filled wound into the disc. This deforms when compressed between the two flanges to form a stronger seal.
The second main type of gasketed flange joint is a ring type. In these types of flanges there is a circular or octagonal groove cut in the face of the flange. A metal gasket is then placed in the groove and again deforms to make a seal when the two flanges are bolted together. The flange faces may touch but do not form part of the pressure seal. The advantage of this type of flange connection is that the gasket does not take any of the transmitted loads between the flanges.
It is therefore possible to ensure that the correct flange type is selected and also to the correct standard for the specific application.
Tags: flange, Flanges, gaskets, Pipe Flanges
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September 24th, 2010
The basic definition of a pipe flange is a pipe fitting that allows two sections of pipe to be bolted together.
In concept pipe flanges are very simple, consisting of a flat ring with the inner aperture the size of the pipe it is to be fitted to and holes drilled around the circumference of the ring, which allows two flanges to be bolted face to face.
However this is where the problems arise, for no matter how well machined they are, the mating surface of a pipe flange is never perfect and can have microscopic irregularities. When the two flat plates are bolted together these imperfections can cause problems.
All pipelines operate under pressure, the amount of which varies depending on how close you are to the pumps and what pipe fittings are in between. Any restriction to the flow such as a bend or a valve will cause a reduction in the pipeline pressure, also there will be friction losses the longer the pipeline is. Therefore to overcome these losses it is necessary to pump the medium at a high pressure.
This pressure can cause a simple face to face flange connection to fail and the joint to leak. Therefore, in order to prevent this, it is necessary to introduce a sealing ring between the two flange plates. This gasket ring deforms and seals any imperfections. However there are many different types of gasket depending on the amount of pressure the pipeline will be exerted to.
At Chemipetro we manufacture a range pipe flanges that take different gasket materials to suit any pressure application.
Tags: Flanges, Pipe Fittings, Pipe Flanges, pipes
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September 21st, 2010
At Chemipetro we manufacture a range of pipe fitting and flanges in various specialist materials such as duplex and super duplex stainless steels to ensure the pipeline designer can always specify the correct part.
But pipelines are not just about pipes and pipe fittings. Perhaps the most important piece of equipment in any pipeline is the pump. Whilst there are some systems which are gravity or thermally driven, these are usually only local systems. To get a fluid or gas to go against gravity requires a pump.
Where the pump is located in a system is crucial. It may seem obvious that a pump has an inlet side and an outlet side but the flow characteristics either side of the pump are very different.
A pump is designed to produce pressure on the discharge side to overcome any losses in the pipeline introduced by bends or pipe fittings. The inlet or suction side however produces only enough pressure to draw the medium into the pump. To overcome this discrepancy it is usual to install a reducer on the feed to the pump. The flow of the medium remains the same but the reduction in size increases the pressure.
The correct type of reducer has to be installed as an incorrect installation can cause bubbles to be drawn into the pump of sludge. Sludge can cause the pump to stall. In extreme cases bubbles can also cause this, but more generally they will break up and produce cavitation which will cause damage to the impellor blades.
So, the right type of pipe fitting in the right place is crucial.
Tags: Flanges, Pipe Fittings, Pipe Flanges, pipes
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September 18th, 2010
Changes in sizes of pipelines require pipe fittings called reducers. There are two types, concentric and eccentric. In principle they are similar with one end the size of the smaller pipe and the other end the size of the larger pipe. The difference between the two is that in a concentric reducer the centre line between the two ends is along the centre line of the pipeline whereas in an eccentric reducer the line of the smaller pipe is offset so that one side of the fitting is straight.
This sounds like a minor difference but the wrong type of reducer used in the wrong location can introduce problems that affect the efficiency of the pipeline and in extreme circumstances even cause it to fail.
If installed in a vertical application then the type of reducer used does not matter. It is when they are installed in a horizontal pipe run that the type used becomes important. A concentric reducer will introduce a step in the top and bottom of the pipeline causing gas bubbles to accumulate in the top of this step or sludge in the bottom. If these break free they can cause problems with equipment downstream.
The answer is to install an eccentric reducer with the flat side to the top when the liquid contains gas bubbles and the bottom when it contains sludge. Now the impurities will simply flow along the pipe and not cause a problem.
At Chemipetro we manufacture both concentric and eccentric reducers as well as other pipe fittings and flanges to make sure you have the correct part for job.
Tags: Flanges, Pipe Fittings, pipes, reducers
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September 15th, 2010
In the design of all pipelines there will come a point when it will be necessary to decrease or increase the size of the pipe. It sounds a simple enough task, but how it this to be achieved? In the most basic of installations it would be possible to simply cap off the end of the larger pipe fitting, cut a hole in it the same size as the smaller pipe and then fix the smaller pipe into this aperture. Crude, but it is a solution.
This would however create problems in the pipeline because as well as simply moving fluids from A to B, a properly designed pipeline also has to move liquids efficiently. Most pipelines carry fluids which are being pumped. A step connection as described above introduces a restriction in the pipeline which will require increased pumping power to overcome it.
Also a step in a pipeline will act as a dam allowing any impurities to collect and build up. Over time this can lead to a restriction and blockage in the pipeline or even worse a slug of impurities could break off and travel down the line causing problems to fittings further downstream.
The answer to this problem is to fit a special reducing piece at any changes in pipe size.
At Chemipetro we manufacture a range of pipe fittings and flanges, including concentric and eccentric reducers in different materials including duplex and super duplex stainless steels so that you will always have the correct solution
Tags: Duplex, Flanges, Pipe Fittings, Super Duplex
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September 12th, 2010
Heat exchangers are used to transfer heating or cooling from one medium to another and are widely used in the petrochemical industry. They are simple in concept, but in practice can be quite complex. An example of a heat exchanger that most will be familiar with is a car radiator where the hot water flowing though one section is cooled by air passing in another direction.
In principle though, they fall into two categories; counter flow and parallel flow.
In parallel flow systems, the two fluids enter the exchanger at the same end and run through the unit side by side with heat transferring from the hotter fluid to the cooler one. In these systems, unless the liquids are drawn off earlier, the result will be they both end up at the same temperature which is roughly mid way between the starting temperatures of the two liquids.
However, if it is required to raise the temperature of one fluid to near the starting temperature of the other fluid then it is necessary to use a counter flow system. Here the fluids enter the pipe fittings at opposite ends and the temperatures are raised to near the temperatures of the heating fluid at the inlet.
These systems are commonplace but require specialist materials such as duplex and super duplex stainless steels as the inside of a heat exchanger can be a harsh environment. At Chemipetro we not only manufacture a wide range of pipe fittings and flanges that can be used to connect heat exchangers, we also manufacture the specialist pipe fittings used to make them.
Tags: Duplex, Flanges, Pipe Fittings, Super Duplex
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September 9th, 2010
A lot of products that are engineered for the petrochemical industry have much wider applications and uses. Pipe flanges and pipe fittings, for example, are not just used in pipelines for petroleum or chemical products, but can also be used for other more mundane applications such as pipelines for pumping water. It is not the type of fittings that are unique but the type of materials they are made from.
Water (unless it is sea water) is a far less corrosive medium than a lot of chemicals that are transported. Therefore for most simple applications it is possible to use cast iron or even plastic pipelines. However more corrosive elements as used in the petrochemical industry require a tougher material, and this is where the specialist stainless steels such as duplex and super duplex come into their own.
However, there are applications where even water can require a stronger material, and that is where high temperatures and pressures come into play as may be experience in boilers and heat exchangers. At Chemipetro we manufacture a special range of tubes for such applications.
Although boilers are used in heating systems heat exchangers have a much wider application. Basically, they are used where it is required to alter the temperature of one medium by transferring heating or cooling from a second medium. The two liquids (like oil and water) must never mix and are kept segregated by running in different pipelines. This process is used a lot in the chemical and food processing industry when it is necessary to heat up a medium during a manufacturing process or to chill another.
Tags: Duplex, Pipe Fittings, Pipe Flanges, Super Duplex
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September 6th, 2010
As well as specialist stainless steels such as duplex and super duplex, we at Chemipetro manufacture pipes, flanges and pipe fittings in other specialist metals. However, none of these metals are as recognisable by name as Titanium.
This is commonly known as ‘the space age’ metal and for good reason. Its unique properties have meant that it is has been used extensively in aeronautical and military applications.
Despite its relatively recent application however it has been around for quite a while. Titanium as an element is present in all living things as well as soil and rocks. However it was not identified until 1791 when amateur geologist William Gregor noted it in some sand samples. Four year later a German chemist, Martin Heinrich Klaproth also identified the mineral and named it after the Titans in Greek mythology.
However, it was over a hundred years before a usable metal sample could be produced and not until 1932 that the first commercial samples were made outside the laboratory.
Because of difficulties machining it, it was not until the 1950’s that Titanium first became widely used when the Soviet Union used it in submarines. However its important properties of strength and lightness were quickly recognised such that the Americans declared it a strategic metal.
Titanium is as strong as steel but 45% lighter. It is also very resistant to corrosion being able to withstand acid and chlorine attack. This makes it particularly useful for the petrochemical industry.
Therefore if you have a particularly aggressive environment to cope with that also requires strength in the fittings Titanium could be your answer.
Tags: Duplex, Flanges, Pipe Fittings, Super Duplex
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September 3rd, 2010
We at Chemipetro produce a wide range of pipes, flanges and pipe fittings in a range of materials such as duplex and super duplex stainless steels. We can also manufacture parts in specialist materials such as 6% Moly super austenitic stainless steels, or if you have a specialist application which may require something a little different to solve the problem, we can help to find the answer.
But what special qualities do these types of stainless steels have and why and where would you want to utilise them?
Molybdenum minerals have been on the market for a long time. Its name is derived from the ancient Greek word Molybdos meaning lead, with which its ores were confused for a long time. It was not until 1778 that a Swedish Chemist, Carl Wilhelm Scheele finally identified the mineral.
It has some unique properties in that it has the 6th highest melting point of any element and it readily forms hard stable carbides. When used as a component in stainless steels it produces a metal alloy which is very stable at high temperatures and is resistant to corrosive elements which would degrade other types of steel.
Another useful quality of this type of steel is its good weldability and resistance to hydrogen induce cold cracking and spot weld peeling. Other types of steels are not so easily welded and require the use of specialist welding techniques.
For this reason, it is particularly useful in applications such as equipment exposed to sea water, chemical processing and handling of materials that have high halide levels.
Tags: Flanges, Pipe Fittings, stainless steels, Super Duplex
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