January 27th, 2011
As well as a wide range of pipe fittings and flanges manufactured in different sizes and materials to meet any need such as duplex steel, we at Chemipetro also manufacture much more everyday items under our fasteners section such as nut bolts and washers.
When compared to more complex pipe fittings such as swivel flanges or induction bends these may seem to be mundane components but in fact they are in their own way just as complex a piece of engineering.
Although the screw thread has been around for several thousand years since invented by Archimedes, it is only in the last one hundred and fifty years that standard thread standards have been produced. Before this time threads were made individually, each manufacturer producing a unique product. With the growth of the engineering industry it quickly became necessary for standard thread types to be produced. Even so there were several standards in use such as British Stand Fine Thread (BSF) and British Standard Witworth (BSW). It was not until the 1960s and 1970s that metric standards became the normal standard.
Even so there are still a number of standards that we manufacture to depending on the use the fastening is to be used for. These relate more to the type of bolt head used such as hex head or twelve point ferry head. Even simple things such as washers are manufactured to different standards depending on whether you want a plane washer or a spring washer. That’s before we even get started on the material it is to be made from. And you thought a bolt was just a simple thing.
Tags: Flanges, Pipe Fittings, Pipe Flanges, pipes
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December 3rd, 2010
Under the heading ‘Design of a Pipeline’, the Pipelines Safety Regulations 1996 state three guiding parameters in the design of any pipeline. These include that firstly the pipe must be able to withstand any forces that arise from its operation, secondly it can withstand the fluids it is actually transporting and thirdly it can also withstand any external forces or chemical processes to which it may be subject.
These seem pretty fundamental design requirements, but it should be considered that the regulations were written because at some time in the past someone did not design a pipeline in this manner and it failed in service.
The first requirement takes into consideration the working pressures under which a pipeline will operate. This will determine the types of pipe fittings and flanges that will be employed. Some flanges, such as swivel flanges, may be easier to install but may not be rated to cope with the pressure. This requirement also works in the designers favour as the pipeline does not all have to be installed to meet the highest pressure but where there is a pressure reduction in the line the pipe fittings used can also be of a simpler type.
An example of this is the fittings required to meet the high pressures at a well head have to be of the highest standard but further along the pipeline where the pressure is reduced, different types of fittings can be installed.
At Chemipetro we manufacture a wide range of flanges and pipe fittings to all standards so we can be sure to find the one you need.
Tags: Flanges, Pipe Fittings, pipes, swivel flanges
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November 9th, 2010
At some stage in any installation it is necessary to install a meter or sensor point to measure the flow rate or pressure of the liquid in the pipeline. In order to achieve this it is necessary to introduce an orifice plate into the pipeline.
An orifice plate is the same size as the pipeline with a hole in the middle which is slightly smaller than the pipe. This introduces a restriction in the flow. As the flow is restricted, the velocity of the fluid increases. Once the fluid has passed the orifice plate and can expand it slows down again. Bernoulli’s principle states that as the velocity of a fluid increases there is a reduction in the pressure it exerts on its surroundings so that there is a direct relationship between the pressure measured and the velocity of the fluid. Therefore by measuring the pressure of the fluid it is possible to determine its velocity and if the velocity of the fluid is known it is a simple matter to determine the flow rate for a given size pipe.
So by measuring the difference in pressure either side of the orifice plate in the area of the normal and increased velocities and by applying these figures to Bernoulli’s equation it is possible to determine the flow in any given pipe.
At Chemipetro we manufacture orifice flanges as one of our range of flanges and pipe fittings. The flanges are specially designed to incorporate an orifice plate and have specially tapped holes in the ring so that pressure gauges can be installed.
Tags: Flanges, Pipe Fittings, Pipe Flanges, pipes
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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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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.
Tags: Pipe Fittings, pipe joints, pipes, pipework
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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
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