If you need to order, please contact our company. As the fluid approaches the orifice the pressure increases slightly and then drops suddenly as the orifice is passed. The decrease in pressure as the fluid passes thru the orifice, is a result of the increased velocity of the gas passing thru the reduced area of the orifice. When the velocity decreases as the fluid leaves the orifice the pressure increases, and tends to return to its original level.
The differential pressure is proportional to the square of the velocity, it thus follows that if all other factors remain constant, then the differential is proportional to the square of the rate of flow. At least keep the equal diameter straight pipe section of the first 10DN and the rear 5DN to improve the measurement accuracy.
The regulating valve should be in the pipeline after 5DN downstream. Usually, a pipe with an inner diameter of mm is used within 45 meters.
If the throttle is installed on the vertical pipeline, the short pipes should be separated by a certain distance in the vertical direction. The two pressure-taking pipelines should be as close as possible to each other and far away from the heat source or vibration source. When measuring the water vapor flow, they should be wrapped together with insulation materials.
When measuring the dirt flow, an isolator or settler should be attached. When the measured fluid is a gas, all the pressure in the impulse pipeline including the pressure chamber of the differential pressure gauge is in the gas phase. When the measured fluid is a liquid, all the pressure pipes are in liquid phase, and there must be no bubbles.
For this reason, a drain valve should be installed at the lowest point of the impulse pressure pipeline or an exhaust valve should be installed at the highest point. Pay special attention to the new installation or maintenance of the differential pressure transmitter. The installation direction of the orifice flowmeter is not specified. But there is a rule that the flow direction of the medium cannot be reversed.
The orifice flowmeter can be installed according to the flow direction of the arrow of the flowmeter. Globe Valve. Check Valve. Ball Valve. Plug Valve. Butterfly Valve. Diaphragm Valve. Steam Trap. Expansion Joint. Sight Glass. Flame Arrestor. Flange Guard. Access Fitting. Pig Signaller. Insulating Gasket Kit. Isolation Joint. Pipe Penetration Seal. Breather Valve. Pipe Dimensions. Fitting Dimensions. Flange Dimensions. Valve Dimensions. Bolt Dimensions.
Gasket Dimensions. Process Plant Layout. Layout Offshore Platforms. Safety in Design. Bolt Design. Gasket Design. Flange Design. Pipeline Design. Pressure Temperature Ratings. Piping Design General. Stress and Supports. Stress Theory. Supports General. Support Spans. Spring Support. GRE Pipe Supports. Structural Sections. Hot Tapping. Unit Conversion. Pipe Wall Thickness. Pipe Support Span. Weight Calculations. Piping Stress Analysis.
Construction Related. Flange Calculations. Recent Questions. Flow up may be the better direction, but horizontal flow appears to be more common. Orifice Plates should never be installed in a down flow application. Liquid separation is possible yielding poor readings.
As always, there are cases when a down flow can be made to work by designing the line to maintain a flooded condition, but generally this is a last resort and not good design practice. Orifice Plates are installed between special flanges referred to as Orifice Flanges Weld Neck Style Flange with a tapped hole and are Class or greater flanges.
These flanges have tapped holes through the flange body to the pipe center and are on either side of the orifice plate for differential pressure measurement. Class flanges are not thick enough for the tapped hole. As such Class flanges are used in Class and Class systems. Because of the long straight run requirement before and after the meter, meter runs can sometimes take up a lot of space.
Hence, they are best placed along wall lines where they will not affect foot traffic in the plant. In the case of having a descending fluid, the impulse piping must be configured as shown below. In general, the circulating fluids through the process pipes should not be carried through the instrument connection lines to control rooms , interconnection rooms, local panels or any room that may be closed or partially closed.
As a general rule the instruments should be mounted as close as possible to the impulse intakes and in areas with high ventilation. The shorter the lengths of the lines, the less possibility of leakage, plugging and higher speed in the response of the transmitter to variations in the differential pressure.
The possibilities of error decrease with short lines. On the other hand, long lines require greater support, take up more space, require more materials and have a higher risk of leakage. However, the good location and accessibility of the instruments in accessible ground or platforms is one of the fundamental factors for the execution of a good maintenance.
The savings in stairs, scaffolding, hours of execution of the works and the increase of the safety, compensate in a short time the extra initial cost of this type of assembly.
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Orifice Plate Installation Guidelines. What is an Orifice Plate? Location of the connections in the pipe or flanges 4. Horizontal Installation Guidelines 4.
Vertical Installation Guidelines Length of connection lines to the process References. Download your free PDF file about how to install an orifice plate! Rating: 4. Orifice Plate Installation Detail. How does Orifice Plate Work?
General Installation requirements: The orifice meter must be installed between two mating flanges in the pipe. For liquid metering, the pipe should run full at the measuring section. The diameter of the tube must be circular over the measured length. The internal surface of the measuring pipe must be clean and free of scale, pitting and deposits or any other possible source of turbulence.
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