What is the difference between a single flange and a double flange liquid level transmitter?
In the liquid level measurement, the selection of the transmitter is divided into single and double flanges. What are the differences between the two? Below, Yikong Jun will take everyone to find out!
Single flange concept
Double flange concept
Double flange means that the positive and negative pressure sides of the transmitter are flange structure, which can be directly connected to the container and pipeline to be measured. The advantage is that the installation is easy, the calibration is convenient, and the range migration is not required. The disadvantage is that the measurement accuracy is not high. Because the flange and the transmitter are connected by elastic hose, the inside should be filled with silicone oil, so there is a certain deviation in the transmission of the medium pressure change. The external temperature change is more or less. Influence, so there is a certain error in the measurement.
Single flange and double flange level transmitter application
Where are the single flange and double flange level transmitters applied?
In fact, it is very simple. The single-flange liquid level transmitter uses the measurement of the open tank. Sometimes some meter workers also choose the economical input test level transmitter. Conversely, the double flange level transmitter is suitable for level measurement of sealed tanks.
Liquid level transmitter measurement principle
The liquid level transmitter is a simple and reliable measuring instrument for measuring the liquid level in the tank. The principle of P=ρgh is used to measure the differential pressure to measure the liquid level. The level of the liquid level is proportional to the differential pressure measured by the liquid level transmitter. The process connection of the liquid level transmitter is usually a diaphragm flange type, and the diaphragm is filled with silicone oil as a pressure transmission medium. The liquid tank usually has an open tank and a pressure tank. The upper part of the open tank is open to the atmosphere. The liquid level transmitter for measuring the liquid level of the open tank only needs to connect the process flange with the high pressure end and the atmosphere to the low pressure side. The pressure tank needs to be connected to the diaphragm flange type on the high and low pressure sides of the liquid level transmitter to measure the pressure difference between the high and low pressure side.
Flange specifications for installing level transmitters
Usually the end user and the design unit will require the liquid level transmitter package to provide a matching flange to prevent the mismatch between the mating flange and the level transmitter process flange on the tank during field installation. The mating flange specifications can be selected based on the following options:
The flange standard, flange size, flange pressure level and flange form are determined against the selection samples of different level transmitter manufacturers.
Flange standard:
There are usually three standards for level transmitter mating flanges:
The DIN standard, the ANSI standard and the Japanese standard are used in the domestic DIN standard and ANSI standard.
Flange size:
It is the same as the standard of the liquid level transmitter. For details, please refer to the sample selection of the liquid level transmitter manufacturer. The level of the level transmitter flange is mainly 2''; 3'' and 4'', of which 3'' is most common.
Flange pressure level:
The Japanese standard is JIS 10K and JIS 20K;
The ANSI standards are ANSI 150, ANSI 300, and ANSI 600;
The DIN standard is DIN PN10/16; DIN PN25/40. (Note: For 3'' flanges PN10 and PN16 are the same size; PN25 and PN40 are the same size)
Flange form:
Depending on the pressure level and customer requirements, for flat pressures less than 40 barg, plate flat welding is usually preferred; for pressures greater than 40 barg, neck butt welding is usually preferred;
Flange material:
Common flange materials are carbon steel, SUS304 and SUS316. The mating flange of the same material should usually be selected according to the material of the tank.
Corresponding to domestic flange standards are:
GB/T 9115-2010: welded steel pipe flanges;
GB/T 9116-2010: welded steel pipe flange with neck;
GB/T 9117-2010: steel pipe flange with neck socket welding;
GB/T 9119-2010: Plate type flat welded steel pipe flange.
Read more:
Comparative Analysis of Three Typical Liquid Level Measuring Devices, such as Differential Pressure Transmitter
In the liquid level measurement, the selection of the transmitter is divided into single and double flanges. What are the differences between the two? Below, Yikong Jun will take everyone to find out!
Single flange concept
The single flange means that the positive pressure side of the transmitter is a flange structure, which is directly connected to the interface of the measuring medium, and the negative pressure side is connected with the measuring medium by the pressure guiding tube. The advantage is that the measurement accuracy is high, and the measurement technical index of the transmitter can be achieved. The disadvantage is that the negative pressure pipeline must be absolutely sealed, and the transmitter needs to be subjected to the range migration, and the error migration of the medium liquid in the negative pressure pipeline should be carried out during the verification. Drop it.
Double flange concept
Double flange means that the positive and negative pressure sides of the transmitter are flange structure, which can be directly connected to the container and pipeline to be measured. The advantage is that the installation is easy, the calibration is convenient, and the range migration is not required. The disadvantage is that the measurement accuracy is not high. Because the flange and the transmitter are connected by elastic hose, the inside should be filled with silicone oil, so there is a certain deviation in the transmission of the medium pressure change. The external temperature change is more or less. Influence, so there is a certain error in the measurement.
Single flange and double flange level transmitter application
Where are the single flange and double flange level transmitters applied?
In fact, it is very simple. The single-flange liquid level transmitter uses the measurement of the open tank. Sometimes some meter workers also choose the economical input test level transmitter. Conversely, the double flange level transmitter is suitable for level measurement of sealed tanks.
Liquid level transmitter measurement principle
The liquid level transmitter is a simple and reliable measuring instrument for measuring the liquid level in the tank. The principle of P=ρgh is used to measure the differential pressure to measure the liquid level. The level of the liquid level is proportional to the differential pressure measured by the liquid level transmitter. The process connection of the liquid level transmitter is usually a diaphragm flange type, and the diaphragm is filled with silicone oil as a pressure transmission medium. The liquid tank usually has an open tank and a pressure tank. The upper part of the open tank is open to the atmosphere. The liquid level transmitter for measuring the liquid level of the open tank only needs to connect the process flange with the high pressure end and the atmosphere to the low pressure side. The pressure tank needs to be connected to the diaphragm flange type on the high and low pressure sides of the liquid level transmitter to measure the pressure difference between the high and low pressure side.
Flange specifications for installing level transmitters
Usually the end user and the design unit will require the liquid level transmitter package to provide a matching flange to prevent the mismatch between the mating flange and the level transmitter process flange on the tank during field installation. The mating flange specifications can be selected based on the following options:
The flange standard, flange size, flange pressure level and flange form are determined against the selection samples of different level transmitter manufacturers.
Flange standard:
There are usually three standards for level transmitter mating flanges:
The DIN standard, the ANSI standard and the Japanese standard are used in the domestic DIN standard and ANSI standard.
Flange size:
It is the same as the standard of the liquid level transmitter. For details, please refer to the sample selection of the liquid level transmitter manufacturer. The level of the level transmitter flange is mainly 2''; 3'' and 4'', of which 3'' is most common.
Flange pressure level:
The Japanese standard is JIS 10K and JIS 20K;
The ANSI standards are ANSI 150, ANSI 300, and ANSI 600;
The DIN standard is DIN PN10/16; DIN PN25/40. (Note: For 3'' flanges PN10 and PN16 are the same size; PN25 and PN40 are the same size)
Flange form:
Depending on the pressure level and customer requirements, for flat pressures less than 40 barg, plate flat welding is usually preferred; for pressures greater than 40 barg, neck butt welding is usually preferred;
Flange material:
Common flange materials are carbon steel, SUS304 and SUS316. The mating flange of the same material should usually be selected according to the material of the tank.
Corresponding to domestic flange standards are:
GB/T 9115-2010: welded steel pipe flanges;
GB/T 9116-2010: welded steel pipe flange with neck;
GB/T 9117-2010: steel pipe flange with neck socket welding;
GB/T 9119-2010: Plate type flat welded steel pipe flange.
Read more:
Comparative Analysis of Three Typical Liquid Level Measuring Devices, such as Differential Pressure Transmitter
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