Pig the flowmeter

Products overview:

ZW - ANB seriesPig the flowmeter(also called flute velocity-equalizing tube flowmeter) is based on the pitot tube principle of speed developed a new type of differential pressure flow detecting element, its output for the differential signal, and measuring the differential pressure instruments, can accurately measure the circular pipe, rectangular pipe in a variety of liquids, gases and steam (superheated steam and saturated steam flow, and for its high precision, small pressure loss, the advantages of convenient installation gradually replace orifice and other detecting element, in the power industry (including nuclear industry), chemical industry, oil and metal smelting industries widely used.

Second, the working principle:

ZW series - ANB pig the average flow velocity of flow meter is through the pipeline and pipe flow of product to determine the effective cross-sectional area.When the fluid flows through the sensor, a high pressure generated in the front of its distribution area, hydrostatic pressure slightly higher than the area of high pressure pipe.According to the principle of Bernoulli equation, to speed up the speed when the fluid flows through the probe, the probe at the back of the produce a low pressure area, the pressure is slightly lower than area of low pressure pipe of the static pressure.Fluid from the probe through the vacuum on the probe at the back of the part, and appear on both sides of the probe vortex.Average flow cross section shape of probe, the condition of surface roughness and low pressure hole location is the key to probe performance factors.Low voltage signal is stable and accurate, is crucial to average probe of precision and performance.Pig, average flow probe can be detected accurately by the fluid produced by the average speed of the average differential pressure.Pig, average flow probe in high and low pressure area according to certain criteria to take more pressure hole configuration, make it possible to accurately measure the average velocity.

Applications:

ZW series - ANB pig output for the differential signal, the flowmeter and measurement of differential pressure instruments and meters, can be accurately measured, pipe, rectangular pipe in a variety of liquids, gases and steam (superheated steam and saturated steam).The size of the pipeline under test range from 20 mm - 3000 mm.In the power industry (including nuclear industry) chemical industry, petroleum chemical and metal smelting industry departments such as the bank of China to the use of success, it is suitable for:

1, the gas and liquid transportation.

2, energy research, steam boiler heat rate, efficiency of pump, the gas compressor efficiency and fuel consumption.

3, process control, input and output, ratio and balance;Cooling water or air, steam heating.

4, material of chemical industry.

Four, the main features:

1, the unique internal structure of quadratic mean, provides the high precision reading (+ 1%) and high repeatability (plus or minus 0.1%).

2, the outer shock tube USES a single piece of material processing and welding, and welded together by twin hull structure similar products than those with natural zui, high strength and easy to use high temperature resistant, corrosion resistant material.

3, the hexagonal honeycomb structure stable, is produced by the unique shape of the distribution of a beam to ensure the stability of the low voltage signal, the differential pressure is higher than similar products, improve the range ratio.

4, suitable for square or rectangular pipe.

5, when dirt medium for similar products in the measurement of inevitable congestion, there are online can be pulled up or provide manual and automatic purging methods and devices, not achieve production maintenance.

6, velocity-equalizing tube + 3 + + transmitter temperature pressure compensation valve group, component integration structure, easy to use.

7, no flow coefficient, the long-term stability.

8, provide intuitive resonance check, ensure the long-term stable operation.

9, small pressure loss of low energy consumption, energy saving effect is remarkable.

10, installation convenient save artificial, low price quick delivery (1 week).

Five, the technical parameters:

1, specifications: (- DN5000 (mm);Insert: DN500 - DN5000 (mm);

2, the measurement accuracy: + / - 6.0%;Repeatability: + / - 0.1%;

3, scope: volume flow: 10:1;Mass flow rate: 8;

4, work stress: velocity-equalizing tube without functional: 20 mpa or less;

Velocity-equalizing tube can be put forward: 10 mpa or less;

5, fluid temperature: 450 ℃ or less;

6, medium viscosity: 30 or less cp (crude oil);

7, material:

A, velocity-equalizing tube, three groups: a variety of grades of stainless steel (optional);

B, main pipe, flange, stainless steel or carbon steel (optional).A typical to 10:1 (the differential value of 100:1);

Six, the pig and the advantages of the flow sensor (compared with the orifice) :

1, high accuracy, good stability

Pig, the accuracy of the flow sensor is plus or minus 1%, stability is plus or minus 0.1%, it can maintain a long-term very stable output differential pressure signal, to ensure that the output differential pressure signal and pipeline flow mapping relationship.This is because in the process of use wear, corrosion and adhesion of oil dirt on the meter coefficient of impact is not big, but these factors make the orifice discharge coefficient increases, and will rise to more than 20%, the error produced by this will reach more than 20%.From which we can see that the accuracy is stable for a long time.

2, reasonable design, easy installation, economy

Light weight, easy installation and disassembly, without lifting tool, the series of products are can be measured, the pipe does not block the flow under the condition of no parking to install or remove, because of light weight, easy installation and disassembly, so this can save you considerable cost of installation.For example: in the 200 mm diameter pipe installed on the flowmeter, only a 150 mm weld, and orifice has 2, a total of 1200 mm long long weld.In terms of working hours, install only need 1.5 hours, while installing an orifice plate to 12 hours.

3, is advantageous to the piping layout

Not only suitable for round pipe, also apply to the rectangular pipe and any depth of pipeline buried under the ground.The length of the straight pipe upstream and downstream demａnd was much lower than the orifice plate, when the installation is behind the elbow distance 2 times the pipe diameter, still can get a stable, high accuracy, the unique advantages, to pipe especially large diameter pipeline layout design brings a lot of flexibility, save the cost.

4, small pressure loss, less energy consumption

* * the pressure loss is power loss, pressure loss of just 2-15% of differential pressure, and general orifice * loss is to account for 40 to 80% of the differential pressure, can be seen from the chart below the pressure loss of the * pressure loss is much smaller than orifice plate, with the increase of pipe diameter, pressure loss of the * negligible.For example: use on the pipe with a diameter of 1000 mm, the energy loss in the year only a few hundred dollars, when using orifice plate, energy losses as high as 20000 yuan a year, it is for today to try to save energy have opinions.

Pig, the blockage of flow sensor design.

1, pig, the unique design of probe thoroughly get rid of the past several average probe easily blocked, the characteristics of accuracy is not high, make a source of measurement accuracy, repeatability and reliability to a new height.

2, just boot, the fluid in the pipeline under the action of static pressure, into the pipe bending, quickly formed a pressure balance state.When pressure balance formation fluid in high pressure pipe inlet, detour, no longer into the bend.

3, pig, high flow sensor, low take pressure hole held in nature.

4, in general, dust, sａnd and particles under the action of the vortex street force, concentrated in the very back of the probe.This is why the autumn leaves are always in the leeward behind the house.Probe flowmeter probe held in unique design, coupled with the nature of gravity whereabouts, prevents the particles into, this design essentially prevent the congestion and can create a very stable low voltage signal.

5, continuous work of fundamentally put an end to the possibility of the wall, but in the following cases, still should pay attention to prevent:

A. when pressure pipe leaking, probe high pressure balance to destruction of impurities in the diameter of the smaller particles are likely to enter the hole.

B. when pipe production at, because of the brown movement of molecules, small particles of impurities may enter the hole.

C. system key, frequently at the instant of the high formation, small particles of impurities may enter the hole, accumulate over a long period, it is possible to probe the jam.

D. medium contains a large number of biological species, or containing fibrous material, may also cause the probe blockage.

Main components:

1, according to pipe diameter custom of pig, installed on the pipe with flange, made of stainless steel refined but become, according to the users with various parameters, the high precision wind tunnel laboratory simulation, will the characteristic curve and database, used for calculation.

2 is to display the measured results, flow totalizer.especially secondary instrument.Through wires connected to each transmitter and thermometer, the motherboard is equipped with advanced CPU and the application software, can use the display window and switch button to setup, calibration and the parameters display.

3, differential pressure transmitter will will convert the differential pressure signal of 4-20 madc analog current signal.

4, pressure transmitter in the gas flow measurement with pressure compensation.

5 in gas flow measurement, temperature transmitter temperature compensation.

6, dc power supply for pressure transmitter, differential pressure transmitter power and thermal resistance thermometer.

Nine, form a complete set of scheme selection:

1, is according to the measured medium, and the user use the pipe inner diameter, working temperature, working pressure and flow design and production.

2, ZW - 3051/1151 dp series differential pressure transmitter or other types of differential pressure transmitter.

3, ZW - 308 series pressure transmitter, or other type of pressure transmitter.

4, temperature transmitter, or other type of temperature transmitter.

5, ZW - XMJA series or other types of flow totalizer.especially flow integrating instrument.

6, of this intelligent velocity-equalizing tube flowmeter, pressure compensation can take temperature, and can show the instantaneous flow and cumulative flow medium medium temperature, the pipe, the pipe pressure and differential pressure equivalent, equipped with communication interface and 4 ~ 20 ma output.

Ten, device:

1, velocity-equalizing tube flow sensor 1;

1 2, velocity-equalizing tube flow sensor operating instructions;

3, 1 certificate;

4, form a complete set of transmitter instrument and manual and certificate of approval (which can be ordered by the users themselves).

12, product maintenance instructions:

Pig the flow sensor should be regular cleaning when process piping overhaul, there are a number of ways for cleaning, such as air blow test tube accumulated filth;Scrub with kerosene and soft silk net, make each hole to maintain patency.May produce the cause of the failure and remove methods: serial number of failure causes clear way.

1, differential pressure signal output: high and low pressure valve is not open, open the high and low pressure valve.

2, high and low pressure balance valves did not tighten, tighten balance valve.

3, differential pressure signal output is too small, pressure system has a leak phenomenon;Seriously looking for, eliminate the leakage.

4, improper secondary table range selection: uninteresting facts limit pressure transmitter.

5, differential pressure signal output is too large, secondary table range matching is undeserved, augmenting the upper limit, differential pressure transmitter back-pressure aperture jams, cleaning velocity-equalizing tube, eliminate congestion.

13, use requirements:

1, the current body shall be full of pipe flow and stability.

2, the fluid being measured should be single phase, the phase constant, the composition of complex fluid must be similar to a single component of fluid can be used.

3, the current body under actual conditions of ReD should be greater than 3 x 104.

4, should guarantee the sensor before and after the straight pipe length requirements.

5, pipe diameter greater than 100 ㎜ as well.

6, 2 d in front of the sensor on the surface of the pipe, should be clean and smooth.

14, operation and maintenance:

The preparing work before put into operation:

1, sensors installed correctly:

Complete sensors installed in the line, must carefully check before put into operation, require welding is firm, in the right direction, not leak, strictly proper insertion depth, etc.

2, instrument calibration:

Sensor matching instrument differential pressure transmitter and intelligent flow integrating instrument (there could be pressure transmitter and temperature transmitter), etc.Must be after inspection and calibration, can be put into use.The instrument measuring range to conform to the requirements of the sensors and the measured medium.Such as air flow to be tested Qmax = 5000 m3 / h, the calculation to calculate differential zui big value of sensor

Delta Pmax = 0.6 Kpa, the measuring range of differential pressure transmitter should be set-up of 0 ~ 0.6 Kpa, the corresponding output 4 ~ 20 madc current signal.For universal, flow totalizer.especially should according to the real-time flow range, differential pressure range, medium density, temperature, pressure, flow operation requirements, etc., prior programming configuration, input totalizer.especially can correct operation and make sure totalizer.especially display traffic.

3, instrument wiring correct:

Sensor and differential pressure transmitter, flow integrating instrument of measuring system, such as supporting the power cord, signal output to the input line between instrument, control and alarm, etc., in various instrument wiring board (also known as terminal board) are clearly marked, is must confirm and don't choose to use, before the operation of the instrument connection to check again and again.In order to do the preparing work before put into operation, in addition to read the instruction for use, you should also read the differential pressure transmitter operation instruction handbook ", "operation instruction handbook" intelligent flow totalizer.especially etc, comply with the instruction manual for the guidance of work.

The flow operation of work:

1, the measurement system is closed:

Operation of preparatory work has been completed, the medium to be measured with flow process piping, sensor measuring system is temporarily closed, then should make three balancing valve is fully open valve group, high pressure valve Pl P2 and low pressure valve closed.Meter is in a state of power supply, preheating about 15 minutes.

2, open measurement systems:

Instrument after preheating, open measurement system.Open the Pl on three valve group and P2 valves, balance valve is still in the open.At this time, the differential pressure transmitter has filling the measured medium (gas or liquid), open the drain valve on the transmitter, quickly closed after discharge dirty liquid or gas.Then close three the balance valve on the valve group, transmitter that is entered into a state of differential pressure measurement.Output and the corresponding signal current differential delta P I delta P from the signal current value (m A) to calculate the pressure delta P values (KP) A.Also flow totalizer.especially into work state, show the measured medium flow.

If the above work all goes well, the flow meter works well, commissioning work is complete, delivery production use.

15 and selection considerations:

1, the pig and the mechanical size is according to the size of the installation of pipeline tailored, its measuring range is provided according to the craft flow calculation and calibration data.Selection, must give manufacturers to provide the correct flow data and pipe size, pipe size including outside diameter and wall thickness.Flow meter must be installed according to the standard, to ensure that the error of the measuring system in the permitted range.

2, test the front of the sensor pipe must ensure that there are 7 ~ 9 d d straight pipe length (the various manufacturers have different information, data from a 3 d and 30 d whole), to make the big pipe the flow velocity of liquid, gas (vapor) axis symmetrical distributed in as far as possible.Only in this way, the flow rate of the measured points can be calculated through the whole cross section of flow, otherwise the big pipe of liquid, gas (vapor) velocity distribution will be very complicated, fluctuations in discharge coefficient K will be very big, can guarantee the accuracy of the measurement.But in the actual process design can't guarantee a long straight pipe.The author thinks that if determined to choose some kind of, can consult with suppliers under the precondition of guarantee system of repeatability, try to shorten the straight pipe, the relevant information, as long as the ratio of the diameter and process pipe diameter measurement is less than 1/10, the front line of straight pipe length to be 3 d to 4 d.

3, lever measurement sensor, total pressure hole must be positive to flow, deviation is not more than 7 °.Detection rod should be inserted to the bottom along the pipe diameter, and the vertical pipeline detection bar can be installed in horizontal pipe along the pipeline circumferential 360 ° in any position.High and low lead pressure tube should be in the same plane;For horizontal pipe, measuring lateral tilt down when installation.Flow meter can be measured accurately and the length of its service life has direct relationship with whether or not installed correctly, once the flow meter installed, has affected the accuracy of flowmeter system error will always accompany, it is difficult to remove from the software.You may refer to the correct installation of differential pressure type flowmeter installation specification, go here.

4, test rod through joint fixed on the pipeline, tighten the joint, after testing stem not loosening and leakage.Pipeline vibration and fluid impact can make detection rod fixed head mobility, detecting rod fracture damage, affect the accurate measurement and cause economic losses.

16, selection of coding:

17, design selection and order notes:

1, the name of the measured medium;

2, the biggest, commonly used, flow range (m3 / h);

3, work pressure (Mpa), temperature (℃), the maximum pressure (Mpa), upper and lower temperature (℃);

4, medium density, viscosity,

5, pipe material, inner diameter, outside diameter;

6, the pipe laying and local resistance.

7, you need to display instrument of the measurement and control of form a complete set, please refer to the corresponding specifications, choose the right model or the information provided by our company technical personnel according to your designs for you selection.

8, if you have special want to, please contact our sales department.

After-sales service commitment:

1, from the date of signing of the contract, I in the way provided for products of the company offers free maintenance and maintenance service, commitment to lifelong maintenance service;

2, jiangsu wei measurement and control instrument co., LTD. Sales manager will be in regular contact with customers, understａnd the usage of products, and solve the problems of the customers to use in the process of produce, free of charge to provide technical support;

3 the man-made damage is found, the warranty period, our company is responsible for the maintenance, and the resulting maintenance fee;

4, product quality problems or are not satisfied with product, the user can choose unconditional return, wei tt&c don't charge any fees, appear quality problem, bear the freight back and forth.