Integral Orifice Flowmeter

Integral Orifice Flowmeter medium flow through the pipeline methodological characteristics million Czech plant instrumentation There are several, but the most widely used, the most common is the differential pressure flowmeter. It gauge and differential pressure by throttling device or by a throttling device, together with a differential pressure transmitter together constitute the second table. A long history of use throttling device, have been standardized in the international and domestic. Throttling device is a component when the differential pressure measurement, people use it to generate the fluid pressure in the pipe. The use of lead pipes to transfer pressure generated by the front and rear differential throttling device to the differential pressure transmitter, and then entered into the secondary instrument, will show the instantaneous flow or accumulation of fluid in the pipe flow. Use adjustable flow meter can also be adjusted. Throttling device structure is simple, accurate measurement, reliable, maintenance, maintenance is very convenient. Uses LG / FB Standard ring chamber orifice, flange plate throttling device is no scale of flow measurement devices, which with pneumatic, electric or dual bellows differential pressure transmitter supporting the use of differential pressure transmitter. Pressure in the metallurgical, chemical, petroleum, power industrial systems continuously measure the medium temperature ≤400 ℃ of liquid, gas and steam flow through the orifice plate produced by the differential pressure transmitter signal into an output signal proportional, then There are secondary instrument or regulator, to be measured flow records, direction or regulation. Works throttling device is causing artificially throttle (Figure 1 below) in the medium circulation pipe. When the measured medium flow stream holidays means, resulting in a local contraction, stream concentration, the flow rate increases, the static pressure is reduced, so in the orifice upstream and downstream sides of generating a static pressure differential. This was the difference between the static pressure and the flow rate of a certain function, the greater the flow, generated by static pressure difference larger, so by measuring the differential pressure method, can be measured is the flow rate. Structure Structure throttling device shown in figure II, III: Structural features a donut take pressure standard orifice plate: the case of standard orifice plate. Due to achieve a donut to take pressure, improve the measurement accuracy, shorten the minimum required length of straight pipe installation can be widely used in various sectors. 2, fillet drilling alone take pressure standard orifice plate: the case of standard orifice plate. When the diameter of 400 mm or more, the use of this form. Pressure way to take pressure flange drilling alone, to take pressure equalizing ring round or square to take pressure equalizing ring. Shank-well format for holes or nonstandard round orifice and so on. 3, flange pressure standard orifice: the case of standard orifice plate. Whether it is the pipe diameter, and its upstream and downstream pressure tap centers are located on both sides of all kinds from the end face of each orifice 1:00 (25.5mm) at refining system widely used this form. 4, to take pressure away from the standard orifice diameter: the case of standard orifice plate. Pressure way to take pressure pipeline. Upstream pressure hole center is located at the front of the plate to double pipe diameter. End face of the inner diameter of the tube and a half where the center is located downstream of the hole to take pressure away from the orifice plate after. 5, small orifice: the case of non-standard plates. For measuring the measurement within 10 to 50 mm diameter fluid. 6, double plate: two standard orifice by a certain distance from each other in a straight pipe installed components. Depending on the direction of the stream, the front anti-called secondary orifice hole behind the plate called a master plate. Auxiliary plate section than m1 is greater than the primary orifice section than m. Two plates with a liquid wall constitutes a similar nozzle. It is used to measure the low Reynolds number flow or high viscosity fluids. 7, round orifice: the case of non-standard orifice plate, suitable for dirty, or analysis of the bubbles, or measuring fluid flow containing solid particles, the lower the measurement accuracy. 8, conical entrance orifice: the case of non-standard plates. Circular cone angle with the center line was 45 °, this conical entrance orifice can be applied to a very low Reynolds number of occasions, but not less than 25 mm pipe size. 9, other. Features 1) Standard hole Edition - has high accuracy, easy to install, using a wide range, and low cost. Widely used in flow measurement with a variety of media. 2) the standard nozzle - with a high temperature high pressure, impact resistance, long life, large measuring range and high measurement accuracy. Suitable for high temperature and high pressure steam power plant flow, thermal network path, large fluid flow velocity measurement. Has two forms: A: ISA1932 nozzle (standard nozzle) B: Long Neck nozzles. 3) classical Venturi tube Venturi nozzle - with a pressure loss, high accuracy, short length of straight pipe before, long life characteristics. 4) wing wind measuring device - a small pressure loss, a shorter front straight, measure stability characteristics. 5) Double Venturi tube - with a pressure loss is small, measuring stability, suitable for round or rectangular duct air flow measurement. Specifications: DN80-4000mm (or length × width). 6) Circular plates, round orifice, eccentric orifice - have clogging, short front and rear straight pipe characteristics. Suitable for blast furnace gas, coke oven containing powdered coal, etc., measuring impurities pay much gas and liquid. 7) dual circular nozzle orifice 1/4 - use a variety of low Reynolds number flow state, widely applied in a variety of low flow measurement of liquid flow rate, gas. 8) Annubar - with a pressure loss is small, easy installation features. Applicable circular, rectangular pipe flow measurement. 9) limiting orifice - have limiting buck characteristics. Applies to limit the flow or blood pressure. 10) single and double rooms to balance container - for level, drum level. Selection 1) Standard hole version * means flanged pipe and other materials, cutting pieces of stainless steel material. 2) an annular orifice, round orifice, eccentric orifice flange pipes, etc. * refers to the material, cutting pieces made of stainless steel. 3) single and double rooms to balance container * means flanged pipe and other materials, cutting pieces made of stainless steel. Technical Specification No. Name Model nominal diameter Dg (mm) Nominal pressure Pg (kg / c) Note 1 fillet ring room to take pressure standard orifice LGK-H-10 LGK-H-25 LGK-H-64 LGK-H-100 50-400 50-40050-400 50-400102564 1001, according to user needs the company can provide the following flange standards (1) Ministry of Chemical Industry Standard HG5010-5016-58 (2) Ministry of Machine standard JB78 ~ 82 59 (3) MEW Code Standard (4) according to user drawing processing. 2, the orifice plate material is generally stainless steel. 2 fillet individually drilled to take pressure standard orifice LGK-E-6 LGK-E-10 LGK-E-16 LGK-E-25 400-2000 400-2000 400-2000 400-2000 6 10 16 25 3 Flange Pressure standard orifice LGK-F-10 LGK-F-25 LGK-F-64 LGK-F-100 50-750 50-750 50-750 50-750 10 25 64 100 4 span to take pressure standard orifice LGK -J-6 LGK-J-25 LGK-J-64 LGK-J-100 50-2000 50-2000 50-1000 50-600 6 25 64 100 5 small orifice LGX-25 LGX-64 10-50 10 -50 25 64 6 round orifice LGQ-6 LGQ-16 50-2000 50-1600 6 16 complete supply of the Company, namely: plates, donut, flange and tighten bolts. Users can also be ordered separately or orifice plate donut, if you owned a flange, to be told I owned flange standards and sizes. When the attachment (a) In order to avoid the condenser temperature medium impact on the differential pressure gauge, measuring more than 70 ℃ temperature steam and water pressure leading pipeline need to install the condenser. A condenser, is the impulse tube measured vapor condensation, and positive and negative pressure impulse pipe condensate level has an equal height and kept constant. Condenser Specifications Model Working pressure Kg / c FL-64 FL-100 64 100 (b) of the isolator for high viscosity, corrosion, easy to precipitate the measured liquid solids and corrosive gases should be used isolators, so fluid to be measured not in direct contact with the differential pressure gauge or differential pressure transmitter, so as not to make the differential (or differential pressure transmitter) damage. Isolator Specifications Model Working pressure Kg / c Remarks FG-64A FG-100B specific gravity of less than 64,100 measured media isolation liquid FG-64A FG-100B 64 100 measured medium gravity greater than isolation solution (three) on a variety of settler measured gas pressure at the lowest point of the guide tube settler should be installed in order to collect and regular discharge pressure pipe in the dirt and water. Settler Specifications Model Working pressure Kg / c CJQ-64 CJQ-100 64 100 (d) of gas collector when measured fluid is a liquid, the pressure at the highest point of the guide tube gas collector should be installed in order to collect and regular Signal pipe discharge gas. When installing differential pressure gauge or differential pressure transmitter position above the main channel, it should set the gas collector. The basic set of requirements specification models working gas pressure Kg / c JQQ-64 JQQ-100 64 100 to install (a) Installation: 1, orifice should be checked before installation throttling device number and size of the pipe installation meets the requirements of the position. 2, the newly installed pipeline system must be installed in the pipe orifice line after washing and sweeping. 3, note that the orifice plate installation direction "+" sign should be toward the stream. 4, plate and pipe centerline center should coincide, concentricity error shall not exceed 0.015 (1 / β -1) values. 5, should be installed in a pipe orifice guarantee its end and the pipe axis vertical, vertical error should not exceed ± 1 °. 6, the clamping plate with the gasket (including the flange between the donut, donut orifice plate), after clamping the pipe wall may not broke. 7, the orifice must be installed at the tight, does not allow leakage exists. Therefore, the installation must be carried out before the pipeline pressure test. 8, guide pressure pipe should be vertical or inclined laying its inclination not less than 1:12. High viscosity fluids, but also increases its inclination. When the differential signal transmission distance of more than 3 meters, pressure pipe should be segmented guide tilt and the highest and lowest points each were installed gas gathering and settler. 9, in order to avoid differential signal transmission distortion, positive and negative impulse pipe should be laid as close as possible, cold regions freezing measures should be taken. Can be electric or steam heat, but to prevent overheating of the measured medium and cause vaporization produce gas in the guide tube false differential pressure. 10, orifice plate installation in vertical trail head, take the pressure port location, you can choose to take on the plane pressure device. Plates installed in the horizontal or inclined main channel, as shown in Figure IV pressure port location. 11, guided by the nature of the pressure tube and the choice of the measured medium pressure, corrosion-resistant materials of construction, which shall not be less than the inner diameter of 6 mm and a length of 16 m in the best. Table II provides a different medium pressure pipe inside diameter and length of the guide, reference available. Table II pressure guide tube inner diameter and length (mm) Impulse Impulse tube diameter tube length measured media> 16,000 16,000 - 45,000 45,000 - 9,0000 impulse pipe length guide tube diameter measured medium pressure water, steam, dry gas wet gas low, dirty oil viscosity liquids or gases 7-9 13 13 25 1,013,192,513,132,538 12 throttling device on the downstream side to ensure that there is a certain length of straight pipe, the specific requirements of Table three. β orifice upstream side of the local resistance in the form of straight pipe pieces and the minimum length l1 cutting pieces of straight pipe upstream and downstream side of the minimum length l2 (left all the pieces in the form of local resistance) a 90 ° elbow or only one branch flows tee. There are more than 90 ° bends in the same plane. Elbow space (there are more than 90 ° elbows in different planes). Diameter pipe (large to small, 2D → D, length ≥3D, small and large 1 / 2D → D, length ≥1 1/2) D. Wear fully open stop valve fully open valve 1 2 3 4 5 6 7 8 ≤0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 10 (6) 10 (6) 10 (6) 12 (6) 14 (7) 14 (7) 14 (7) 16 (8) 18 (9) 22 (11) 28 (14) 36 (18) 49 (32) 14 (7) 14 (7) 16 (8) 16 (8) 18 ( 9) 18 (9) 20 (10) 22 (11) 26 (13) 23 (16) 36 (18) 42 (21) 50 (25) 34 (17) 34 (17) 34 (17) 36 (18) 36 (18) 36 (19) 40 (20) 44 (22) 48 (24) 54 (27) 62 (31) 70 (35) 80 (40) 16 (8) 16 (8) 16 (8) 16 ( 8) 16 (8) 18 (9) 20 (10) 20 (10) 22 (11) 24 (12) 26 (13) 28 (14) 30 (15) 18 (9) 18 (6) 18 (9) 18 (9) 20 (10) 20 (10) 22 (11) 24 (12) 26 (13) 28 (14) 32 (16) 36 (18) 44 (22) 12 (6) 12 (6) 12 ( 6) 12 (6) 12 (6) 12 (6) 12 (6) 14 (7) 14 (7) 16 (8) 20 (10) 24 (12) 30 (15) 4 (2) 4 (2) 5 (2.5) 5 (2.5) 6 (3) 6 (3) 6 (3) 6 (3) 7 (3.5) 7 (3.5) 7 (3.5) 8 (4) 8 (4) Note: ① This table applies a variety of cutting pieces to this standard; ② figures listed in this table for pipe diameter "D" of multiples; ③ figures in this table are outside the parentheses as "additional limit relative error is zero," the value; Figures in brackets for "Additional limit relative error of ± 0.5%" values. Installation (two) throttling device installation is correct or not directly affect the measurement accuracy. To this end are a few installation examples for reference. 1, donut plate (Pg10, Pg25) installation, shown in figure V. Impulse tube specifications for φ20 × 6 seamless steel tubes. 2, double orifice installation shown in figure VI, guide specifications for pressure pipe φ20 × 6 seamless steel tubes. 3, fillet angle drilling alone take pressure standard orifice plate installation shown in Figure 7, the pressure tube guide specifications for the φ20 × 6 seamless steel tubes. Connection (three) throttling device with a differential pressure gauge for measuring liquid flow (1) meter installation location: the best instrument is installed underneath the throttling device, which prevents the liquid gas into the guide tube and pressure instrumentation, FIG eight (a) in Fig. If the instrument has to be installed above the throttle device, in order to reduce the gas in the liquid into the conduit and the instrument should be between the throttle device and the connecting pipe equipped with U-bend, and at least the lower end of the elbow should be lower conveying pipe centerline 0.7 m, as shown in the leading (b) in Fig. (2) Pressure on the horizontal or inclined pipeline process, if the taps open at the top of the throttle device, it will accumulate gas pressure inside the guide tube; if the opening in the bottom of the throttle device, allow the precipitate fall pressure guide tube. Therefore, the pressure tube should lead from the horizontal centerline of the horizontal cross-section leads to both ends of the throttle device or from the horizontal centerline of the two ends of less than 45 ° down leads. 2, measuring the steam flow (1) In order to avoid the effects of high temperature steam in the pipeline between the pilot pressure gauges and throttle device, you must install both on the same height of the condenser and condenser, pressure pipe and guide high and low indoor full condensate, in order to avoid adverse effects of high temperature on the instrument. (2) the best meter installed beneath the throttling device, which can prevent gas from entering the guide tube and pressure meter, condenser should be installed near the throttle at the day, as nine (a) below. (3) The meter has to be installed beneath the throttle device, the condenser should be mounted above the instrument in place, as shown in Figure IX (b) below. 3. Measurement of gas flow (1) meter installation location: should the instrument is mounted above the throttling device, so the condensate flow generated within the guide tube back pressure pipelines. FIG ten (a) in Fig. If you have installed the meter at the bottom of the throttle device, in order to reduce the moisture condensation inside the guide tube pressure from the start throttling device leads impulse tube fitted with a U-shaped pipe, the upper end should be at least 0.7 meters above the centerline of the pipeline. FIG ten (b) in Fig. (2) connecting pipe opening position in a horizontal or inclined pipeline in order to avoid condensate into the conveying pipe connecting pipe, connecting pipe section should be the upper half of the throttle device leads. (3) If the gas contained in the dirt and dust in the corner guide pressure pipe should be installed cross connector for cleaning and purging. 4, when the measurement of corrosive liquids or gases corrosive effect on the instrument measuring liquids or gases, must be equipped with an isolator between the instrument and the throttle device, in the conduit separator and after isolation were injected liquid, require isolation liquid separator liquid level in order to ensure equal measured media does not enter the instrument's high and low pressure chamber. (1) When a severe test medium is less than the heavy liquid separation, using FG-64A isolator installation Figure XI (a) below. (2) When severe severe isolation liquid is greater than the measured medium, using FG-64B type isolator is installed as shown in eleven (b) below. (D) installation requirements throttling device installation and applies to the following pipe sections and fittings related to: throttle upstream side of the first pieces of the resistance member, a second resistance element, cutting pieces to the right under the first resistance element upstream from the orifice second resistance element to the downstream of the first pipe section and the differential signal lines between the resistance and so on. Use and maintenance 1, the use of correction practice, process conditions can sometimes change, will bring measurement error, it is sometimes necessary corrections to be done. 2, when the pressure and temperature changes: pressure and temperature changes, the change will affect the medium severe. Shall be amended by the following formula: G2 = G1 Q2 = Q1 G1-- reading actual traffic flow G2-- Q1-- Q2-- actual traffic flow readings measured media design r1-- severe r2-- actual measured medium severe 3 and maintenance: throttling device and lead pressure system and front and rear pipes should be checked at least once a year, to remove dirt, replace the scrapped components to ensure its normal operation