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Jiangsu Borui Measurement and Control Technology Co., Ltd

E-mail
wxbrck@ 163.com
Phone
13812024099
Address
No. 35 Xigang East Road, Xishan District, Wuxi City

Platinum Rui throttling device orifice flowmeter - Wuxi Platinum

NegotiableUpdate on 09/10

Model

Nature of the Manufacturer: Producers

Product Category

Place of Origin

Online Consult

Overview

1、 Product Overview Orifice flowmeter, also known as differential pressure flowmeter, is composed of a primary detection element (throttling element) and a secondary device (differential pressure transmitter and flow display instrument), widely used for flow measurement of gases, vapors, and liquids. Has a simple structure ..

Product Details

1、 Product Overview

The orifice flowmeter with throttling device, also known as differential pressure flowmeter, consists of a primary detection element (throttling element) and a secondary device (differential pressure transmitter and flow display instrument), and is widely used for flow measurement of gases, vapors, and liquids. It has the characteristics of simple structure, easy maintenance, stable performance, and reliable use. The orifice plate throttling device is a standard throttling component that can be produced directly in accordance with national standards without calibration. 1. National standard GB2624-81<Design, installation, and use of flow measurement throttling devices; 2. International standard ISO5167<Various throttling devices specified by the International Organization for Standardization; 3. Ministry of Chemical Industry standard GJ516-87-HK06. 2、 The working principle is that the fluid filled in the pipeline flows through the throttling device inside the pipeline, causing local contraction near the throttling element, increasing the flow velocity, and creating a static pressure difference on both sides upstream and downstream. Under the condition of known parameters, the relationship between differential pressure and flow rate can be derived based on the principle of flow continuity and Bernoulli equation to obtain the flow rate.

2、 Purpose, characteristics, and scope of application

1. Purpose: The throttling differential pressure flowmeter consists of three parts: throttling device, differential pressure transmitter, and flow accumulator. The throttling device is a primary element directly installed on the pipeline, and the differential pressure transmitter and integrator are secondary elements. It is mainly used for the flow of various gases (pure or dusty), steam (saturated or superheated), and liquids (conductive or non-conductive; highly corrosive; viscous or containing tiny particles of dirt) through pipelines. It can directly measure volumetric flow rate or mass flow rate.

2. The usage conditions, characteristics, and scope of application of differential pressure flowmeter (standard orifice plate)

a、 Usage conditions:

1. In the measurement section, the fluid must fill the circular tube and continuously flow through the throttling device;

2. The fluid must be a homogeneous single-phase fluid both physically and thermodynamically;

3. The fluid measured by the throttling device must be a stable flow, or can be regarded as a stable slowly changing fluid, and is not suitable for pulsating flow and critical flow measurement;

b、 Characteristics and scope of application:

1. The standard throttling device does not require real flow calibration to ensure its measurement accuracy. (Unique among all flow meters);

2. It is widely applicable to the measured medium and can be used for flow measurement of almost all gases, vapors, and liquids;

3. Applicable diameter ratio β is 0.22-0.75, Reynolds number ReD ≥ 5000, pipeline diameter DN50~1000mm, allowing extrapolation to 5000mm. β=d/D, d - orifice plate opening diameter; D - Actual inner diameter of pipeline

4. The pressure can reach up to 32MPa and can also be used for negative pressure;

5. Medium temperature range: -30 ℃ to+650 ℃;

6. The intelligent differential pressure flowmeter adopts an intelligent differential pressure transmitter, which can set the differential pressure value (within the specified range) on site through buttons or communication methods according to the changes in the flow rate of the measured object, thereby changing the flow range and greatly expanding the system flow range;

7. No movable parts, the mechanism is safe and reliable, easy to use and operate, easy to master, and maintenance free;

According to the national standard GB/T2624-93 of the People's Republic of China and the international standard ISO5167-1, the flow range ratio applicable to throttling devices is 3 (i.e. the ratio of maximum and minimum applicable flow rates). In some cases, a range ratio of 4 is allowed. If the range ratio is greater than the above value, the measurement error at low flow rates using the same differential pressure meter will be significant.

3、 Classification and structural diagram

1. Classification

① Classified by flange clamping method
1. Welding type 2, flange clamping type

② Classified by pressure collection method

1. Corner drilling for pressure measurement; 2. Pressure measurement for corner joint chamber 3 and flange pressure measurement; 4. Radial pressure measurement;

2. Structure and schematic diagram

① Figure 1 Structure diagram of standard annular orifice plate throttling device

1. Flange 2, pressure pipe 3, front ring chamber 4, throttling element 5, rear ring chamber 6, sealing gasket 7, bolt 8, nut

Figure 1

4、 Structure and schematic diagram

1、 Various standard orifice plate structures, as shown in Figure 2

Figure 2

5、 Product selection

model	Type spectrum description
BR	enterprise standard
	LG	Flow throttling device
		code name	pressure tapping method
		H	Pressure measurement of corner joint chamber
		Z	Corner drilling for pressure measurement
		F	flange taps
		J	Radial pressure measurement
			code name	Description of throttling device
			K	standard orifice plate
				code name	Nominal Pressure
				-0.6	0.6
				-1	1
				-1.6	1.6
				-2.5	2.5
					code name	Nominal diameter
					DN10	DN10~DN50 (threaded, flange)
					DN50	DN50~DN800 (flange)
						code name	flange material
						C	carbon steel
						P	stainless steel
						H	alloy steel
							code name	medium
							1	liquid
							2	gas
							3	steam
								code name	Attachment
								N	Excluding attachments
								F	Equipped with three valve groups, etc
								I	Equipped with F and transmitter (accessories can be selected according to the medium and requirements)
								DC	Equipped with F and multi parameter transmitter
								O	User specified configuration attachments

6、 Installation skills

1. Approved parameters: Before installation, it is necessary to verify the on-site operating conditions and confirm that all parameters in the throttling device calculation sheet are exactly the same as the operating conditions at the installation point. Otherwise, necessary corrections or compensations must be made.

2. Direction: There are "+" and "-" marks on the handle of the orifice plate or the outer surface of the flange of the throttling device, respectively. "+" represents the upstream side (facing the direction of the fluid) and must not be installed in reverse.

3. Insertion depth: The pressure tapping hole plate in the ring chamber is inserted at a depth of 2-5mm between the pipeline and the ring chamber, but the pipeline cannot be pushed into the ring chamber, otherwise the pipeline will expand due to heat and damage the ring chamber. Drill a pressure tapping hole plate, and the pipeline protruding into the hole plate must not block the pressure tapping hole at any point.

4. System blowing: After the installation of the throttling device is completed, it should be blown. At this time, the throttling element (orifice plate) should be removed first to prevent debris in the pipeline from scratching the orifice plate or blocking the pressure pipe. After the blowing is completed, it should be installed in the same direction as the arrow on the orifice plate and the direction of fluid flow. Pay attention to tightening to ensure sealing.

5. Zero adjustment: After the purging and installation are completed, open the middle valve of the three valve group. At this time, the differential pressure value should be zero. If not, it must be reset to zero. The method is to hold down the button in the lower left corner for 20 seconds and release it.

6. Finally, slowly close the middle valve of the three valve group (it must be tightly closed), open all the shut-off valves on the upper part of the positive and negative pressure pipes, and the orifice plate can work normally.

7. Installation coaxiality requirements: The throttling element and the pipeline must be concentric, with an eccentricity distance of no more than 0.0025D. Users should pay attention to or take necessary measures during welding operations.

8. Orifice plates are generally used in conjunction with differential pressure transmitters. When connecting the pressure conduit to the differential pressure transmitter, attention should be paid to not installing the positive and negative pressures in reverse, with "H" indicating positive and "L" indicating negative;

9. The pressure pipes led out from the positive and negative pressure ports must be kept parallel in any situation;

10. If a regulating valve must be installed, it is recommended to install the regulating valve after the required length of the straight pipe section on the downstream calculation sheet.

11. When the measured medium is gas or steam and there are significant fluctuations in temperature and/or pressure, temperature and/or pressure compensation should be performed. The pressure transmitter is installed at 1D upstream, and the thermocouple is installed at 1D downstream.

12. There should be no bag shaped space on the differential pressure signal pipeline where liquid or gas may accumulate. If unavoidable, a gas collector (or exhaust valve) and a settling device (or drain) should be installed.

13. Zero drift of the transmitter can also cause measurement errors, and the differential pressure transmitter should be calibrated regularly during use.

14. In addition to regularly inspecting the pressure pipes to prevent blockage, outdoor pressure pipes should be properly insulated to prevent solidification or freezing. If the pipeline (vertical section) is quite long, false pressure difference caused by temperature difference should be avoided. At this time, it is recommended to lay two differential pressure pipelines close to each other and wrap them together in the insulation layer.

15. Differential pressure pipelines should have brackets to prevent vibration and strong forces from acting on the differential pressure gauge.

16. When hoisting the throttling device on site, it is strictly prohibited to use iron wire, steel wire, or hook to penetrate the throat hole of the throttling element to prevent sharp mouth damage and affect accuracy;

17. After using the throttling device for a period of time, due to the presence of solid particles in the liquid and liquid droplets or other impurities in the gas, the sharp inlet will be blunted, resulting in an increase in the outflow coefficient and additional errors. At this time, it is necessary to consider replacing the throttling element; In addition, after long-term use, the throttling device is prone to accumulate dirt at the lower corner of the upstream side of the orifice plate, which can cause changes in the outflow coefficient. Therefore, regular inspections should be carried out to eliminate dirt.

18. Pressure tube: The material of the pressure tube should be determined according to the properties and parameters of the measured medium. If the inner diameter is too small or the length is too long, it will cause serious signal lag or distortion. It is recommended to refer to Table (1) for determination.

Table 1: Inner Diameter and Length of Pressure Pipe