A throttling device is also called a throttling flowmeter. A typical differential pressure flow meter. Commonly used to measure the flow of gas, liquid and steam in industrial production.

Features of Throttling Device

• The throttling device has the advantages of simple structure, firmness, reliable work, stable performance, high degree, and low price. Therefore, the amount of throttling device has an advantage compared with other flow meters.
• Wide range of pipe diameter, φ2～φ3000mm (or larger). The cross-sectional shape, round or rectangular shape is acceptable.
• The standard throttling device can determine its measurement degree without real flow calibration.
• Applicable to a wide range of tested media. It can be used for almost all gas, steam and liquid flow measurement.
• The working pressure can be as high as 32Mpa. Can also be used for negative pressure.
• Medium temperature range: -l85～+650℃. Other flowmeters are not yet possible.
• The structure of non-standard throttling device is diverse. Almost applicable to various fluid flow measurement.
• The flow range can be changed on site by setting the range of the differential pressure transmitter.
• It is simple to use, operate, easy to master, and daily maintenance is small.

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Throttling Device type and composition

The throttling device consists of throttling parts (such as orifice plate, nozzle, etc.). Pressure Sensors, fastening devices (flanges, bolts, nuts, gaskets, etc.), and other accessories (pressure guiding tubes, stop Valve, etc.). It can also be equipped with front and rear measuring tubes and flanges at both ends of the straight pipe section.

Throttle Parts

Code	Name	Code	Name	Code	Name
A	Restrictor orifice	K	Wide Edge Orifice	T	Machined Venturi
B	Standard orifice or eight-slot orifice	L	Venturi nozzle	U	Wedge flowmeter
C	Long diameter nozzle	M	Small nozzle	V	V cone flowmeter
D	End orifice plate	N	Orifice plate	W	Rough welded iron plate venturi
E	1/4 arc orifice (nozzle)	O	Eccentric orifice	X	Rough cast venturi
F	Low pressure loss flowmeter	P	ISA1932 nozzle or eight-slot nozzle	Y	Double orifice plate
G	High pressure lens aperture plate	Q	Round hole plate	Z	Averaging tube flowmeter
H	Annular orifice	R	Conical inlet orifice
J	Wing type wind measuring device	S	Double venturi

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Pressure method

Code	Name	Code	Name
H	Corner connection pressure (ring chamber)	J	Diameter pressure
Z	Corner connection pressure (drilling)	T	Special pressure
F	Flange pressure

Note: The current limiting orifice has no such representation method

Diameter

Code	2	3	4	5	6	8	10	12	15	17	20	22	25
Diameter (mm)	25	32	40	50	65	80	100	125	150	175	200	225	250
Code	27	30	32	35	37	40	45	50	60	70	80	90	99
Diameter (mm)	275	300	325	350	375	400	450	500	600	700	800	900	1000

Pipe diameter greater than 1000 is expressed as 1/10 of the actual pipe diameter

Nominal pressure

Code	0	1	2	3	4	6	10	16	20	25	32	40
Nominal pressure(Mpa)	0.6	1	1.6	2.5	4	6.4	10	16	20	25	32	42

The special nominal pressure is filled in according to the actual design pressure value

Supply method

Code	Supply content
A	Complete device with front 10D and rear 5D measuring tubes (including connecting flange and process flange)
A1	Complete device with front 10D and rear 5D measuring tube (including connecting flange)
A2	Complete device with front 10D and rear 5D measuring tube (pipe end inverted bevel)
B	A complete set of equipment with upstream and downstream measuring tubes (including process flanges) according to petrochemical standards (HGJ516-87)
B1	According to the petrochemical standard (HGJ516-87), a complete set of equipment with upstream and downstream measuring pipes (pipe end inverted bevel)
B2	According to the petrochemical standard (HGJ516-87), a complete set of equipment without upstream and downstream measuring tubes
C	According to the standard of the Ministry of Electric Power (GD87-1101) a complete set of equipment with upstream and downstream measuring tubes
D	Flanges, ring chambers or pressure-taking flanges, throttles, pressure pipes, fasteners and other complete sets of devices without measuring tubes
E	Single throttle

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The principle of Throttling Device flow measurement

The throttling device artificially causes throttling in the pipeline through which the medium circulates (as shown in the figure). When the measured medium flows through the throttling device, it causes a local contraction. The stream is concentrated, the flow velocity increases, and the static pressure decreases.

Therefore, differential pressure is generated between the upstream and downstream sides of the throttle. There is a certain functional relationship between this differential pressure and the flow rate. The greater the flow, the greater the differential pressure generated. Therefore, the flow can be measured by measuring the differential pressure.

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Throttling Device Types

As the most important branch of the flow meter, the throttling device is divided into two categories: standard throttling devices and non-standard throttling devices.

Standard throttling devices include: standard orifice plate, ISA standard nozzle, long neck nozzle, classic venturi tube and venturi nozzle;

Non-standard throttling devices include: annular orifice plate. Quarter circle nozzle. Quarter circle orifice plate. Conical inlet orifice plate. Round missing orifice plate. Eccentric orifice plate. Double orifice plate. Low pressure loss flow tube. Rectangular venturi tube, V-cone flowmeter, wedge flowmeter, built-in orifice, restrictive orifice, etc.

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Orifice Throttle Flow Meter

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Sino-Inst offers Throttling Devices. A wide variety of Throttling Device options are available to you, such as brass, carbon steel. You can also choose from free samples.

Sino-Inst is an Throttling Device supplier. Orifice plate flow meter products are most popular in Domestic Market, Southeast Asia, and Mid East.

You can ensure product safety by selecting from certified suppliers, including 375 with ISO9001, ISO14001, and Other certification.