Wedge Flow Sensor

The throttling element of wedge flow meter is a “V” shape block, its smooth apex angle is downwards, which does not cause the liquid with suspending particles or the viscous liquid staying at the upstream of the throttling element. The wedge flow meter can measure the liquid flow rate with high viscosity. For the process of large pipe size with low flow rate, the wedge flow meter has great advantage, it is specially suitable for volume flow and mass flow measurement in the industry of petroleum and chemical.

Product Description

Principle:

According to Bernoulli’s formula, the flowing fluid obeys the law of conservation of energy, that is the sum of the kinetic energy and the static energy is constant. When the fluid is passing the “V” shape block, the flow area reduces, the flow velocity increases, the static pressure reduces, which produce the static pressure difference, the pressure difference’s square root is in direct proportion with the flow rate, so measure the differential pressure can calculate the flow rate. The wedge flow sensor is non-standard part, so every wedge flow meter must be calibrated with the fluid before leaving factory.

principle

The flow rate (Qx) calculating formula as follow:

formula

Qx: Volume flow rate, (Unit: m3/s)
C: Discharge coefficient
ε:Expandable coefficient
m: Throttling area ratio
D: Pipe Inner Diameter ( Unit: m )
△P : Differential pressure ( Unit: Pa )
ρ:Process density of the fluid (Unit: Kg/m3 )

Product features:

● Especially suitable for flow measurement of the liquid with high viscosity, low Reynolds number or the liquid with suspend substance and bubbles.
● The permanent pressure loss is lower than that of orifice plate.
● The wedge structure has the function of guiding the flow and anti blocking.
● Compensation to viscosity variation, temperature variation, density variation.
● Anti-Vibration, anti-strike, anti-smudgy.
● With the function of bidirectional measurement.
● Good repeatability, after calibration, accuracy is 1.0% ~ 1.5%.
● Simple structure, no movement part, wear-resisting, no need of re-calibration during long term using.
● Anti-corrosion metal material available for the wedge type flow sensor and using DP transmitter with remote seal.

Technical parameters:
Nominal diameter DN15 ~ DN300 (Special order for size above DN300)
Accuracy ± (1.0 ~1.5) % FS
Turn down ratio 15:1
Operation pressure -0.1 Mpa to 6.4Mpa
Operation temperature -50 to 400 ℃
Measurable minimum flow rate 0.01 m/s
Up limit of process viscosity 500 mPa.s
Reynolds number range 300 ~ 1 x 10^6
Applicable fluid water, waste water, gas, steam, high viscosity liquid, Solid & liquid mixture

 

Installation and using

(1) Make sure the fluid which is close to the upstream of wedge flow sensor is fully developmental turbulent flow and no swirls.
(2) Make sure the average inner diameter’s error in at least 2 x DN length of pipe at the upstream of the wedge flow sensor not excess±3% of the average pipeline’s inner diameter.
(3) The wedge flow meter can be installed on the horizontal or vertical pipeline with same nominal diameter. The pipeline’s inner wall shall be smooth and no attached substance. If the flow sensor is vertical mounting, the fluid shall flow from down to up, shall make the flow meter can exhaust the air bubbles conveniently to avoid the instrument’s zero point drifting.
(4) The installation diagram of the wedge flow meter as follow:

installation diagram

(5) The upstream and downstream of the wedge flow meter shall be configurated with straight pipe, different wedge ratio request different straight pipe length at the upstream of the wedge flow meter, please refer to the following table:

Wedge ratio
( H/D )
The requested straight pipe length at the upstream of the wedge flow meter, if the upstream is respectively elbow 90°, Tee pipe, ball valve, gate valve.
Elbow 90° Tee pipe Ball valve Gate valve
( Full open )
0.2 ≥ 6D ≥ 6D ≥ 10D ≥ 6D
0.3 ≥ 8D ≥ 8D ≥ 11D ≥ 6D
0.4 ≥ 12D ≥ 12D ≥ 14D ≥ 8D
0.5 ≥ 14D ≥ 14D ≥ 16D ≥ 10D
Remark:  D is the inner diameter of the wedge flow sensor’s meter tube.

 

 

 

FAQ

Answer : Please send your question or enquiry to our email: sales@hginstrument.com, we will forward the questions to the related engineer.

Answer :  Please communicate with the sales about the return procedure before returning product.

Answer :  The delivery time depends on the order quantity and product specification.  If the product’s specification is conventional ( not special ),  delivery time is 5 or 7 working days for order quantity ≤ 10 pieces;  delivery time is 2 or 3 working weeks for order quantity 15 ~ 30 pieces. 

Answer :  by Courier,  by Sea or by Air

Answer :  Yes,  Generally warranty is one year.

Answer :  From year 2015  to year 2021,  average annual sales is RMB 350 million ( about USD 54.7 million )

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