Product FAQs and handling
1. The amount of field instrument frequency change is large, and
the elimination method is as
follows:
2. A:First check whether the straight pipe section meets the
requirements, and the gas can be
relaxed to ensure the straight pipe section of the front 10D and
the rear 5D.The straight pipe section
does not meet the requirements, and the straight pipe section is
not long enough. It is recommended
to change the installation position.There may be electromagnetic
interference at the scene. Method:
Enhance the filtering function and lower the sensitivity by dialing
the code switch.C. The on-site
flow is too small, below the lower limit of the meter,For example,
the 300-gauge plug-in gas has a
19 lower limit of 1500 m3/h, but the field indicates an
instantaneous flow of about 500 m3
. Since theflow rate is at the lower limit, the value does not
change linearly. The flow rate can be increased by
changing the meter factor (not recommended).D. A similar situation
can occur when measuring the
pulsating flow of a liquid.
3. There is 50HZ interference at the site, generally the shielded
cable is not grounded.
4. No flow signal at the scene. A. The instrument small signal cut
is too large, can be modified
in the parameter setting; B. The power supply is not connected, no
power; C. The flow rate is very
low and the signal trigger point is not reached; the D.4-20mA
output table is not set before leaving
the factory.
5. The actual flow rate increases, but the meter display decreases,
checking the cause of the site
conditions (such as pipeline process, etc.).
6. The actual flow is reduced, but the meter display is increased,
most of which is pipe
vibration or the gasket is not at the center of the pipe during
installation. The instrument should be
reinstalled.
7. The meter display of the same working condition is inconsistent,
and the difference is large. A. The customer's experience value is
wrong, or the working conditions are different, such as the
problem of the pipeline, the problem of the straight pipe, the
problem of vibration, etc.;B. The
parameters have been modified by the customer; C. The flow rate is
too low, the lower limit is not
linear; D. The temperature and pressure compensation table, the
temperature pressure is faulty.
8. The instrument with 4-20mA output is inconsistent with the
system display. A. The unit of
parameter setting is inconsistent, or the range is not consistent;
B.4-20mA output cable is too long
(more than 1000 meters), and the loss is large.
9. The flow displayed by the meter differs greatly from the actual
one, and most of the reason is
the problem of the parameter setting unit.
10. Most of the static flow of the instrument is caused by
vibration of the pipeline in the field. Damping measures or
reducing the sensitivity of the instrument can be alleviated or
eliminated.
Product description
The vortex flowmeter manual records how to use the product
correctly and safely.Please read
this manual carefully before installation and debugging in order to
prevent the instrument from being
damaged or unable to perform its best performance and ensure the
stable operation of the instrument. Step 1: open the box inspection
must read
1. Check the packing list to see whether the accessories are
complete. 2. Appearance inspection to see if the instrument is
complete and damaged due to
transportation;
3. Power test. If the battery is powered up, turn on the switch to
check the display state of the
meter.4. Check whether the installation accessories are complete
and prepare for installation. Step 2: read the installation steps
1. Choose an appropriate installation environment. The ambient
temperature should be
-20-55℃, and the ambient humidity should be within the range of
5%-90%. See 6.1 installation
environment requirements for the instrument for details;
2. Welding the product accessories, instruments should not be
online welding (flange clamping
instrument),Online welding may cause sensor thermal damage;
3. Purge the pipeline to ensure that there is no residual welding
slag in the pipeline;
4. Install the instrument, pay attention to the direction sign of
the instrument, prohibit reverse
installation, ensure that the front and rear straight pipe meet the
requirements,See installation
requirements of instrument pipelines in 6.2 for details;
5. Open the front valve slowly to prevent air hammer or water
hammer phenomenon from
hurting the instrument;
6. Pipeline pressure test and leak detection to ensure that the
pipeline does not leak;
7. Air tightness test to ensure that the installation instrument
meets the sealing requirements;
8. Slowly open the back end valve to ensure stable flow field of
medium passing through;
9. Instrument for normal operation;
10. Intallation environment should avoid violent vibration,
vibration environment will lead to
unstable flow or static flow.In the case of slight vibration, pipe
fastening device can be installed at
the upstream and downstream 2D position, and soft connection can be
installed at the connection
place with the fan and other equipment. 11. The installation
diagram of vortex flowmeter is as follows:
Features
1. The main body of the product has no moving parts,high
reliability,long-term stability,simple
structure and easy maintenance. The output of the sensor is the
pulse frequency, and its frequency is linear with the actual flow
of
the measured fluid, there is no drift at zero, and the performance
is very stable. The structure forms are various, including pipe
type, plug type flow sensor and so on. The measurement accuracy
of conventional liquid is ±1.0%.The accuracy of the gas
measurement was ±1.5%；
2. The pressure loss is small (about 1/4 to 1/2 of orifice
flowmeter), which belongs to
energy-saving flow meter;
3. Flexible installation mode, can be horizontal, vertical or
inclined to different angles according to
different process pipeline；
4. Circuit adopts a variety of protection mode, anti-surge, strong
adaptability；
5. High precision probe, piezocrystalline vortex sensor, stable
signal.The 316L stainless steel
sensor shell has strong corrosion resistance and good
intercrystalline corrosion resistance. It also
has good corrosion resistance to alkali solutions and most organic
and inorganic acids；
6. Long life lithium battery: equipped with 3.6v high poly lithium
battery, with high storage energy
density, the service life of more than 1 year；
7. Products high and low temperature adaptability, environmental
protection and other advantages；
8. Wide measuring range, measuring range ratio up to 1:10-25；
9. Within a certain Reynolds number range, the output signal
frequency is not affected by the
physical properties and component changes of the fluid, and the
instrument coefficient is only
related to the shape and size of the vortex generator,There is no
need to compensate when
measuring the volume flow rate of the fluid condition
Working principle
Vortex flowmeter is a speed-type flowmeter produced according to
karman's vortex principle, which can be used for the measurement
and metering of conventional gas, steam and liquid.Vortex
flow sensor has high precision and wide range ratio, no moving
parts in use, which can improve
mechanical stability and reduce maintenance.Vortex flowmeter is
almost not affected by the
temperature, pressure and composition of medium when measuring the
volume of working condition. Therefore, it is convenient to
calibrate the instrument, so vortex flow meter is widely used in
production and life.
Karman Vortex
Alternating and regular vortex rows are formed downstream of the
vortex generator. Assume that the frequency of vortex occurrence is
f, the average speed of the flow of the measured medium is V, and
the width of the vortex generating body's upstream surface is d.
According to the Karman vortex street principle, there is the
following relationship:
f=StV/d formula (1)
In the formula:
f - Karman vortex frequency HZ generated on one side of the
generating body
St-Strauhal number (dimensionless number)
V-Average flow velocity of fluid (m/s)
d-width of vortex generator (m)
It can be seen that the instantaneous flow rate can be calculated
by measuring the Kaman vortex separation frequency. Among them,
Strohal number (St) is a dimensionless unknown number,
The figure below shows the relationship between Strouhal number
(St) and Reynolds number (Re).
Strouhal number and Reynolds number
In the straight part of St=0.17 in the curve table, the vortex
release frequency is proportional to the flow rate, which is the
measurement range of the vortex flow sensor. As long as the
frequency f is detected, the flow rate of the fluid in the pipe can
be obtained, and the volume flow rate can be obtained from the flow
rate V. The ratio of the measured pulse number to the volume is
called the instrument constant (K), see formula (2)
K=3600f/Q(1/m³) Formula (2)
In the formula: K=instrument constant (m-3).
f=number of pulses
Q=volume flow (m³)
FAQ
1. Q: What information need to be provided to choose the suitable
model?
A: Application field, Nominal pressure ,Medium & medium temperture
, Power supply , Output,
Flow range, Accuracy, Connection and other parameters.
2. Q: Are you a trade company or a manufacturer?
A: We are an ISO approved manufacturer specialized in level and
flow measuring instruments.
OEM & ODM service are available. Welcome to visit us in China.
3. Q: What is your MOQ?
A: To start our cooperation, sample order is acceptable.
4. Q: What is your delivery date for the Intelligent Mini Micro
Turbine Fuel Oil Diesel Flow Meter?
A: The delivery date is about 3-15 working days after receipt of
payment.
5. Q: What is your payment terms?
A: We support T/T, PayPal ,Western Union.
For mass production order, it is 30% deposit in advance and 70%
balance before shipment.
6. Q: Do you have a warranty for the Flow Meter?
A: Yes, we have the warranty of 12 months.
