ddtop LG User manual

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LG
ORIFICE PLATE, VENTURI,
NOZZLE FLOW METERS
Operation Manual
LG-DT-JS-1016-2018(A)

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Preface
Thank you for choosing the products of Dandong Top Electronics Instrument (Group) Co., Ltd.
This operation manual provides you with important information about installation, connection and
commissioning as well as maintenance, troubleshooting and storage. Please read it carefully before
installation and commissioning and save it as an integral part of the product near the instrument for
reading at any time.
This manual can be downloaded from www.ddtop.com.
If you do not follow this manual, the protection provided by this instrument may be damaged.
Trademarks, Copyrights and Restrictions Instructions
Dandong Top Electronics Instrument (Group) Co., Ltd.®, Dandong Top Pump Co., Ltd.®, DDTOP®
are registered trademarks of the company.
The performance specifications of this instrument are effective from the date of release, and are
subject to change without notice. Dandong Top Electronics Instrument (Group) Co., Ltd reserves the
right to modify the products described in this manual at any time without prior notice.
Quality Assurance
Dandong Top Electronics Instrument (Group) Co., Ltd guarantees that all products will be free from
defects in materials and manufacturing processes within one year from the date of leaving the
factory.
During the warranty period, if the product is returned due to quality problems, and the claim is
determined to fall within the scope of the warranty after inspection by the manufacturer, Dandong
Top Electronics Instrument (Group) Co., Ltd is responsible for repairing or replacing it for the buyer
(or owner) free of charge.
Dandong Top Electronics Instrument (Group) Co., Ltd is not responsible for the costs caused by
improper use of equipment, labor claims, direct or subsequent damage, and installation and use of
equipment. Except for the special written warranty certificate for certain products, Dandong Top
Electronics Instrument (Group) Co., Ltd does not provide any express or implied quality guarantee.
Quality
Dandong Top Electronics Instrument (Group) Co., Ltd has passed the ISO9001 quality system
certification. The entire production process is strictly implemented in accordance with the scope of
the quality system, providing the strongest guarantee for the quality of products and services.

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CONTENTS
1 Safety Tips.................................................................................................................................................4
1.1 An explosion may cause death or serious injury...............................................................................4
1.2 Process leaks can cause serious injury or death................................................................................4
1.3 Failure to follow the safety installation guidelines may result in death or serious injury. ...4
2 Product Description..................................................................................................................................4
2.1 Product Structure.........................................................................................................................................4
2.2 Operating Principle .....................................................................................................................................6
2.3 Package...........................................................................................................................................................6
2.4 Lifting Transportation.................................................................................................................................6
2.5 Storage............................................................................................................................................................ 6
3 Main Executive Standard..........................................................................................................................6
4 Main Features ...........................................................................................................................................6
4.1 The standard flow element can ensure the accuracy of measurement without calibration.
..................................................................................................................................................................................6
4.2 The measuring range is wide, and it can be applied if it is smaller than DN1000.................6
4.3 The applicable temperature range is wide: -196~650℃. ..............................................................6
4.4 The daily maintenance is small and the operation is simple.........................................................6
5 Outline Dimension Diagram....................................................................................................................6
6 Unpacking and Inspection .......................................................................................................................8
6.1 Precautions for Unpacking Inspection..................................................................................................8
6.2 Check Content ..............................................................................................................................................8
7 Installation.................................................................................................................................................8
7.1 Flow element is butt welded with the on-site pipeline to ensure the welding quality and
suppress no leakage. .........................................................................................................................................8
7.2 nstallation Technical Requirements.......................................................................................................9
8 Requirements for the Use of Flow Element..........................................................................................11
9 Fault Analysis and Troubleshooting......................................................................................................11
10 Disassemble ..........................................................................................................................................12
10.1 Warning......................................................................................................................................................12
10.2 Waste Disposal.........................................................................................................................................12
11 Product Certificate................................................................................................................................13

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1 Safety Tips
For safety reasons, it is expressly prohibited to modify or change the product without authorization.
Repair or replacement is only allowed to use the accessories specified by the manufacturer.
1.1 An explosion may cause death or serious injury.
When installing the device in an explosive environment, be sure to comply with applicable local,
national, and international standards, codes, and regulations. Ensure that the equipment is installed
in accordance with intrinsically safe or non-flammable site operating procedures.
1.2 Process leaks can cause serious injury or death.
If the process seal is damaged, the medium may leak at the connection.
1.3 Failure to follow the safety installation guidelines may result in death or serious injury.
The operations described in this manual need to be completed by professionals who have received
professional training and obtained corresponding qualifications or special end-users.
2 Product Description
2.1 Product Structure
Figure 1-1 Product Structure Diagram of Orifice Plate Flow Element
Figure 1-2 Product Structure Diagram of Nozzle Flow Element
Figure 1-3 Product Structure Diagram of Venturi Flow Element
Figure 1-1
1- Flange, Clamp Flange, Welded to Site
2- Flow Element, Flow Measuring Element
3- Fasteners, Including Bolts, Nuts, Washers

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1. Straight Pipe Section
2. Long Diameter Nozzle
3. Pin
4. Tap Short Section
Figure 1-2
1. 入口圆筒 Entrance Cylinder
2. 圆锥收缩管 Conical Shrink Tube
3. Throat Tube
4. Conical Diffuser
5. Front Equalizing Ring
6. Back Equalizing Ring
7. Tap Tube
8. Connection Flange
Figure 1-3

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2.2 Operating Principle
In the pipeline filled with single-phase continuous fluid, install a flow element (such as an orifice
plate, nozzle etc). When the fluid passes through the orifice of the flow element, the vapor forms a
local contraction, the flow velocity increases, the kinetic energy increases, and the static pressure
decreases. There is a static pressure difference between the front and back of the flow element, that
is, ΔP = P1-P2. If the area of the orifice is F, the mass flow of the fluid is qm, the volume flow is qv,
and the density is ρ, according to the principle of flow continuity and Bernoulli equation can derive
the relationship between pressure difference and fluid flow:
In the formula, α is the flow coefficient. It can be seen from the above relationship that if the orifice
area and fluid density are constant, the flow rate is proportional to the square root of the pressure
difference, that is, as long as the pressure difference is measured, the flow rate can be calculated.
The flow element measures the fluid flow rate based on this principle.
2.3 Package
Please send packaging waste to a special recycling agency.
2.4 Lifting Transportation
Please use qualified lifting equipment and lifting straps, and pay attention to safety.
2.5 Storage
Storage temperature -20℃~40℃; storage humidity ≤20%.
3 Main Executive Standard
Comply with GB/T2624-2006, ISO5167-2003, BS1042-1992 and other standards.
4 Main Features
4.1 The standard flow element can ensure the accuracy of measurement without calibration.
4.2 The measuring range is wide, and it can be applied if it is smaller than DN1000.
4.3 The applicable temperature range is wide: -196~650℃.
4.4 The daily maintenance is small and the operation is simple.
5 Outline Dimension Diagram
The dimensions of D and L in the picture are subject to the actual product.
Figure 2-1 Schematic diagram of dimensions of the orifice plate flow element

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Figure 2-2 Schematic diagram of dimensions of the nozzle flow element
Figure 2-3 Schematic diagram of dimensions of the venturi flow element.
Figure 2-1
Figure 2-2

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Figure 2-3
6 Unpacking and Inspection
6.1 Precautions for Unpacking Inspection
6.1.1 Check whether the product nameplate (Figure 3) is consistent with the supply list information.
Figure 3 Product Nameplate
6.1.2 Check the quantity and material of each part against the packing list.
6.2 Check Content
6.2.1 Check whether the appearance of the instrument is defective or damaged.
7 Installation
7.1 Flow element is butt welded with the on-site pipeline to ensure the welding quality and

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suppress no leakage.
7.2 nstallation Technical Requirements
7.2.1 When installing the flow element, pay attention that the direction of the inlet and outlet is
consistent with the direction of the mark on the nameplate and the direction of arrow label. Do not
install it backwards. Printing mark surface of the handle is the upstream side (Figure 4)
图4
Figure 4
7.2.2 The gasket shall not protrude into the inside of the pipe after clamping.
7.2.3 The valve used to adjust the flow should preferably be installed outside the shortest straight
pipe downstream of the flow element (Figure 5).
Figure 5
7.2.4 There shall be no sudden changes in pipe diameter at the connection of each pipe section and
pipe fittings of the flow element.
7.2.5 For newly installed piping systems, the flow element must be installed after piping flushing and
line sweeping.

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7.2.5.1 When the measurement accuracy is high, it is best to assemble the flow element, the tapping
device and the upstream and downstream straight pipe sections first, and then connect to the
process pipeline after passing the inspection (Figure 6).
Figure 6
7.2.5.2 Each high point of the tapping signal pipeline must be equipped with a vent valve (Figure 7),
and each low point must be equipped with a drain valve (Figure 8).
Figure 7

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Figure 8
8 Requirements for the Use of Flow Element
8.1 The fluid must be filled with round pipes and throttling devices, and flow through the pipes
continuously;
8.2 The fluid must be a Newtonian fluid, which is homogeneous, single-phase in physics and
thermodynamics, or can be considered single-phase; including gas, liquid and steam, etc.;
8.3 No phase change occurs when the fluid flows through the flow element;
8.4 The fluid flow rate does not change with time, or changes slowly;
8.5 Before the fluid flows through the flow element, its stream must be parallel to the axis of the
pipeline, and there must be no rotating flow;
8.6 The standard flow element is not suitable for flow measurement of pulsating flow and critical
flow.
9 Fault Analysis and Troubleshooting

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Failure
Phenomenon
Reason
Method
Differential pressure
transmitter indicates
no change
1. Stop valve is not opened
Open the stop valve
2. differential pressure pipeline is blocked
Unblock the differential pressure pipeline
3. Differential pressure transmitter failure
Check differential pressure transmitter
The indication value of
the differential
pressure transmitter
obviously deviates
from the indication
value of the gauge
1. The installation direction of the flow
element is wrong
Reinstall flow element
2. Differential pressure transmitter failure
Check differential pressure transmitter
3. The working condition parameters of the
measured medium are inconsistent with
those used when designing the flow
element
Communicate with the company
after-sales service
4. The length of the straight pipe before
and after the flow element is not enough
Adjust straight pipe section length
5. The inner diameter of the straight pipe
section is out of tolerance
Measure the inner diameter of straight
pipe section and recalculate the
maximum flow
6. Throttle aperture tolerance
Measure the throttle aperture, recalculate
the maximum flow
7. Deformation of flow element
Replace flow element
8. There are attachments on the flow
element
Clean and replace flow element
9. Improper installation of tapping signal
pipeline
Retake the tapping signal pipeline in the
correct way
10. The condensate level in the condenser
varies.
Adjust the condensate level to make the
height uniform.
Differential pressure
transmitter has no
indication
1. Power supply is not turned on
Turn on power supply
2. Stop valve is not opened
Open the stop valve
3. Differential pressure transmitter failure
Check differential pressure transmitter
Medium leakage at the
flow element
1. Insufficient clamping force of connector
Refasten the connection
2. Sealing gasket failure
Replace the gasket
3. Material is corroded
Replace corroded parts
10 Disassemble
10.1 Warning
Before disassembling, pay attention to dangerous process conditions, such as pressure, high
temperature, corrosive or toxic media in the container, etc.
10.2 Waste Disposal
Please follow the current regulations in each region for waste disposal.

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11 Product Certificate