Yenen LPG Flow Meter User manual

LPG Flow Meter
Installation and Operation Manual
Manual: LPG Flow Meter IOM
Manual code: LFM-02-e
Number of pages: 19
Issue date: August 23, 2004
Review number: 7
Last review date: December 26, 2018

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Table of Contents
Page
1.0 About this manual .......................................................................................................................3
1.1 Accuracy requirements ...............................................................................................................3
1.2 Safety precautions ......................................................................................................................3
1.3 Yenen LPG meters......................................................................................................................4
1.4 Documentation............................................................................................................................5
2.0 Installation of the meter...............................................................................................................5
2.1 Meter specifications ....................................................................................................................5
2.2 Installation requirements.............................................................................................................6
2.3 Meter dimensions........................................................................................................................8
2.4 Hydraulic part of LPG measuring systems..................................................................................9
2.5 Meter startup and operation......................................................................................................10
2.6 Meter maintenance ...................................................................................................................10
2.6.1 Procedure for relieving internal pressure..............................................................................10
2.6.2 General maintenance............................................................................................................12
2.6.3 Changing rotation direction of the meter...............................................................................13
2.6.4 Adjusting the accuracy..........................................................................................................14
3.0 Rules to consider during transportation and shipping...............................................................15
Appendix A –DOs and DON’Ts............................................................................................................16
Appendix B –Torque table....................................................................................................................18
The following symbols are used throughout this manual to alert you to important safety hazards and
precautions:
Notice: indicates a special comment or instruction.
Warning: Indicates the presence of a hazard that can cause severe personal injury or property
damage if not observed carefully.
This manual provides instructions and guidelines. The remarks and warnings inform
the operator of the hazards involved in working with Yenen meters.
Reading these instructions and preventing hazardous situations is strictly in the hands of the operator of
the equipment. Neglecting this responsibility is not within the control of Yenen.
No part of Yenen manuals may be reproduced, transmitted, transcribed, stored in a retrieval system, or
translated into any language in any form, by any means, without Yenen’s prior written permission.
Yenen reserves the right to change the specifications of the products described in this manual at any time and
without prior notice.
Yenen cannot and will not be held liable for any damages resulting from the use of this product.
While every effort has been made to ensure that the information in this manual is accurate and complete,
Yenen shall not be held liable for errors contained herein or for incidental or consequential damages in
connection of the use of this manual.
The logo(s) of Yenen Engineering Ltd. are property of Yenen Engineering Ltd.
Yenen Engineering Ltd. is ISO9001:2015 certified. For a copy of Yenen’s quality policy and / or Yenen’s
HSSE policy, please, email to [e-mail] or fax your request to [phone].

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1.0 About this manual
This manual provides instructions and guidelines. The remarks and warnings inform the operator
of the hazards involved in working with Yenen meters.
Reading these instructions and preventing hazardous situations is strictly in the hands of the operator
of the equipment. Neglecting this responsibility is not within the control of Yenen.
This installation and operation manual is intended for LPG dispenser makers and field service
personnel. It provides basic understanding of installing and maintaining Yenen LPG flow meters. It is
not all inclusive. Therefore operators of Yenen LPG meters should both be trained and authorized by
Yenen or should have prior dispenser assembly and service experience.
1.1 Accuracy requirements
Depending on local regulations, standards and codes, accuracy requirements differ from country
to country. Proper understanding of these local regulations is essential before assembling and
servicing meters and dispensers.
Yenen meters comply with the Measuring Instruments Directive 2004/22/EC (MID), which states
the following for auto gas (LPG) dispensers:
Accuracy class 1.0.
Environmental class M2/E1
Maximum permissible error 1.0%
1.2 Safety precautions
Only trained and qualified personnel familiar with handling liquids under pressure, such as LPG,
may service Yenen equipment.
ALWAYS disconnect and lock power supply before starting to service the meter and other
hydraulic parts.
Make sure that all necessary safety precautions have been taken. Make sure that proper
ventilation, fire prevention, evacuation and fire procedures are provided.
Provide easy access to fire extinguishers. Understand and adapt all local safety codes.
Read this manual as well as other available literature and drawings.
See appendix A: DOs and DON’Ts
In the event of a gas leak:
1. Stop the leak by closing the nearest valve or shut-off device.
2. Use protective clothing to prevent cold burns.
3. Prevent accidental ignition.
4. Beware that LPG is heavier than air and therefore seeks lower level.
5. Evacuate all people from the danger zone.
6. Ensure that the area is safe before resuming the operation. If in doubt, notify the local fire
department.
In the event of a gas fire:
1. Stop the leak if it is within safe reach.
2. Notify the local fire department if it is a large fire that cannot be controlled safely.
3. In case of a small, contained fire, use the appropriate extinguisher. If in doubt, notify the local
fire department.

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1.3 Yenen LPG meters
The Yenen LPG flow meter is used in a hydraulic set for LPG measuring systems, such as
dispensers for auto gas. The meter is a liquid measuring device. This volume-measuring device
operates with four pistons. The flow measurement is performed by positive displacement of four
cylinder volumes by oscillating piston movement.
Cylinder x
Crankshaft
Adjustment
Inlet
Carbon
Plate
Distribution
Valvet
Magnetic
Coupling
Figure 1: Cross-section drawing of Yenen LPG Flow meter
LPG (liquid) passes through four cylinders transforming flow energy into a piston motion. Fluid
displacement happens simultaneously. As fluid enters, another portion of the fluid is being
submitted into a cylinder through the distribution valve. At the same time, the fluid ahead of it is
being displaced out of the meter through the outlet.
Four pistons in the cylinders are grouped in pairs and each pair is attached to a crankshaft
generating a rotation of the crankshaft.
Since the volume of the cylinder is known (0.125 liter) and the same amount of fluid passes
through the meter during each revolution, the exact volume of liquid passing through the flow
meter is known also. One full revolution is equivalent to a measured volume of 0.5 liter.
The rotary motion of the crankshaft is transferred outside the flow meter through the magnetic
coupling. The rotations are transferred through a pulse generator to an electronic register or
directly to a mechanical register.
The pistons are metal round discs covered with larger teflon gaskets. There is no metal-to-metal

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contact inside the cylinder. This prevents wear on moving parts, which means no internal leaks
and hence the accuracy remains consistent.
The crankshaft is fixed between a steel ball bearing at the bottom and a steel journal bearing at
the top. These bearings do not require lubrication and therefore no maintenance is required.
The magnetic coupling is an exclusive feature in the Yenen meter, which makes mechanical seals
redundant. The magnetic coupling connects the internal crankshaft through a unique design to the
shaft outside the meter.
Yenen carefully selected all the materials to suit the metering requirements and operational
conditions. All these features are designed to ensure long lasting and high accuracy as well as low
maintenance requirements and high dependability of the meter.
1.4 Documentation
Together with each meter you find an accuracy report. This is a Yenen report compiled during the
tests and calibration of the meter.
Each meter has a unique serial number to identify each meter. The serial number is related to a
date code: YYMM9999. For example a meter with serial number 01101234 is manufactured in
October 2001 with serial number 1234.
Record the meter serial number and model number as it will be required when calling for service
or spare parts.
2.0 Installation of the meter
This section is intended for LPG dispenser makers. It provides basic understanding of installing
Yenen flow meters in LPG measuring units. It is not all inclusive. Therefore operators of Yenen
LPG meters should both be trained and authorized by Yenen or should have prior dispenser
assembly experience.
Only trained and qualified personnel familiar with handling liquids under pressure, such as LPG,
may service Yenen equipment.
2.1 Meter specifications
Mechanical specifications:
Recommended flow rate:
6–60 liters per minute
Recommended temperature range:
-40ºC to +60ºC
Connection sizes:
Inlet: 1”Rp
Outlet: ¾” NPT
Pressure relief valve: ¼”NPT
Spare port: ¼” NPT
Pressure ratings:
Test pressure: 60 Bar
Design pressure:: 25 Bar
Working pressure:17.8 Bar
Water volume:
2.4 liters
Weight:
33 kg
Material specifications:
Main body
Nodular cast iron GGG35.3
Upper body
Nodular cast iron GGG35.3
Side cover
Nodular cast iron GGG35.3
Crankshaft
Nodular cast iron GGG50

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Piston arm
Nodular cast iron GGG50
O-rings
Nitril rubber NBR70
Piston gaskets
Teflon
Accuracy specifications (according to OIML R117):
Accuracy class:
1.0
Environmental class:
M2/E1
Liquid:
LPG, Butane, Propane
Accuracy:
Better than ± %0.5
Adjustment range:
+ and –0.5% in steps of 0.05%
Accuracy curve:
Flow rate –liters per minute
Pressure drop curve:
Flow rate –liters per minute
2.2 Installation requirements
Make sure that all internal pressure is relieved before installing or servicing LPG hydraulic
systems. See section 2.6.1.
When in doubt, contact Yenen for assistance.
Meters are calibrated with LPG and sealed before shipping. Removing a seal wire may require
recalibration. Check with the regulatory agency for further details.

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Make sure that all necessary safety precautions have been taken. Make sure that
ventilation, fire prevention, fire procedures and evacuation paths are provided.
Provide easy access to fire extinguishers. Understand and adapt all local safety codes.
Read this manual as well as other available literature and drawings.
See appendix A: DOs and DON’Ts
Install the meter and accessories in conformity with all applicable regulations and safety
codes.
During normal operation, observe the pressure ratings of the meter. Install pressure relief
valves to discharge any overpressure due to thermal expansion. Failure to observe this
may result in damage to the equipment and in serious personal injury.
The meter is packaged in a Volatile Corrosion Inhibitor (VCI) bag. The VCI bag prevents
corrosion, even in the presence of moisture. Naturally, it protects the outside of the meter
rather than the internal parts, but when kept on stock for a longer period the meter is
preserved much better.
Meter connections are protected with plastic caps. These should remain in place until
piping is attached. It is of vital importance for functionality and accuracy that dirt, dust and
other debris does not enter the meter. Ensure that the entire piping system is free from
dirt, dust and debris, as this may affect the functionality and accuracy of the meter as
well. Flush all material with a liquid, which is compatible with the meter before assembly.
Install filters in the hydraulic system and keep the work area clean.
Place the meter on a frame or platform with service in mind. Four M10 x 1.5 bolts should
be used to fasten the bottom of cover the meter to a frame. Do not hang the meter on
connecting piping. Make sure that the adjustment cover is easily accessible. It should not
be blocked by other components.
See appendix B for torque table.
Meters and measuring systems should be calibrated. The MID regulations state the
conditions of such calibration. Beware of local codes and regulations.
20-micronic filter (or better) should be placed before the meter inlet. The filter is a critical
part in preserving the meter accuracy –also see 2.4.
Water should not enter the meter as it may compromise the accuracy. Water and frozen
water may damage the meter. Water in the storage tank should be removed as much as
possible.
Minimize air and vaporization problems by following the manufacturer’s recommendations
in installing pumps.

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2.3 Meter dimensions
118.5 118.5
320
238
118.5153
INLET OUTLET
FOR RELIEF VALVE
FRONT VIEW
OUTLET (BOTTOM)
BOTTOM VIEW
Figure 2: Flowmeter General Dimensions

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2.4 Hydraulic part of LPG measuring systems
The hydraulic part of an LPG measuring system is a closed system. Unless permitted by (local)
regulations, there is no venting to the atmosphere. Overpressure in the system should be relieved
back to the vapor space of the supply tank through a vapor return line. Relief valves should be
installed in situations where gas can be trapped.
The vapor return line should not be connected to other return lines or by-pass lines.
The pressure line is connected from the pump to the dispenser inlet. Typically a 20-micronic filter (or
better) should be placed before the vapor eliminator. The filter is a critical part in preserving the meter
accuracy. Depending on the gas quality the filter should be replaced regularly. Especially in the first
month of operation the filter should be checked (and replaced) at least twice a month.
1. Nozzle
2. Break-away coupling
3. Differential valve
4. Meter
5. Pressure relief valve
6. Check valve
7. Check valve
8. Gas eliminator
9. Ball valve
10. Filter
11. Ball valve
12. Pressure gauge
Figure 3: Typical hydraulic set for 1-nozzle, 1-pump systems
The vapor eliminator separates vapor and LPG as only LPG should enter the metering unit. Back
check valves at the outlets of the vapor eliminator prevent re-entering of LPG. From a weights and
measures point of view this is especially important for the connection to the meter.
Systems with two or more nozzles (two single nozzle dispensers or double nozzle dispensers)
operating on a single supply line should avoid unregistered deliveries. In other words, with one nozzle
in operation, the other nozzle should not be able to deliver product. This can be prevented with a

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block valve.
2.5 Meter startup and operation
Make sure that all necessary safety precautions have been taken. Make sure that proper
ventilation, fire prevention, fire procedures and evacuation paths are provided.
Open the vapor line.
Check all connections with a soap solution for leaks.
Admit liquid slowly into the system by opening the ball valve of the supply line. As there
may still be some air or nitrogen in the system it is important to control the flow to prevent
damage to the meter. Make sure that the meter does not run faster than 25% of its rated
flow. Air or nitrogen should be eliminated gradually and carefully.
After air or nitrogen is removed and the system is full with LPG it can run within its
specified parameters.
Perform this sequence at first start up and after internal pressure has been relieved (also
see 2.6.1).
Most systems use an above ground or submersible pump. Make sure that the pump can operate
against closed valves or with limited flow.
2.6 Meter maintenance
Make sure that all internal pressure is relieved before disassembly or inspection of any part of the
hydraulic system. Failing to follow this instruction may lead to severe personal injury or property
damage.
ALWAYS disconnect and lock power supply before starting to service the meter and other
hydraulic parts.
2.6.1 Procedure for relieving internal pressure
Unless permitted by (local) regulations, relieving internal pressure should not be done to the
atmosphere. Check local regulations, standards and codes for the permitted procedure of
degassing LPG hydraulics.
This procedure describes purging the hydraulic system
with nitrogen:
Record the totalizer readings from the
dispenser in coordination with the station
manager.
Open the front and rear panel of the dispenser.
The rear panel should be opened as well to
ensure proper ventilation.
Remove the plug from the dispenser test port.
Connect the nozzle of the dispenser to the
maintenance port in the dispenser cabinet.