Metal Reinforced PE Spiral Corrugated Pipe and Accessories

Engineering Technique Manual

CHINALESSOGROUPHOLDINGSLIMITED

China Lesso Group Holdings Limited (Stock Name: China Lesso,Stock Code: 02128.HK) is a large industrial group of home furnishings and building materials in China. China Lesso’ s business porfolio spans plastic piping, building material and home furnishing, environmental protection, and supply-chain service platform. It offers products such as pipes, plumbing and sanitary ware, integral kitchen materials,integral doors and windows, aluminum alloy formwork and smart scaffolds, water purifiers, water-proofing materials and sealants, fire-fighting equipment, valves, cables, lighting, hygiene materials, items for environmental protection, agricultural facilities, and oceanic aquaculture cages.Its sales revenue has reached RMB 28.073 billion in 2020.

With the rapid development of internationalization and globalization,China Lesso boasts more than 30 advanced production bases distributed in18 provinces across China,and in some foreign countries.China Lesso remains committed to improving its strategic layout,broadening its sales network and expanding the market.This is how it provides products and services for customers in a timely and efficient way.

China Lesso has established its R&D center with more than 1,oo0 scientific researchers. The Group now possesses ten national high-tech enterprises, one national accredited enterprise technology center,two post-doctoral workstations,five China national accredited laboratories authorized by CNAS, one key enterprise laboratory of plastics molding and processing technology in Guangdong Province,and one union of Technical Innovation of PlasticPipe Industry in GuangdongProvince.

China Lesso owns about 2220 patents (some of them are pending). Some of Lesso’ s scientific achievements are included in National Torch Plan Projects, National Key New Product, Scientific Achievements Promotion Projects in National Construction Industry and Government Green Procurement List.The Group has been awarded many honorary titles and prizes, such as Champion Manufacturer, China Construction Independent Science Innovation Superior Enterprise, Intellectual Property Right Preponderant Enterprise,Industrialization Demonstration Base, Guangdong Provincial Government Quality Prize, and the First Prize of Scientific Technological Progress in Guangdong Province, and the First Prize of Scientific Technological Progress of China Light Industry Association.

As a domestic manufacturer of extensive home furnishings and building materials, China Lesso provides over 10,oo0 varieties of products with all specifications.Its products arebeing widelyused inmany areas,includinghomedecoration,civil construction,municipalwatersupply,drainage,powersupply and telecommunications, gas supply,fire-fighting, environmental protection, agriculture and oceanic aquaculture.

True to its mission of “Creating a Relaxing Life”, China Lesso will present a brand new image and offer more high cost-effective products and services to customerssothattheycanenjoyacomfortableandquality life.

JOINHANDS,FORGEAHEAD

China LESSO Group Holdings Limited (Stock Name: China LESSO, Stock Code: 02128.HK) astheglobal construcitonmaterialsindustrygroup coverspipeindustry,buildingmaterial and home furnishing industry,environmentalprotection Industry,channeland service and otherfields.

Contents

NewMetal Reinforced PESpiral CorrugatedPipe andAccessories ■Bell-and-Spigot Metal Reinforced PE Spiral Corrugated Pipe andAccessorieswithSealing Connection

Foreword 01

ENGINEERINGTECHNIQUE MANUALL

SectionI:

NewMetal Reinforced PE Spiral Corrugated Pipe
I.Product 02
I. Specifications.... 02
Ill.Product Performance 03
IV. Applications ...03
V.Pipeline Connection. 04-07

Illustration of commercial markincluded in pipes's and fittings' publicity materials:

LESSO Z LIANSU L&S

Bell-and-SpigotNewMetalReinforcedPESpiralCorrugated PipewithSealingConnection 08 I.Specification..... 09 Il.The advantage of new type sealingbell-and-spigot joint technology ..... ..9 Ill. Pipe connection. 10-12

All above trademarksareregistered trademarksof Guangdonglesso technologyIndustrial Co.,LTD. Please be informed that the products labeled those trademarks are products of lesso Group Company Limited.All rights reserved.

Section Il:

1. Pipeline Design 09
Il. Construction. 10-12

LESSO

Foreword

New Metal Reinforced PE Spiral Corrugated Pipe is a kind of structural wall plastic pipe formed by the melt compounding of PE and steel band. It is developed by reference to foreign advanced metal plastic pipe composite technology. The products implement the CJ/T225-2011 standard. The pipe structural wall consists of three layers. The high-density polyethylene is used as the primary structure, and the spiral-wound high-strength steel band is used as the reinforcement. And finally a unique manufacturing processis adopted to achieve the fusion of the steel band and the high-density polyethylene. Therefore, it has both the flexibility of plastic pipes and the rigidityofmetalpipes.

The water discharged into the pipeline complies with the current standard CJ343-2010 Wastewater Quality Standards for Discharge to Municipal Sewers, and the long-term temperature of the water transported does not exceed 45^\circC When the pipelinebeen buried in collapsible loess, expansive soil and permafrost, it shallcomply with the current national standards.

This manual is compiled on the basis of the current industry technical regulations and the suggestions of domestic municipal drainage experts, and is one of our company's product application and promotion materials. The design, construction and acceptance of the piping system shall also comply with the current national and local standards, norms or procedures.

Section I: New Metal Reinforced PE Spiral Corrugated Pipe

1. Product

1. High rigidity and strong resistance to external pressure

er is U-shaped steel band reinforcement, this product has an extremely hi

2. The pipe wall is firmly bonded

Each layer is firmly bonded. There is a transition layer between the steel band and the PE. The transition layer enhances the bonding ability of the PE and the steel band, and plays an important role as a barrier to oxygen and moisture to avoid the corrosion of steel band.

3.Easy construction, diverse connection methods, safe and reliable connection Light weight, easy construction and diverse connection methods, such as heat shrinkable tape (sleeve) connection, electrofusion connection, PE extrusion welding with a welding gun, etc., which can effectively ensure the connection strength.

4. Excellent wear resistance and good drainage ability

The interior of the product is smooth, the friction damping coefficient is low, and the surface roughness coefficient is 0.010. Compared withconcrete pipes of thesame inner diameter,thewater transferquantityisincreased by more than 40% underthesameconditions.

Il. Specifications

Note:The pipe length is generally 8m, other lengths upon request.Unit:mm

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Ill. Product Performance

Our company’s New Metal Reinforced PE Spiral Corrugated Pipe complies with the CJ/T225-2011 industrial standard of the MinistryofConstruction.Mainperformanceshown asfollows:

The ring-stiffness of the pipe should be selected according to external pressure load borne by the pipe.When the pipe is located under theroadway, itsring-stiffnessshould notbelessthan 8\mathsf{k N}/\mathsf{m}2 Underspecialcircumstances,thering-stiffnesscanbe designed and calculated according to the use conditions. This product is suitable for pipeline projects with a large buried depth.

IV. Applications

1. Municipal underground drainage and sewage pipelines.
2. Industrial drainage and sewage pipelines.
3.Seawaterand rainwater transfer pipelines.
4.Agricultural irrigation water pipelines.

V. Pipeline Connection

1. Pipeline sealing

Afterthepipeis cut,the exposed part of the steel band must receive preservativetreatmentwithPEmaterialof thesamematerialforthe laterpipeconnectionoperation.

2. Pipe cutting

\circleddash Cut the pipe only when required. ⊚ Thepreferred cutting tools shall include electric saw(Fig.1)and reciprocating saw (Fig. 2). The latter shall be used where steel band exists.

③ Wipethesurfacebeforecutting andremovethedebrisaftercutting.

\circledast Use the electric saw to cut in the helical direction, and try to keep the cutting line at the center line of the trough. Mark the cutting track with a marker when necessary to ensure a successful cutting. (Fig. 3)

\circled{5} If the cutting line is seriously deviated from the center line,cut the excess part again.Pipe connection is not allowed to be forcibly conducted to avoid the increaseof hidden dangers.

\circled{6} After cutting in a circle by following the above steps, cut off the pipe along the central axis. Do some trimming. (Fig. 4) \circled{7} After the cutting is completed, the burrs should be trimmed for the later pipe connection operation.

Note:Forpipeswiththesizerangeof 500~900, it is recommended to use theheat shrinkablebelt connection method;
extrusion welding is recommended when the pipe is temporarily cut at the construction site for reconnection.

2.HeatShrinkableBeltConnection

Steps: <br>\circleddash Adjust thetwo pipes tothe sameheight and maintain horizontal alignment before welding.Use crossers or sandbags tokeep thepipes at least 30cm awayfromtheground,orplace the pipe directly on the foundation if there is an operating pit.

⊚ Wipe the dirt,water and other debris at the connectionposition.

\circled{3} Preheattheconnectionpositionwithaweldingguntoremove the moisture on the surface of the pipe,and use a wire brush tomake theconnectionpositioncoarse.

\circledast Removetheplasticfilmfromtheinnerlayeroftheheat shrinkablebeltandcovertheheatshrinkablebelt onthe connectionposition.

\circled{5} Useawelding gun touniformlyheat theconnectionposition alongthecircumferenceofthepipetomaketheheat shrinkable belt shrink evenly and fully combine with the pipe.

3.ElectricFusionBeltConnection

To ensure a simplified and firm connection, the product shall be specially processed before the connection is conducted between thepipes.

Steps:

\circleddash Align the connection ends of the two pipes, and clean off the moisture and dirt.

\circled{3} Wrap the steel band on theelectricfusionbelt tomake its edgealignedwiththatoftheelectricfusionbelt.Connectthe drawvice tobothends of thesteel band and tighten it.

⊚ Wrapthenarrowelectricfusionbelt around thetroughof the connection position (requirement:the connection position shallbeinthemiddleofthetwoterminalsoftheelectric fusionbelt).

\circled{5} Use a PE extrusion welding gun to weld the connection positionsinside,outside and inthe periphery of thepipe (there is no need to weld the inner connection position for small-sized pipes).

\circledast Connect the clamp of the output end of the electric melting weldertotheterminalsoftheelectricfusionbelt.Thensetthe weldingparametersaccordingtotheworkingtemperature and the pipe diameter, and turn on the power for heating. Aftertheheating,turnoff thepower and removethe clamps, and tighten the steel band again.

\circled{6} After cooling for 30 minutes,remove the steel band,and thewelding is completed.

LESSO

4. Extrusion Welding

\circleddash Thehotairtemperatureof theweldershouldberaised toabout 350 ± 15 °C. Thehot airtemperatureismainly determined according to thewall thickness of the pipe tobe welded and the ambienttemperature.Ifthewallthicknessislargerandthe ambienttemperatureislower,itshouldberaisedtoahigh temperature.Otherwise,a low temperature should be adopted.

⊚ The extrusion-melt temperature should beraised to about ^{230±} 10 °\mathsf{C} for test welding.Drain the flash at the nozzle before each welding,and then extrude the melt material from the welding gun to conduct welding.

\circled{3} In the initial welding, preheating should be conducted by using the hot air.Thepreheating time should bedetermined according to the wall thickness of the pipe.Afterthe preheating,extrude the melt materialto conduct welding.During thewelding process,the welding gun nozzle should squarely facethe weld seam to ensure that the extruded melt material is squeezed into the weld seam, andslowlymovetheweldinggunalongthepreheatedareato gradually fill thewelding seam.At the same time,and an external forceisapplied tocompactthemeltmaterialextrudedintothe seam,and thentheentire circumferenceiswelded.

\circledast For large-diameter pipes(aboveId800),the seams inside and outside of theconnectionpositionshould bewelded asmuchas possible to ensure sufficient strength.If it islimited by the field environmental condition,the welding quality of the seams on the inner surface of thepipe should be ensured.

\circled{5} Do not move the connectionpositionimmediately afterthe welding until the pipe naturally cools to room temperature,and forced cooling is not allowed.

\circled{6} Aftercooling,the welding quality must bechecked topreventfalse solder and solder skips.If any of the above occurs,repair welding mustbe conducted.Beforethat,the surface of the area where weld defects exist should be cleaned byremoving theforeign matters suchasanoxidelayer.

Bell-and-spigot Steel band reinforced polyethylene (PE) corrugated pipe with sealing connection

II. The advantage of new type sealing bell-and-spigot joint technology

1. The installation mode is simple and quick. Only tensioner and lubricants are required for construction.
2.The construction condition is simple without dependence on power supply and motor fuse,enabling flexible construction.
3. The construction cost is low with high installtion efficiency.
4.The internal sealing ring adopts multiple-step structure for sealing to ensure to pass the closed water test and deflection angle test.
5.LESso is the only company with such mature installation company at present.

Ⅲ.Pipe connection

The new type steel band reinforced polyethylene (PE) spiral corrugated pipe with bell-and-spigot joint adopts elastic sealing ring bell-andspigotjoint with the connection and installation steps asfollows:

Considerations for connection

The position of rubber ring should be placed inside the fixed neck at the spigot end.

1.In thepipe,thespigot shouldgo along with thewaterflowdirection and thebellis against waterflowdirectionforinstallation.he installation should be conducted from downstream to upstream.
2.The pipemaybe put in place with useof tensioner or chainhoist.Whenthejoints gatherup,the chainhoist at two sides of the pipe should be pulled at the same time to make the rubber sealing ring at right place without distortion and falling off.
3.The measures to stabilize the pipes should be taken to prevent movement of axis position of pipes that are laid when the joints gatherup. The wovenbagsmay befilled withsandy earth andpress against the laid pipes.Orbackfill isconducted to 30cm abovethepipetop according to standard requirement directly only with the joint exposed to facilitate inspection of closed watertest.The installed pipes will not movein thisway.
4. After installation of pipe joint is completed, the pipe elevation and axis should be rechecked to make it meet the design requirements.

Section Il

1. Pipeline Design

Basic design rules

1.Theservicelifeof the product should not belessthan 50 years. 2. The design loads of the pipe should include the vertical soil pressure (WC), the vehicle load (Fc) on the ground, and the heaped load (Fs).The vehicle load and the heaped load are not calculated in a superimposed manner, whicheverislarger.Thevehicleloadshouldbecalculated accordingtothe actualsituation.

Hydraulic calculation

The velocity in pipe shallbe calculated according to the Manning formula:

V=R%1 n

Structure calculation

1.Vertical deformation calculation

1.1 When buried plastic drainage pipes are subjected to the externalpressureload,thevertical diameterdeformationrate shouldnotbemorethan 5% oftheallowabledeformation rateofthepipe diameter.Thediameterdeformationrate and the allowable diameterdeformationrate shallbe calculated by thefollowingformula:

In formula:E verticaldiameterdeformationrateofpipe, \varepsilon<=5% \mathsf{W}_{d, max}- maximumvertical diameter deformationof the pipe under the combined load (\mathsf{mm}); {\mathsf d}_{\mathsf{i}}- pipe inner diameter(mm).

1.2 The vertical diameter deformation of the pipe under the combined load can be calculated by the following formula:

In formula: Wd,max — maximum vertical diameter deformation of the pipe underthecombined action (mm)

DL一 Theverticaldeformationlagcoefficient of thepipeline canbe taken as 1.2-1.5 according to the compaction degree of the backfill in the thoracic cavity of thepipeline;
Kd —— pipe deformation coeficient, determined according to the tablebelow;
qsv,k—standard value of vertical soilpressure per unit area at the top of the pipe (kN/m2);

In formula:Q - flow quantity (\mathsf{m}^{3}/\mathsf{s})

A—waterflow effective sectional area (\mathsf{m}^{2})
v—flowvelocity (\mathsf{m}/\mathsf{s})
n—pipe roughness coefficient (accurate to 0.010); R—hydraulic radius (m）;
I —hydraulic gradient.

Designvelocity should complywith the national standard<Code forDesignofOutdoorWastewaterEngineering > Themaximum design velocity of thepipeline should not exceed 5m/s The minimum designvelocity shouldmeetthefollowingrequirements: for sewage pipes at the design fullness,it should be 0.6\mathsf{m}/\mathsf{s}, andfor rainwaterandconfluencepipesinfull flow,it shouldbe 0.75m/s

qvk——standard value of vertical pressure transferred from ground vehicleload or heaped load toperunit area at the top of the pipe ({\mathsf{k N}}/{\mathsf{m}}2)
Wq quasi-permanentcoefficient of variableload, accurate to 0.5;
Sp nominal ring stiffness of the pipe (kN/m2);
Ed- overall deformation modulus of lateral soil (kN/mm2).
D1——-pipe outer diameter (mm)

1.3 The overall deformation modulus of lateral soil can be determinedaccordingtorelevantstandards.

2.Anti-floating stability calculation

2.1 The safety coefficient of the anti-floating stability of the pipe should not beless than 1.10.
2.2 The calculation of anti-floating stability shall comply with the followingrequirements:

Informula: \sum F_{G k} — the sum of charactersic valueso permanent ction of anti-floating; F_{f w,k} standard value o buoyancy force; K_{f} coefficient of stability of floatation resistance of the pipe, accurate to 1.10.

3.The strength calculation of the pipe ring section under the external pressure load shall be conducted according to relevantregulations.

LESSO

Il. Construction

General

1.Pipes shouldbe laid on natural soil foundation orbackfilled foundation.If the pipeline is under the roadway,the thickness of the covering soil at the top of the pipe should not be less than 0.7\mathsf{m}
2. The pipeline should be laid in a straight line.In case of special circumstances, a small angle is allowed at the joint,but it should notbegreaterthan 2°
3. When Metal Reinforced PE Spiral Corrugated Pipe pass through obstacles like railways,high-grade road embankments and structures,protectivesleevesmade ofreinforced concrete,steel, castiron,etc.shallbe used.The inner diameter of the sleeve shall be greaterthan the outer diameter of the corrugated pipe by300 mm.Thedesignofsleeveshallbeconductedinaccordancewith therelevantprovisionsof the embankment.
4.Metal ReinforcedPE Spiral Corrugated Pipe shall not pass through under the foundation of a building or structures.
5.Technical requirements for measurement,precipitation, grooving, trench support and pipeline cross processing in the construction shallcomply withthe current national standards and thelocal technical regulations for drainage pipeline.

Trench

1. The net width of the trench bottom can be determined according to the specific conditions of each region.
2.Duringthe trenchexcavation,theelevationof thebaseshallbe strictly controlled without disturbing thenatural soil.The natural Soil 0.2~0.3m abovethedesignelevationofthebaseshallbe cleanedtothedesignelevationbeforeartificialexcavationand pipelaying.Incase of partial over-excavation or disturbance,it shall not bebackfilled with soil.Naturally graded sand-gravel or gravels with a maximum grain diameter of less than 40\mathsf{mm} can be used forbackfilling and compaction.Hard objects at the bottomofthetrenchmustberemovedifany,andsand-gravels shall be used forbackfill treatment.
3.During therainyseason,thelength of thetrench should be shortened as much aspossible,and finish the trenchexcavation and backfilling as quickly as possible, and take measures to prevent the trench from long-time immersion.
4.For artificial trench excavation,the mixed soil in the upper part of thetrenchshouldbestackedseparatelyfromthegoodsoilinthe lowerpart,the lattercanbeusedforbackfilling,and the stacked soil should not affect the stability of the trench.

Construction drainage

1. In areas where thegroundwater level ishigher than thebottom elevationofthetrench,measuresshouldbetakentolowerthe groundwaterlevel during construction to prevent trench instabilityafterexcavation. 2.The method of lowering the groundwaterlevel shallbeselected according to the soil penetrability and precipitation depthin the area, and the conditions of construction equipment. 3.The groundwaterlevel should be _{0.5m} lowerthanthebottomof thetrench.Nowatershouldbeaccumulated inthetrench. Constructionisstrictlyforbiddeninwater.

4.If the construction adjacent to buildings, preventive measures should be taken to prevent the buildings from being affected. 5.Afterthe pipeline is laid,thelowering of groundwater level should not be stopped during backfilling until the trench is stablyconsolidated.

Foundation

1. The pipeline foundation shall be soil arc foundation.For sections ofgeneralsoiltexture，a 1 0.1 \mathsf{m} -thickcoarsesand layershallbe laid on the natural soil foundation or the backfilled foundation; for soft foundation, and if the groove bottom is below the groundwater level, a gravel base with a thickness of no less than 0.2\mathsf{m} shall be laid, the gravel base can alsobe divided into two layers. The lower layer uses gravels with a particle size of 5~32\mathsf{mm} and thethicknessis 0.1~0.5m Theupperlayeruses coarsesand and thethicknessshallnotbelessthan 0.05\mathsf{m} The compactness of the foundation should comply with this manual. If the foundation capacity is lower than the design requirements or due to construction precipitation and other reasons, the naturalsoilof thefoundationisdisturbedand affectsthe bearing capacity of thefoundation,it must firstconduct reinforcementtreatmentforthefoundation.Afteritreachesthe specified foundation bearing capacity,the medium coarse sand basecanbelaid.
2. At the haunches within the design soil arc foundation support angle, it must bebackfilled withmedium coarse sand or gravels. The backfill density should be in accordance with this manual.
3.Forthesectionswhereunevenlongitudinalsettlementofthe pipeline may occur due to factors such as pipeline load and soil changes,thereinforcementshouldbeconductedforthe foundationbeforethepipelineislaid.

Pipe installation

1. Pipe installation can be manually conducted.If the groove depth is not large,pipes can be manually transported into the groove.If the groove depth is greater than 3m orthe pipe diameteris largerthanthenominaldiameter \mathsf{D N400mm} non-metallicropes can be used to slide the pipes into the groove,and then steadily place the pipes in position one by one on the gravel foundation. It is forbidden to use metal ropes to hook the two ends of the pipe and then let it rollinto the groove.For mixing or supporting grooves,thepipes canbe intensively laid down at the one end of the groove, and then transported in place at the bottom of the groove.
2.During the rainy season,measures should be taken to prevent pipes floating. Backfilling can be conducted to a height which is morethanonepipediameterawayfromthetopofthepipe.If pipe installation has been completed but backfilling has not and thepipesaresubjected tobeingimmersed,repetition measurement and visual inspection of the center line and the bottom elevation of the pipe should be conducted.If there is any displacement orfloating,reworkshouldbeconducted astimely aspossible.
3.Pipe connection methods include heat shrinkable belt connection,electric fusion connection and extrusion welding.

LESSO

Backfilling

1. General

1.1Backfilling should be conducted immediately after pipeline installation passes the acceptance test.Before the impermeabilitytest,exceptforthejointsthatcanbeexposed, the backfill height at the two sides and on the top of the pipe shouldnotbelessthan 0.5\mathsf{m}; afterthetestissuccessfully passed, the rest parts should be backfilled in time.

1.2 Trench backfilling should be carried out symmetrically at both sides of thepipeline,inspection chambers and other structures to ensure that thepipelines and thestructures donothave lateral displacement.Temporary limit measures should be taken when necessary toprevent lifting.

1.3Fromthe bottombase to _{0.5m} above thetop of thepipe, backfillingmustbe conducted manually.It is strictlyforbidden to use mechanical bulldozing backfilling.

1.4 Beyond the above-mentioned range, backfilling can be conducted simultaneously from both sides of the pipe axis by mechanical means.

1.5Thereshould benowateraccumulated in the trench during backfilling, the backfill should not include sludge, organic matter and frozen soil,and there should beno stones,bricks and other hard objects in the backfill.

1.6 If steel sheet piles are used to support the trench,they can be removedafterthebackfillingreachesthespecifiedheight.After thesteelsheetpilesareremoved,thepileholesshouldbe backfilled intime,and measuresshouldbetakentohavethem fully filled.If sand filling is adopted, it can be compacted by flushing.If there arerequirementsfor controlling land subsidence, it is advisable to take the measures of simultaneously conducting grouting and pile pulling.

1.7 Pipe vertical deformation should be strictly controlled during backfilling.If the pipe diameter is large and the covering soil on the top of the pipe is high, measures like temporary support or pre-deformation can be taken inside the pipe. During backfilling, the reverse vertical deformation occurring in the backfill compactionprocessinthepipe chamber canbeused to offset the pipe vertical deformation caused by part of the vertical load, but it must be controlled within the designed pipe vertical deformationrange.

2. Backfill materials and requirements

2.1 From the pipe bottom to 0.5\mathsf{m} above the top of the pipe,the trench backfill materials and the compactness shall comply with thetablebelow.
2.2 Thebase layer at thebottom of thepipemust belaid on the foundation that meets the bearing capacity requirements.
2.3Within the central angle 2α of soil arcfoundation,thehaunches underpipemustbefilled andcompactedwithmediumorcoarse sand and tightly contacted with the pipe wall. Soil or other materialsshall notbeused.
2.4 Pipes should be symmetrically backfilled and compacted layer by layer. The backfill height of each layer should be no more than 0.2\mathsf{m} Withintherangefromthetopofthepipeto 0.4\mathsf{m} above it, it is not suitable to use mechanical compaction.
2.5 The backfill compactness should meet the design requirements. Whenthereisnodesignrequirement,it shouldmeetthe requirementsspecifiedinthetableandfigurebelow.

Pipeline impermeability test

1. After the pipeline installation and acceptance,impermeability test shallbeconducted. 2. The impermeability test shall be conducted after the haunches underpipearebackfilled andcompactedwithsand.When necessary,it can be conducted underthe condition that the distance between the pipe top and the backfilling height is as high as the pipe diameter (the pipe joint is exposed). 3.During the closed water test,the pipe should be filled with water and the2mhead pressure above thepipeat the upstream should be maintained.After visual inspection,there shall be no water leakage. The 24h water seepage quantity of the pipeline should be in accordwith theresults calculated bythefollowing formula:

Q≤0.0046d;

Where:

Q- 24h allowable water seepage quantity per 1km (m3); di-pipeinnerdiameter(mm)

Pipe repair:

1. During the installation process, if the pipe wall is partially damagedaccidentallyandthediameterofthedamagedpartis notmorethan 60\mathsf{mm} orthecircumferentialcrackdoesnot exceed 1/12 of the pipe circumference,then PE sheet of the same material can be used for hot melting repair.
2.If the extent of damage exceeds the above scope or the pipe body is damaged, then the whole damaged pipe section shall be cut off and replaced by another pipe section of the same length, or takemeasuressuch asbuildinginspection chambers and connectingchambers.
3.If thePE anti-corrosion layer on the outer surface of the pipe is damaged,thedamaged area should bepolished and cleaned. First apply the melt adhesive on the surface of the steel band,and then adopt extrusion welding oruse PEsheets of the same material for hot-melt repair.
4.After the damaged pipe is cut off, the fracture position of the steelband at thepeakshould receive extrusionwelding,oruse PE sheets of the same material for sealing and anti-corrosive treatment.

LESSO

CHINALESSOGROUPHOLDINGSLIMITED

(Hong Kong Listed Stock Code: 2128)

GUANGDONGLIANSU TECHNOLOGYINDUSTRIAL CO.,LTD.

Production Base:

LIANSU Industrial Estate, Longjiang Town, Shunde District,Foshan City, GuangdongProvince528318,China

Sales Tel: (86) 757 23379211 Fax:(86) 757 23378980 E-mail: oversea@lesso.com Asia-1 : (86) 757-29223015 Africa-1: (86) 757-29226356 Middle East :(86) 757-29226355 Asia-2:(86) 757-29220500 Africa-2 : (86) 757-23379211 South America:(86) 757-29220501 \* This catalog has been prepared as a support guide. Under no circumstance shall LESSO assume any liability or responsibility with the information in this catalog.Every effort has been made by LESSO to provide accurate and up to date information.

All Rights Reserved 2021.06 Printed in China (HC)