Thin-Walled Stainless Steel Pipeline

Installation Instruction

(Version: 02)

ADD：No.678, Dingxiagn Road, Binhai Garden, Wenzhou, Zhejiang.

TEL:：+86-577-86852999

FAX:  +86-577-86909188

PREFACE

This book is based on standard “Stainless Steel Press Fittings GB/T 19228.1”, “Stainless Steel Tubes for Connecting Press Fittings GB/T 19228.2”, “O-ring Seals for Press Fittings GB/T 19228.3”, “Code for Design Building Water Supply and Drainage GB50015-2003”,“Building Water and Heating Engineering Facilities Quality Acceptance GB50242-2002”, “Welded Stainless Steel Pipes for Liquid Delivery GB/T 12771-2000”, “Light Gauge Stainless Steel Water Pipes CJ/T 151-2001”, “Metallic Pipeline Installation of building water supply 04S407-2”, and “Technical specification for light gauge stainless steel pipeline engineering of building water supply CECS153：200”. It is edited after taking advice from competent department and user of related design, develop, material, construction, and doing a lot tests and pilot project, meanwhile combining recent national product standards, and then concluding the properties of stainless steel press pipeline. The aim of the book is to make the construction installation easy and quick, and avoid leakage.

I. Basic principle

The basic components of stainless steel press fittings are made of pipe joints with o-ring sealing in the “U” type groove bead. When assembling, insert stainless steel pipes into pipe fittings, and press by special tools to make the joints of pipes and fittings to be hexagon, so that forming strong connecting tensile strength on the o-rings to deform and so sealing tightly.

II. The application and properties of stainless steel connection

1.         Application

The stainless steel press connection is suitable for fluid transportation with working pressure max 1.6MPa, widely used in fluid transportation stainless steel pipeline of drinking water, life portable water, cold water, hot water, sea water, gas, fire fight, industry, medical gas and so on.  

2.         Properties

a)                                                Hygienic and anti- corrosive

Stainless steel pipe is a kind of recognized environmental healthy material. Its service life is more than 50years, satisfying the drinking water standards’ requirements of china, Japan, Europe and other countries.

b)                                               Fast installation

The stainless steel fittings can be suitable for severe environment. No threading, no welding, and

only cost one-quarter time than that of galvanized iron pipe fittings; the installation of press fittings is very flexible, no matter how  small the piping shaft is or in leaking trench, not only reducing the project time, but also the installation cost. 

c)                                                Shock resistance and thermo conductivity

The tensile strength of stainless steel pipes is two times than that of GI pipes, three times of that of copper pipes. Its thermo conductivity is one twenty-fifth of copper pipes, one quarter of steel pipes, featured with slow thermal expansion and contraction.

d)                                              Saving material

Because of being thin-walled, the pipe weights only one third of galvanized iron pipe, saving material a lot, reducing product weight, especially suitable for rather high building piping.

e)                                                The product appearance is beautiful: let alone new installation or long using, it can match with new decoration environment.  The inside of the joint wall is smooth and so little water resistance.

III. Technical reference

1.            Material: austenitic stainless steel 06Cr19Ni10(S30408) is commonly used； and austenitic

stainless steel 06Cr17Ni12Mo2(S31608) and 022Cr17Ni12Mo2(S31603 ) are used to high requirements to corrosion. 

2.  Sealing: O-ring sealing commonly use EPDM rubber, no poison, no smell, total hygienic, high temperature resistant(-20℃～110℃), hot water resistance, anti-aging, anti additive and so on, suitable for drinking water, the best used sealing material.  

3.  Nominal diameter:DN15～50mm. The details refer to the pipe parameter-table 3.3-1.

4.  Working pressure: max 1.6Mpa.

5.  Working temperature: -20～110℃ .

6.  Connecting way: press.

Table3.6-1  material parameter table（mm）

IV. Material selection

    The performance of thin-walled stainless steel pipes： beautiful appearance, high anti-corrosive, high mechanical strength, strong anti-vibration, no harmful material in transportation, promising no deterioration of water quality in transportation, and recyclable as environmental material.       

1.  Material size

2.  Transportation and storage

2.1 When moving pipes and fitting, handle with care and avoid contamination. Violent crash, push, throw, roll and drag are strictly prohibited.   

2.2 Fittings shall be stocked inside room. Outdoor stock is not allowed.

2.3 Pipes shall be put on smooth floor or horizontal bracket. The overhang end on bracket shall be not over 0.5mm, the height shall be lower than 1.5m and only less or equal to 5 cartons of fittings can be put in one stack.

2.4 Avoid operating forcibly in case of deformation of pipes and fittings. When transporting pipes, no heavily press, hit, crash, throw, bend and other avtivities to make pipe deform or crack.

2.5. No touch of oil stain.

V. Tools

1.  Tools：Cutting knife (machine), jaw, clamp, manual hydraulic press tool, electricity hydraulic press tool, big size clamp, hexagon gauge and so on  

cutting knife (machine)：It is recommended to use cutting knife for small size pipes for house

construction, and to use alloy steel cutting machine for projects to cut small and big size pipes to

improve the construction efficiency and meanwhile make the pipe mouth vertical and smooth.  

cutting knife     electricity hydraulic press tool     manual hydraulic press tool

jaw                     hexagon gauge 

jaw：the tool to make the fixed shape when pressing the joints 

clamp： the tool used to connect the jaw and the press tool

manual hydraulic press tool：the tool is to press pipes and fittings manually.  

electricity hydraulic press tool：the tool to press pipes and fittings electrically. 

hexagon gauge： the tool used to test if the press is ok, if the hexagon gauge cannot totally click into the pressing joint, then the pressing is not qualified, otherwise, it is qualified.

VI. Installation

1.          Installation process

①choose the right size pipe→②cut as needed→③deburr→④marking→⑤insert into fitting mouth→⑥pressing→⑦test

2.          Detailed installation process

2.1 Choose the pipe

According to the real need of pipeline, to choose the right material and size, and calculate the needed length of the pipe. 

The choose of thin-walled stainless steel pipes shall accord with the application and transportation medium according to the regulation of table 6.2.1－1and table 6.2.1－2. 

Table 6.2.1－1 material grade and application of 300 series stainless steel pipes and fittings

Table 6.2.1－2 material grade and application of 400 series stainless steel pipes and fittings

2.2 Cut the pipe to size

The cutting of stainless steel pipes shall adopt the cutting way of no obvious     

temperature increasing. The cutting way that may bring high temperature         

such like abrasive-disk cutter. To cut pipe as the length need for installation

by using right handsaw or a mechanical saw. If the pipe end deforms after

cutting, we should use shaping tools to make the pipe end circle to make

sure pipe mouth equally round.   

Notes：No matter to use handsaw or a mechanical saw to cut pipes, the   man must pay attention to make the incision and pipe in vertical level.   See the allowable tolerance of pipe end chamfer to table 6.2.2－1.                             Picture 6.2.2 deviation of pipe cutting chamfer     

Table6.2.2－1  the allowable tolerance of pipe end chamfer (mm)

2.3 Deburr the pipe

To remove the burrs of the pipe ends is to avoid damage to the o-ring when      

inserting the pipe into the press fitting.     

2.4 Mark insertion depth

Marking pipe end by marker pen shows the length to insert. See the basic length    

to table 6.2.4－1， to avoid leakage because of short insertion

Table 6.2.4－1  Basic values of pipe insertion length（mm）

2.5 Inserting pipe mouthing

Check the o-ring to make sure it is in right place of the fitting bead, and insert the pipe into the press fittings up to the marked insertion depth and pushing in an axial direction at the same time. Rough and careless insertion of the tube into the press fittings may result in damage to the O-ring and is therefore not permitted. The marking for the insertion depth must still be visible, and make sure the distance between the marking place and pipe end is about 3mm for fitting size 15-25mm, and 5mm for fitting size same or bigger than 32mm.  

2.6 Pressing connection

a)                           Put the groove of press jaw enclose tightly on the fitting bead, put the tool jaw and pipe in    axial direction and then operate pressing.   

Both manual and electricity press tools are suitable. Before starting to press, the jaw and tool itself must assemble in good condition. When pressing is finished, there will be one sound “bang” after starting pressing for some seconds; When using manual press tool, each pump motor should be the max stroke and the return valve is in close;  press slowly to make the jaw close tightly, and then release pressure after the pressure is steady for 3-5seconds till the pressing process is finished. After pressing, the last process is to use hexagon gauge to test if the pressing is good or not.   

b)                          If the pressing is not in place, to press again by rotating press tool 60°, and test again by        hexagon gauge.

Notes: when connecting with female or male thread adapters, threads should be screwed tightly before press. 

To use different jaw follows the installation instruction, and lock or unlock all fixed bolts and pins in case to damage the tool.

2.7 Test

Test the pressing joint by special hexagon gauge. And test pressure after    

whole pipeline installation. 

VII. Test and inspection method

1.            The water pressure of pipeline system shall accord with the following specification：

a)                The test pressure shall be 1.5times of the pipeline system, but no more than 0.6MPa in building water supply;

b)               The pipeline system shall be fixed and protected safely before water pressure test, but

the pressing joints must be visible. 

It is suggested to test step by step in pipeline pressure test, from branch pipeline to whole system.  

Water pressure test steps：

a)                Plug the pipeline ends and fill in water slowly to exhaust all air out. It is suggested to set air outlet in every branch of pipeline system. 

b)               Test water tightness inspection after filling in water.  

c)                Adopt manual pump to increase the pressure, with increasing pressure time more than10minutes.

d)              Stop increasing pressure till a fixed value and keep pressure for 1 hour, then observe if there is leakage in joints. 

e)                After 1 hour, replenish the pressure to the fixed value. The decreasing pressure in 10min should be no more than 0.02MPa.

f)                 When there is leakage or pressure is over than fixed value, pipeline system should be checked first. And only the above questions are solved can we start to test pressure again till to satisfy the requirements.

2.            The measuring range of pressure gauges for pipeline pressure test machines should be 3times of

3.            test pressure, and checked qualified in validity period, with scale division 0.05MPa. 

4.            Before to use the water supply pipeline, we should use clean water with 20mg-30mg free chlorine each liter to disinfect. The water with chlorine shall keep still more than 24h in pipeline. After disinfection, to wash the pipeline with drinking water. And only when test qualified by hygiene department according to the national standard “Life drinking water standard”, can the pipeline system be used.       

VIII. Construction technical requirements

1.                Connecting with other pipes and valves

a)                To avoid electrochemical corrosion, electric insulating treatment shall be done or not when connecting stainless steel and other material, see to table 8.1-1.

Table8.1-1 Insulating treatment table

b)              Connection way

u  Pipeline system of nominal diameter 15mm-32mm shall be connected with other pipes by pipe threads (thread sealing).

u  Pipeline system of nominal diameter 40mm-50mm shall be connected with other pipes by pipe threads (thread sealing) and PN1.6 flange.

u  Pipeline system of nominal diameter bigger or equal to 65mm shall be connected with other pipes by PN1.6 flange.

u  When connecting by thread fittings, enough PITE tape or hemp thread shall be used; when connecting by flange, flange face sealing shall be used.

2.          The shortest distance between joints – see toTable8.2-1

Table8.2-1  Shortest distance table between joints（mm）

3.          Piping rack

3.1 The support interval between stainless steel vertical pipe and horizontal pipe shall accords with the specification of table 8.3-1.

Table 8. -1  The biggest support interval of pipe clamp（mm）

3.2 The way to fix clamps：The material of clamps can be plastic, china and other nonmetal material, such like the metal clamp must be same as pipe material. In moist condition, if different metals connect together in long term, it will result electrochemical corrosion, and rust pipe clamps, which will simply affect the aspect, or risky punch a hole in the pipe in long-term corrosion.    

4.          Concealed installation of pipes

4.1   When adopting cement plaster to fill in concealed installation pipeline, surround material shall be used to keep gap between the cement plaster and pipes so that the concealed pipes can move elastically. 

4.2   Indoor concealed installation： when the pipeline penetrates into wall, floor as concealed installation, holes or grooves shall be reserved to match with build project to make sure the safety and convenience of installation. The reserved hole or groove shall accords with the following requirements: the hole size shall be 50-100mm bigger than the pipe outside diameter; the groove in wall shall be 20mm deeper than pipe outside diameter, 40-50mm wider than pipe outside diameter, and no less than 100mm of the room overhead line fair tube.

The pipeline shall be levelly or vertically put on the reserved or opened grooves, fixed by clamps, and filled in grooves by cement plaster after pressure test for one week. 

The net distance between life water supply pipeline and drainage pipeline concealed in building floor is: no less than 500mm for level concealing, no less than 150mm for cross concealing, and the water supply pipes to be overhead the drainage pipes. 

4.3   Outdoor concealed installation

The installation of stainless steel press pipeline system under terrace ±0.00 is fit into two stages. First concealing installing from under the terrace ±0.00 to outside of basic wall; second, installing the outdoor pipes after finishing building project.     

The indoor terrace pipeline installation must restart to dig after the building project is tamped by filling in earth. No installation in terrace is allowed before filled in or tamped. In outdoor terrace, firm stand must be fixed in pipe grooves, and firmly supported in the distance ≤100mm from the fittings.

The groove to install pipeline must be smooth, no bulging hard thins, or laid with sand mat if 12mm up to 300mm over the level pipes. There should be no hard things mixed with the soil when filling back. And only after tamped can fill back with the original soil. The indoor concealing pipeline depth shall not smaller than 300mm. The earth covering depth of outdoor water supply pipeline shall be decided by the soil frost depth, car load and pipeline cross, etc. The min earth covering up pipes shall be not smaller than 150mm under the earth frost line. 

The piping under roadway：

a)          nominal diameter ≤200mm covering earth depth shall be not smaller than 1000mm；

b)         nominal diameter 20-400mm covering earth depth shall be not smaller than 1500mm；

c)          nominal diameter ≥450mm covering earth depth shall be not smaller than 2000mm.

If the stainless steel press pipeline will cross the road with the covering earth thickness less than 1000mm, serious protection measures shall be taken. 

When concealing the pipeline, marks shall be made to avoid nails or drills to break.

5.          Line compensation

5.1   When the straight length of pipes exceeds 15m, there shall be line compensation.  The deformation value will be：

△L=L×α×t­ 1- t­ 2＝L×α△×t

In the formula：△L――deformation value，mm；

      L――the pipe length, m;

      a――coefficient of linear expansion, mm/m·℃, stainless steel is 0.0166；

△t――temperature difference，℃.  t­ 1：the highest temperature in pipeline fluid， t­ 2：the environment temperature around the pipeline， normally t­ 2＝5℃；

5.2 Compensation method

   The thermal expansion of pipe can adopt natural bending compensation and compensator compensation.  

a)                Pipes ≤DN32 will be possibly fit to use natural bending compensation, such like bending, U type or Z type and other compensation methods. 

          Bending                     U type                     Z type 

b)  Pipes ≥DN32 will be suitable to adopt compensator compensation, such as bellows compensator, lapped joints compensator, packing type compensator and so on. 

It is suggested to use bellow compensator for the axial or radial place caused by expansion and contraction in water supply pipeline system. The bellow stroke value will be calculated by the pipe length in fixed pipeline support and the compensator theory, considering its bending deformation, fatigue life and safety factor to calculate the bellow numbers. 

5.3 When horizontal main-pipe connects with horizontal branch-pipe of hot water and vertical pipe connects with hot water branch-pipe of every floor, measures shall be taken to make the pipe expansion is not affected with each other.    

6.          To keep warm and freeze frostbite of pipeline

6.1                 Keeping warm

The material to keep warm may choose the material without leachable chloride, such like foam HDPE, rubber, mineral wool, perlite and other thermal insulation material. But pay attention different environment requires different according to working condition and temperature.

Notes：

a)                Don’t let water entering the inside of thermal insulation, if necessary, adding waterproof layer outside the thermal insulation;

b)               Don’t leave room between the thermal insulation material and pipes by fixing with adhesive tape.

c)                Choose the thermal insulation material thickness according to the local thermal construction standard.

6.2                 Anti-freezing

If the piping is anti-freezing, there will something wrong in the fitting. So to exhaust all water in pipe totally or to add thick thermal insulating material where will possibly freeze. Pay attention to the following points:    

a)                Make sure the lowest temperature in this area in winter, and set up anti-freezing temperature to ensure thermal insulating material and thickness;  

b)               There should be no gap between thermal insulating material binding surface and fittings, to do better the insulating work;   

c)                In windward or shady places, add thicker thermal insulating material with piping; 

d)              In cold area, it is not suitable to choose small size pipes and fittings; 

e)                In cold area, non-freezing plug and drainage plug must be set up, rolling with anti-freezing resistance wire “R”.  

Notes: Carry out the anti-freezing measures according to design requirements in different places.   

7.          Pipeline maintenance

When changing or maintaining pipelines, only need to cut the pipeline needed, and to change or maintain the pipeline according to the above installation instruction.  

8.          Other cautions

a)                     The indoor water supply pipeline is not suitable to go through any distributing substation, elevator machine room, communication machine room, big-and-middle-sized computer room, computer net room, image database and other places will go bad or cause accidents when comes across water, or put on any of the above production equipments.    

b)                    The water supply pipeline should not go across dilatation joint, settlement joint and movement joint. If it must go across, compensation pipeline dilatation joint shall be set up or cut the deforming device.   

c)                     To make familiar with water supplying diagram, and check if the model and sizes of the pipes and fittings will reach the requirements. Don’t tear down the packages or pipe end caps before approval.  

d)                   When connecting thin-walled stainless steel pipes of Zhengkang brand with valves, water taps, water gauge and other heating accessories, never use threading but to use matching fittings to connect.   

e)                     Because stainless steel is of some heat expansion, steady rest and travelling rest must be set in suitable place, considering the place of bellows. Set only one bellow between the rests on the condition that the rests must have enough strength.  

f)   Stainless steel is one material of high anti-corrosion, not easy to get rust, with smooth surface. After every stage of stainless steel pipe installation, to fix additionally to avoid leakage caused by vibration that make the fittings of last stage loose.    

About other regulations: Besides, pay attention to the following matters during operation: 

1．During transporting the pipes, no heavy press, knock, crash, throw, bend and other activities to make the pipes deforming and cracking;  

2.          To make familiar with water supplying diagram, and check if the model and sizes of the pipes and fittings will reach the requirements. Don’t tear down the packages or pipe end caps before approval.  

3.            When installing the pipes into wall or pipe well or earth, except the pipe end mouth, there is no need to peel off the heat shrinkage film that covering the pipe, to protect the pipe surface away from lime, cement, grease and other soil, alkali and salt that will erode and pollute to pipes. When installing the pipe openly, after finishing installation and water pressure tests, take off the protective layer and handover.   

4.            When connecting thin-walled stainless steel pipes of Zhengkang brand with valves, water taps, water gauge and other heating accessories, never use threading but to use matching fittings to connect. 

5.            In concealed installation and adopting the cement mortar to make up, to use thermal insulating material to make sure there is gap between cement mortar and pipes, so that the concealed pipe can stretch out and draw back freely. 

6.            Because stainless steel is of some heat expansion, steady rest and travelling rest must be set in suitable place, considering the place of bellows. Set only one bellow between the rests on the condition that the rests must have enough strength. 

7.  When the pipeline penetrates into wall, floor as concealed installation, holes or grooves shall be reserved to match with build project to make sure the safety and convenience of installation. The reserved hole or groove shall accords with the following requirements: the hole size shall be 50-100mm bigger than the pipe outside diameter; the groove in wall shall be 20mm deeper than pipe outside diameter, 40-50mm wider than pipe outside diameter, and no less than 100mm of the room overhead line fair tube. 

7.            After finish every day or every floor installation in building construction, the uncovered shall be plugged, and done with pressure test with 2.5MPa. And in the second day, works can go on only the pressure is no lower than 1.6MPa; if the pressure is lower than 1.6MPa, operation must stop to check if there is leakage till the phenomenon disappeared, so to avoid difficulties in later pipline construction.    

8.            No alteration to the special tooling personally.