磷酸管道施工方案(英文版)

CONTENTS
1、Generals (2)
2、Compilation basis (2)
3、Construction procedure plan (2)
4、Construcion Preparation (3)
5、Pipe Prefabrication (4)
6、Pipeline Erection (7)
7、Pipe welding and welding inspection (10)
8、Welding method and technology (12)
9、Requirement for welding quality (13)
10、Requirement for pressure testing of pipeline (14)
11、Blowing off and flushing of piping (15)
12、Quality Guarantee Measures (16)
13、Safety protective measures (18)
14、Construction labours and machines (20)
1、 Generals
This plan is compiled for process pipe installation of PA unit.Work scope includes inspection of pipe materials and fittings, pipe prefabrication and installation, degreasing and pickling of stainless steel pipes, and pipeline detection. The work quantity shall include approximately 68000 din. The pipe material shall include carbon steel,stainless steel, glass fiber reinforced plastics, lined pipes and PE pipes etc. The pipeline prefabrication shall be done in the prefabrication shop outside the field.
2、 Compilation basis
This construcion plan is compiled according to the following files :
1、Code for Construction and Acceptance of Industrial Metallic Pipeline Engineering GB50235-2010
2、Code for Construction and Acceptance of Field Equipment and Industrial Pipeline Welding Engineering GB 50236-2011
3、Code for construction and acceptance of petrochemical industry toxic and combustible medium pipeline engineering SH 3501-2011
4、WUHUAN related design drwaings and technical code.
5、Pipe vendor＇s Site Handling, Installation and Welding Manual
3、Construction procedure plan
3.1 Pipelines prefabrication procedures
Constructionpreparations→materialtake-over→pipelinessurfacerust removing →marking→measures check-up→material cutting→bevel machining→weldjointsinspection→couplingand alignment→spot weld→check-up (weld joints preheating)→welding→visual inspection→PWT→check and inspection (dimension, hardness, NDT)→pressure test→protection→identification
3.2 Piping installation procedures on the site
Delivering prefabricated piping spools to the site→inside pipes cleaning→
tubing and support installation→piping spools coupling and alignment and spot weld→check (dimension, weld opening)→(preheating)→welding→visual inspection→(PWT)→inspection (dimension, hardness, NDT)→inside pipes purging→system pressure test→corrosion proof and insulation
4、 Construcion Preparation
4.1 Technical clarification: Technical clarification shall be made to field construction personnel before commencement to make them get to know project generals, content, work period, quality requirement, key points and difficulties, and to clarify each responsibilities and duties in construction. The operators with the certificate shall be checked, and make HSE training toall personnel involved in construction. Responsibility for personnel involved in constructionis to read the drawing carefully, get to know design purpose, and be familiar with the process, main technical specification for the pipe( pressure, temperature, conveying medium, corrosion situation, pipe fitting and welding materials), design basis and construction requirement etc. Each dimension, coordinate and elevation on the drawing shall be checked and verified carefully, including that all pipe materials, valves and other fitting whether conforming to the drawing, as well as material, specification and quantity of all listed materials and fitting. Before mobilization for construction, all constructors shall be trained for comprehensive safety& civilized construction education to strengthen awareness of quality, safety and civilized work during construction. Make them to know actual situation on construction site, and keep them know of site first aid facility and emergency assembly point.
4.2 Check machines&tools: count all machines and tools involved in the installation. Check conditions of installation equipment, machines and tools. Check electrical machines and see if they are running normally and reliably. Check conditions of testing tools. Unqualified ones shall be replaced or repaired in a timely manner which shall be mobilized after being labeled by maintenance department.
4.3 All pipe materials, pipes, valves and welding materials shall be attached with material quality certificate, content and form of which shall be in compliance with manufacturing standard requirement of correspondence materials. And they also should be inspected as per GB50235-2010 and SH 3501-2010 requirepment after mobilization.
4.4 Valves shall be preformed intensity and leakage test as per standard requirement. For the accepted valves, "Acceptance" would be labeled in time, and test report would be filled out. For Safety valves, it shall be checked and debugged as per requirement in local boiler inspection institute, and it shallbe lead sealing after acceptance, debugging record included.
4.5 All materials shall be classified and stacked in orders with distinct identification. No placing together for different materials.
5、Pipe Prefabrication
5.1 Pipe prefabrication shall be standardized prefabrication. Pipeline drawing and single line drawing shall be read before prefabrication, weld crater on the isometric drawing shall be labeled, pipe system No. and prefab order marked, as well as each assembly elements' order. Location for site fastening weld crater shall be reserved, free spool and close spool of pipe segments and prefab degree shall be marked, and close spool shall be processed according to the installation length after site measurement.
5.2 Storage for piping components and transplant marking: piping components should be safekept during construction, no damage or color code confusion is allowed. The marking on the pipe should be distinct, and transplant existing marking on the pipes prior to cutting. Carbon steel pipe fittings shall be kept separately with stainless steel fittings.
5.3 First weld seam of elbow and flange for pipe prefab would be welded before surface treatment, and the other prefab work should be done on the site prefab area.
5.4 Pipe Cutting
5.4.1 Small sized C.S pipes shall be cut using cutting machine, and be beveled using grinding machine; large sized(above 3″) pipes can use oxy acetylene for cutting and the bevel shall be ground. S.S pipe size below 3″will use abrasive wheel cutting machine with special grinding wheel, and those above 3″shall use plasma-cutting machine. The PE pipe can be cut by gringding machine or hack saw. Suitable grinding disc shall be selected and cutting shall be straight.Aftercutting ,the PE pipe surface should be shaved.
5.4.2 Quality requirements for steel pipe cutting: the cut surface shall be flat without any cracks, laminations, burrs, pitting or other defects, if exist, they shall be removed.
5.4.3 Bevel end slope deviation△≤1% of O.D of pipe, and not more than 3mm.
5.4.4 For steep pipes that are already cut, each pipe segment shall be marked with line number and segment number, and their service location shall be marked on construction drawings.
5.5 Bevel chamfering
5.5.1 Bevel chamfering of pipe segments after cutting shall be performed by angle grinder or internal grinder.
5.5.2 In accordance with Appendix B (ordinary bevel types and sizes of pipe welding)of piping construction code GB50235-2010, bevel chamfering shall be executed in compliance with pipe material and pipe wall thickness.
5.6 Pipe seat and part of pipe supports shall be prefabricated in the prefabrication area. The supports shall be fabricated such that their form, material, dimension, accuracy meet requirements in the pipe support standard provided. The surface shall be flat. The welding shall be fixed without defects like missing weld, insufficient weld or cracks. The welding surface shall be smooth without any spatters. Any welding distortion shall be corrected. Rust-proofing treatment shall be performed for fabricated supports in a timely manner, and shall be properly marked.
5.7 Piping fit-up
5.7.1 Pipe assembly shall be performed on the pipe fabrication platform.
5.7.2 For stainless steel pipe assembly, δ=3mm rubber sheets shall be furnished on the platform for separation against carbon steel plate. Carbon steel tools are not allowed to strike S.S pipes.
5.7.3 Pipe assembly tolerance shall meet standard requirement, and the inspection method involves measurement with Angle square, steel plate ruler and steel tape. Assembly space shall be 2~3mm.
5.7.4 Offset of pipe inside in assembly shall be Less than 10% of pipe wall thickness, and no more than 2mm.
5.7.5 Allowable deviation of fabricated pipe segments shall be in conformity with the following table requirement. After inspection, corresponding identification shall be marked. The pipe shall be cleared without sand, slag, scrap iron or other inside, and then shall be placed in a fixed location after closing the end. Allowable deviation in dimension of pipe segments prefabrication
5.7.6 Nondestructive test of fabricated pipe orifice shall be executed in proportion after pipe prefabrication. For unacceptable, identification shall be made, repair and re-inspect work would be conducted. For acceptance pipes, marking shall be made in a timely manner.
5.7.7 Pipe support can be fabricated as the pipes are prefabricated. The
supports shall be fabricated such that their form, material, dimension, accuracy meet pipe drawing requirement. The surface shall be flat. The weld shall be fixed without any defects like missing weld, insufficient weld or cracks. The welding surface shall be smooth without any spatters. Any welding distortion shall be corrected. Rust-proof treatment shall be conducted for fabricated pipe supports in a timely manner, and shall be properly marked.
5.7.8 For primary instrument, each type of discharging, reverse flushing pipe or standard pipe support, prefabrication work shall be performed by professional after knowing specification and quantity as per the drawing, which also shall be safekeeping by professional.
5.7.9 During the prefabrication and transport of flanges, they shall not be put disorderly, and shall be handled with special care and kept well in order, to avoid damage to the sealing surface of flange. After delivery of flanges, their surface must be protected with blind flange that made of three-ply board, which shall be fastened to the flange face with band.
6、Pipeline Erection
6.1 Pipeline erection sequence shall be large sized pipe first, then small sized pipe; first main pipe, then branch pipe. Besides, construction shall be conducted as sequence of difficult after easy ones. Easy-cracked or easy-collided pipeline shall be installed at last. This shall make pipeline installation engineering performing in a reasonable way.
6.2 Pressure pipeline execution plan shall be reported to the local safety authority in advance for filing according to Examination provisions for safety&quality supervision of pressure pipeline installation.
6.3 Basic requirement of pipeline installation
6.3.1 Qualification of alignment of equipment connecting to the pipeline, and fixation completion.
6.3.2 Site pipeline shall be hoisted with soft nylon sling.
6.3.3 Any change of site materials shall be furnished with material substitute list
provided by design institute.
6.3.4 Plugging shall be done to both ends of pipe on the site to keep clean. No opening is allowed.
6.3.5 Allowable deviation in dimension of all pipeline installation ( seeblow)
6.4 Installation requirement of stainless steel
6.4.1 Nylon sling shall be used for lifting work.
6.4.2 It is not allowed for S.S pipe to get direct connection with other pipes for site installation, as well as no strike by the hammer. If mechanic damage is found on the pipe surface, finishing work shall be made and acid-washing passivation treatment shall be performed.
6.4.3 Mechanical or plasma cutting shall be used for stainless steel. When cutting work or bevel ground is done by abrasive wheel, special cutting blade or grinding wheel shall be adopted.
6.4.5 Before welding, S.S weldment bevel and its both sides with 100mm shall be smeared with special protective paste to prevent spatters from attaching pipes.It is not allowed for S.S pipe to get direct connection with C.S support. S.S gasket, plastic or rubber gasket without chloridion shall be filled between support and pipe.
6.4.6 Arc strike on the raw material is not allowed when welding. Dirt and oxidation film damage shall be prevented when joint welding.
6.5Installation requirement to special piping
6.5.1 Installation requirement to FRP piping
6.5.1.1 The glass fiber reinforced piping in this project is factory prefabricated as per the size and specification in the drawing, and connnected section by section, with flange for each section. During the construction, the sealing of joint at flanges must be ensured, the sealing gasket shall be placed properly, the bolts shall be fastened symmetrically with suitable torque.
6.5.1.2 Mechanic cutting can be applied to glass fibe pipes, but layering and peeling are not allowed. The pipe shall have smooth surface, and flaking of surface layer is not allowed. Color shade,bubble and crinkle due to degrease of glass fabric are allowed, but those shall not exceed the thickness tolerance after retification, slight crinkle in inner wall of pipe is tolerable.
6.5.2 Installation requirement to lined pipes
6.5.2.1 The lined piping in this project is factory prefabricated as per the size and specification in the drawing. The pipe section shall be prefabricaed first, then lined, and after that, sent to site for installtion.
6.5.2.2 The prefabrication is the same with carbon steel pipe, according to specification and relevant technical requirements.
6.5.2.3 After prefabrication, the pipes shall be lined in consolidation.
6.5.2.4 Special care must be made in transport of lined pipes,to avoid damage of flange sel surface and lining. During installation,it is not allowed to knock lining flanging.The round of inner gasket of flange shall parallel and level. Regarding flanges smaller than DN 125, the inner diameter tolerance shall be +2.5mm,and for those larger than DN125, the inner diameter tolerance shall be +3.5mm; The outer diameter of flange shall exceed the sealing surface of lining mterialwhthin the flange, and the thickness of gasket should be 2.5~5mm . While connecting pipes,flange shall be kept in parallel, and it is not allowed to to eliminate the
deflection by fastening the bolts, and it should not to remove defects such as deviation, stagger or decentraction of flange end face by adding partial or multilayer gasket.The flange shall be kept in the same axial, the center deviation of bolt holes shall not exceed the hole diameter by 5%, to make sure free penetration of bolts. The bolts must be fastened symmetrically, and after fastening, the bolt length exposed shall be less or equal to 2 times of thread pitch. If shorter bolts are used,their top shall parallel with bolts. For bolts for pipes with fluid temperature over 100 degree, nuts shall be painted with lubricats such as copper sulphide or graphite oil. Regarding piping high over the ground,it is not allowed to first connect several pipes and then lift.Thepipline shall be installed on by one. During the istallation, fire source must be kept away, and no fire work on lined pipe is allowed. The last adjusting pipe section shall be not lined,and after the entire pipeline is completed, it shall be adjusted in length, then removed for lining.
7、Pipe welding and welding inspection
We shall conduct welding construction work strictly conformity with correct welding procedure and technology requirement, scientific and reasonable management method. Welding inspection work also shall be valued.
7.1 Generals
7.1.1 Welding operation instruction shall be compiled as per welding procedure before welding construction, which shall be performed by the welder according to the instruction. If piping material welding is not included in the existed welding procedure qualification, materials excluded shall be conducted for welding procedure qualification.
7.1.2 The welder shall be able to work for acceptable welding project after he possesses valid welder certificate issued by local labour department or national quality supervisory authority. The welding of type of steel for the first time the welder conducted, technical ability training shall be executed, and work on position after test acceptance.
7.1.3 Nondestructive testing company and operators shall perform work only after obtaining qualification certificate issued by labour department and permission approved by WPC or Owner.
7.1.4 Welding rod baking, stationary temperature and time shall be executed strictly as per welding rod specification requirement. Welding rod shall be put in the welding rod dryer to keep dry.
7.1.5 If one of the following situation of pipe welding environment emerged, no protective measure is taken, welding work shall stop immediately.
1、When manual arc welding conducted,wind velocity is greater than or equal to 8 m/sec; when manual argon arc welding performed, wind velocity is greater than or equal to 2m/sec;
2、Relative humidity is more than 90%;
3、When raining weather comes;
7.2 Welding technologic requirement
7.2.1 welding technology
1、Argon arc welding are required for welding seam.
2、Argon welding shall be used for butt seam of process pipe less than 3”.
3、Manual arc welding shall be used for socketweld.
7.2.2 Selection of welding material
7.2.3 Welding rod baking, issuing and recycling
7.2.3.1 Baking temperature and time of welding rod shall strictly meet instruction requirement.
7.2.3.2 Appearance inspection of welding rod shall be performed before baking. Welding wire with coating cracking, falling, eccentric or damping shall be forbidden for use.
7.2.3.3 Temperature shall be prevented from shock cooling or heating when welding rod baking, to avoid coating cracking or falling.
7.2.3.4 Welding rod shall be put in the welding rod dryer for use after issuing, but time shall not exceed 4hours, otherwise, baking again and re-baking shall not be performed over two times.
7.2.3.5 Each welder shall be provided with at least one dryer, and each dryer shall only be placed one type of welding rod.
8、Welding method and technology
8.1 Welding specification, including welding rod, welding parameter and requirement shall comply with welding procedure specification WPS compiled in this project.
8.2 When d≥150mm, center distance between two welding seams on straight pipe segment shall be more than or equal to 150mm; and it shall be more than or equal to outer diameter of pipe when d<150 mm.
8.3 Tack welding shall be symmetric position when weld assembly. When removing bridge typefixed plate, keep base metal not damaged and grind base metal surface smooth by abrasive wheel. If base metal damaged, patch weld shall be conducted as per welding procedure specification. Patch weld shall be inspected as per material and inspection requirement. The welder shall be qualified for construction after test qualification.
8.4 When performing tack weld and formal welding, arcing shall be forbidden on the base metal. Welding rod shall be available only after being baking as per requirement.
8.5 Sealing weld shall ensure weld bottom full penetration. Fusion situation of both sides of butt weld seam bottom shall be paid more attention to make sure fusion in good condition. Clean dirt between weld layers. The second layer welding shall be performed after no defects existing on the surface. No undercut is allowed for both sides of welding seam when cap weld. Each welding seam
shall be completed at once, especially for those quenching-tendency material. If unexpected situation happening or uncompleted, thickness shall be increased to prevent cracking after sealing weld.
8.6 After welding seam finished, undercut and bulge on weld surface shall be trimmed, and spatters shall be cleaned.
8.7 When repair for inspection unqualified weld, reason shall be found out. Repair work shall be conducted as per welding procedure specification. For repair work on one part position, less than three times for carbon steel, less than two times for alloy-steel or stainless steel. If the limit exceeded, report to the welding technical leader, make detailed repair plan, and repair work shall be performed after approval from the technical leader.
9、Requirement for welding quality
9.1 Weld surface quality shall comply with following requirements:
9.1.1、No crack, lack of fusion, porosity, slag inclusion or spatter is permitted. 9.1.2、o undercut for weld surface of stainless steel pipeline. Undercut shall be less than 0.5mm for other material pipeline. Total undercut length shall be less than 100mm, and total undercut length on both sides shall be less than 10% of total weld length.
9.1.3、The weld surface shall not be lower than that of base metal
9.1.4、Fillet height of fillet weld shall be in conformity with design requirement, which appearance shall be even and smooth. No crack, porosity, slag inclusion or other defects on the surface is permitted. Undercut depth shall be not more than 0.5mm.
9.2 Non-destructive inspection.
9.2.1 Only after acceptance for pipeline visual inspection, nondestructive testing for weld shall be performed.
9.2.2 When weld defects are inspected exceeding standard, repair work shall be conducted and further inspection followed.
9.2.3 When one unqualified weld are found, other two welds of the same lot
performed by the welder shall be inspected. If two weld are found unqualified, double welds inspection shall be conducted. If unqualified weld found, all welds of the same lot welded by the welder shall be inspected.
10、Requirement for pressure testing of pipeline
10.1 Conditions
10.1.1 The following documents shall be provided:
（1）Pressure test record
（2）Welding job logging, isometric drawing, radiography inspection layout drawing;
（3）Nondestructive inspection report and report for postwelding heating treatment and hardness test;
（4）Design modification and material substitute document.
10.1.2Piping system shall be installed as per design requirement;
（1）Form, material and installation location of pipe support and hanger shall be correct with required quantity. Secureness and welding quality shall be acceptable.
（2）Welding work completed, weld quality test accepted; necessary heating treatment and hardness test completed.
（3）Weld and other parts to be inspected shall be visually available.
10.1.3 According to design requirement, testing package and pressure test plan has been compiled based on working pressure medium. Draw out pressure test system drawing, which has been approved.
10.1.4 Regulating valve, safety valve, filter, flow orifice plate, flowmeter which can't be involved in pressure testing shall be removed. Temporary pipe nipple or temporary blind plate shall be adopted.
10.2 Pressure test
10.2.1 Pressure test shall be performed as per pressures specified in the pipe pressure test list provided by design institute, and testing medium shall be
selected according to design specification.
10.2.2 During pressure test, the system shall be vented of air through vents. The pressure rise shall be slow until test pressure, stop for 10min, then lower to design pressure and keep for 30min. The test is qualified if no pressure drop, leakage or visual distortion occurs.Any leakage found during test shall not be repaired with pressure. Re-test after repair until it is qualified.
10.2.3 When the pressure test is qualified, lower the pressure slowly, and the test medium is suitably discharged. Discharge test water into nearby sewage ditch or rain sewage pipe. Temporary blind flange, spool, support that are not used in the purging shall be removed and re-installed in a timely manner. Maintain pressure test record.
10.2.4 When pressure test of Austenitic stainless steel is performed, chloride ion content shall be not more than 25ppm.
10.2.5 Minimal pressure for hydrostatic test shall be no less than 1.5 times of design pressure.
11、Blowing off and flushing of piping
11.1Preparation
11.1.1 Pipe purge and flushing shall be performed after pressure test.
11.1.2 Purge details shall be prepared in accordance with purge plan provided by the owner.
11.1.3 Prepare temporary purge and flush pipe, temporary filter, by-pass pipe or separation blind flange, and mark on the isometric diagram.
11.1.4 Orifice plate, regulating valve, throttle valve, safety valve and some easily damaged instruments shall be not involved in purge, which shall be removed and replaced by blind flange and pipe nipple before purge and flush.
11.1.5 Purge and flush method: select purge and flush method as per process medium provided by the design institute, which specifically include water flush, air purge, steam purge, etc.
11.2 Water flushing
11.2.1 Clean water shall be used. Flush water for stainless steel pipe shall have CL at 25PPM or lower; Pressure for flushing shall be not more than working pressure, maximum flow speed shall be used for flushing.
11.2.2 Branch flushing shall proceed after main pipe is cleaned.
11.2.3 Visually check water color and transparency to see if they match those at the pipe inlet. The qualified pipeline shall have the water drained.
11.2.4 Pipeline after water flushing shall be dried by compressed air as per design or the owner's requirement.
11.3 Air purge
11.3.1 Use non-polluted air, the purge pressure shall not exceed the operating pressure.
11.3.2 Purge main pipe before branch.
11.3.3 Equipment is not be purged, separate them from pipes, and protect the equipment from rust and contaminates.
11.3.4 The purge opening shall be clearly marked against personnel damage.
11.3.5 Purge outlet shall be checked by the Owner, supervisor and site responsible person, it will be qualified if there is no rust, or other foreign matters.
11.4 After flushing and purging are qualified( confirmed by the supervisor and the owner), the pipeline outlet shall be re-assembled in opposite order of disassembly. Use formal gasket for blind flange. The supervisor is to inspect re-assembly and confirm. Maintain purge and flush record.
12、Quality Guarantee Measures
12.1 Quality system shall be executed strictly according with The Third Level MangementDocument quality system requirement. Especially pay more attention on personnel training, qualification review, material inspection, welding procedure evaluation, inspection of equipment&tools and each quality control point.
12.2 Document and drawing management: drawing, schedule, technical specification liaison sheet, material substitute list shall be controlled and
managed by specified staff, and maintain the record. Each technician shall prepare for original construction technical documents and completion documents, assist with construction team to maintain each type of construction record. Construction technician shall keep daily construction logging.
12.3 Material management: material documents shall be managed by material controller, such as product certificate, material quality instruction, material list collecting and issuing. After familiar with isometric diagram, material list and budget, material controller shall write limit material requisition, and check&accept quality, specification and quantity of the material when picking the material. Confirm the certificate(or copy) and delete on the computer. The receiver shall make signature. After picking into warehouse, the material shall be labeled and tagged according to specification, model, and quality. Based on above procedure, material controller shall issue material to the team. Material requisition and issuing shall be bound into document for reference. Material transported directly to the site after picking also needs for record, and locate it in the specified location and stack orderly as per different quality. All material shall be marked for different quality after cutting ,especially for stainless steel.
12.4 Welding management: Welding professional engineer and charger shall be allocated on project department, who shall be responsible for welding work, including marking welding junction no., welder no. And NDT part on isometric diagram, fill out the NDT authorization sheet, keep contact and cooperation with NDT lab.Weld preheating and heating treatment: maintain penetration report, welding and heating treatment record, manage baking, storage and keeping work for welding rod. Each welder shall have a fixed number. Welding test lab of the company shall send the sheet of qualified welders with name, number and qualified project to the construction group and inspection department for review. After welding, steel seal for carbon steel pipe shall be done near the weld, or seal with marking pen for stainless steel pipe, which shall be marked on isometric drawing.Keep record for welding rod baking(including brand number,。