METHOD SATEMENT OF FIRE SYSTEM FOR OM ACCOMODATION METHOD SATEMENT OF WATER SYSTEM 1 0 2022 04 29 V K Hoan T D Thinh T N Khoa First Issue Rev Date Prepared Checked Approved Details of Revision Owner VUNG ANG II THERMAL POWER LLC Owner’s Engineer TOKYO ELECTRIC POWER SERVICES CO , LTD EPC Contractor PACIFIC CORPORATION JSC Subcontractor HOP LUC CONSTRUCTION JOINT STOCK COMPANY Project VUNG ANG II THERMAL POWER PLANT PROJECT Title METHOD STATEMENT OF WATER SYSTEM Document No VA2 OM MS ME WS 004 R.
General discription
Water supply and drainage system construction methods apply to areas including:
Family apartment, Management house, Multi-functional gym and medical house, supermarket and restaurant, park housre, guard house, substations and pumping stations
Figure 1.1-1 Working plan of waste supply system
Figure 1.1-2 Working plan of wastewater drainage system
Figure 1.1-3 Water supply and drainage diagram
Project materials
- Materials use at project for install of water system: Pump, piping, valve, gauges, water equipment, accessory…
In accordance with the technical specifications outlined in the Bidding Documents and Design Drawings, all primary supplies and materials must be submitted as samples along with their respective material certificates for approval by the Owner prior to their utilization.
List of machinery & tools
No Name Unit Quantity Note
4 Drilling machine Pcs 1pcs/5 person
6 Electrical jack Pcs 1pcs/5 person
7 Cutting machine Pcs 1pcs/5 person
8 Electrical Panel Pcs 1pcs/5 person
11 Hand tools Pcs 1pcs/1 person
12 Measuring tape Pcs 1pcs/1 person
13 Laser router Pcs 1pcs/5 person
14 Line marker Pcs 1pcs/1 person
Table 2.1 List of tools and machinery
+ Note: The certificated and relevant document of the special equipment will be submitted prior to use at site
2.3 List of Personal Protection Equipment (PPE)
1 Hi vis 7 Half Rubber Coated Gloves
2 Safety shoes 8 Plastic coated gloves
Table 2.2 List of safety equipment mobilization
Standards Required by Statutory Regulations
National technical regulation on rules of classification and grading of Civil and industrial buildings and urban infrastructures promulgated with circular
No.12/2012/ TT-BXD dated 28/12/2012 of the ministry of construction
2 Viet Nam building code urban engineering infrastructures promulgated QCVN 07
National technical regulation on domestic wastewater issued by decision
No.16/ 2008 /QD-BTNMT dated 31/12/2008 of the ministry of natural resources and enviroment
5 Public building- Basic rules for design issued by decision No.47/ 1999/
6 Drainage and Sewerage - External networks and Facilities - design standard TCVN 7957-
7 Reinforced concrete pips for water draining TCVN
8 Reinforced concrete culverts - Technical requirements 22TCN 159-86
9 Viet Nam Building code Regional and urban planning and rural residental planning 01:2008/ BXD
10 Internal water supply design standard TCVN 4513-
11 Water supply - Distribution system and facilities design TCXDVN 33
12 Documents on supply and drainage pipe are used in iso 9001 ISO 9001
13 Drainage system inside houses and buildings Regulations on construction and acceptance
No Work item Quantity Scope of work
1 Mechanical worker 5 Workers are rotated from one item to another depending on the actual construction
No Work item Site manager
Multi-functional gym and health care house
The Contractor forms a Project Management Unit to oversee the project, which includes an executive board, supporting departments, and dedicated construction teams responsible for executing specific work items.
Relationship between the Board of Management and the site management department
The Company's Board of Directors provides direct oversight to the departments and the Site Management Unit, assigning specific responsibilities based on expertise They actively guide and monitor the site manager to ensure effective contract execution, adherence to appropriate construction methods and processes, compliance with regulations, and maintenance of quality standards Additionally, they focus on technical management, equipment safety, and the efficient supply of materials and human resources.
The site management department, led by the Site Manager, is tasked with providing regular updates to the Board of Directors regarding the construction status and site management The Site Manager must effectively coordinate with relevant departments to ensure that all requirements are met and that construction progresses according to the design documents, maintaining the project's technical quality Additionally, the Site Manager is responsible for promptly addressing and resolving issues that arise in each construction area to ensure efficient operations.
The project manager is responsible for executing tasks assigned by the Board of Directors, overseeing human resources, technical aspects, quality control, and project progress Daily monitoring of the construction process is essential to ensure adherence to design specifications Effective coordination with the Owner, design consultants, and the Owner’s engineer, along with other relevant parties, is crucial for addressing issues that arise on the construction site.
TA DUC THINH Deputy Site Manager 0982.351.435
TRINH NGOC KHOA Site Manager 090.3468.016
DO DINH HUONG Mechanical Engineer 0359.445.933
In the absence of the site manager, it is essential to execute the assigned tasks effectively, ensuring all construction site operations are managed efficiently on their behalf.
Department of Progress, Technical and Quality Management
- The head of this department is the construction technical manager - responsible to the Site Management Unit for the technique, progress and quality of the work
The technical department oversees project progress and construction techniques, ensuring quality in every job They assist the Site Manager and on-site technicians while maintaining communication with Party A and engineers Their responsibilities include consulting on technical solutions, conducting acceptance work, preparing as-built documents, and maintaining a daily monitoring diary.
Safety, security and environment management department
The safety department is responsible for gathering, researching, and distributing legal documents related to labor protection across teams Additionally, it organizes training courses on labor safety for all employees at the construction site, managed by a dedicated full-time officer and supported by part-time site technicians.
Officers play a crucial role in maintaining safety, security, and environmental standards on construction sites They assist the Site Manager and technicians while being consistently present on-site Their primary responsibility is to implement measures that protect both personnel and equipment, ensuring a safe and conducive working environment.
The medical department is dedicated to safeguarding the health of staff and construction workers by providing essential care, including dispensing medications for minor ailments In the event of an accident, they administer first aid and determine if hospitalization is necessary for further treatment Additionally, the department regularly reports to the site Management Unit and the company's board of directors regarding the status of occupational accidents on the construction site.
The department overseeing workforce management plays a crucial role in monitoring and supervising employee payments, as well as allocating funds for materials and equipment This department maintains a strong connection with the direct construction teams and equipment divisions, ensuring efficient operations and resource utilization.
The technical management department plays a crucial role in ensuring the quality of materials and equipment supplied for construction projects Its responsibilities significantly impact the overall progress of construction, making it a vital factor in achieving successful outcomes.
- Follow the direction of the technical management department for each work area
- Includes teams: Construction motorbike, formwork + scaffolding + reinforcement + concrete, masonry + finishing, mechanical group, aluminum and glass, plaster + paint, electricity and water team, construction team
- Each team will include 01 team leader and 01 supervisor who is responsible for managing the team's human resources, progress, and quality before the project
The field organization model prioritizes quality and construction progress, showcasing a well-structured and planned approach It highlights the expertise of each production team while ensuring their dynamic performance.
- Well perform the registration of temporary absence with local authorities
- Ensure absolute security and order, social safety in the area
- Establish site rules and regulations on labor safety, organize for workers to study and strictly implement the set rules
- Workers entering and leaving the construction site must have a card provided by construction unit
- Survey at site before the installation
- Survey and understand the current progress of the main structure and the site with reference to Safety Management System and contract requirement and engineering due diligence
- When arranging the construction site, it does not affect the operation and general landscape, ensuring traffic, safety and environmental sanitation Ability to quickly
Proceed to other related works
Material Construction plan adapt to unexpected changes
- The layout of the construction site must be reasonable and convenient, minimizing dust and noise affecting the operation of the surrounding area and not obstructing the construction process
- Ensure reasonable construction without overlap causing work stoppage and unsafety
- Ensure security and order and good fire prevention
- Listing for all materials used for water system, making plan for submission, purchasing and installation
- Listing for all shopdrawing used for water system, making plan for submission and installation
- Listing for all methodstatement used for water system, making plan for submission and installation
5.1.1 Construction method of indoor water supply: a Preparation
- All PPr pipe, fittings, support materials, miscellaneous materials which have been approved by PAC contractor and Owner Inspector
- Large roofed warehouse to store pipe
- Check pipe quality during the transportation to construction site
Works are execute base on construction schedule and detailed approval drawing b Connection works
To connect PPR pipes and fittings, a specialized butt fusion process is necessary, utilizing a 220V power source to heat the pipe to 260°C for effective welding.
- To prepare the fusion welding machine & Drilling machine and cutter
- Check the pipe length required based on the approved shop drawing
- Clear the trench where install gasket and inside of connection joints
-Mark the desired length on the pipe and cut it by using a cutter or pipe cutter mounted on the fusion machine
Picture 5.1-1 Cutting of the pipe
- Push the en of the pipe to the welding depth into the welding tool
- After thermal treatment sucess, withdraw pipes and fittings out of the device then compress pipes with fittings, heating time refer supplier’s catalogues or use guide
Picture 5.1-2 Equal to Fitting’s depth and time schedule
- After the stipulated times heating quickly remove pipe and fitting from the welding tool
- Join them immediately until the marked welding depth is covered by the PP-R bead from the fitting
Picture 5.1-3 Heating up of the pipe and fitting
Picture 5.1-5 Pipe and fitting are aligning
- Press and hold the weld for 1 minute and hold the clamp Then wait until the cooling time is over, remove the clamp, the weld is completed
The melting time for pipes and fittings commences once they are connected at the appropriate weld depth, while the connection time starts when these components are joined together Cooling time refers to the period required for the weld to cool completely, and it is crucial not to expedite this process by using water or any other methods For the installation of the underground section of PPR pipes, specific techniques must be followed to ensure proper assembly and durability.
- Use ruler and white chalk to draw or use a wire soaked in white paint to locate the path of pipeline according to the approved construction drawings
- Carry out the construction of underground pipes and fix the pipes to avoid position deviation according to the approved construction drawings
Picture 5.1-6 : Typical plan with underground water supply pipe d Methods of installig the PPR pipe recessed wall:
- Read drawings, adjust the laser machine from the benchmark to the construction location
- Use ruler and white chalk to draw or use a string soaked in white paint to locate the path of pipeline according to the approved construction drawings
- Carry out watering on the wall that has been outlined To avoid dust for construction workers and ensure the surrounding environment
- Carry out locating positions of double link suspension, the construction Thread Rod, cut wall to create pipelines with brick cutter
- Installing optical hangers, recessed piping and connecting routes
- Use nails and steel wire to fix the pipe to the wall
- It is required to place mesh (anti-cracking after plastering the wall) at the cutting positions, two or more piping and at intersections, position of valve connecting fittings
- Check and review the installation of pipes and fittings
- Conduct the acceptance and installation of the system
Picture 5.1-7 : Installation of recessed water supply pipe e Construction methods and installation of corridor plan pipe:
- Read drawings, adjust the laser machine from the benchmark to the construction location
- Close the line, get mark on the ceiling to hang pipe
- Drill the ceiling to bolt, threaded rod and double link suspension
- Align the position, threaded rod fittings, install and connect pipes on the ceiling
When installing multiple parallel pipes at the same height, a single bracket can effectively secure them together For two or fewer pipes, a double link suspension system is recommended to ensure proper fixation and stability.
- Install pipe on the bracket, fix pipe to the bracket with bolt combined with rubber gasket to prevent pipe movement
- At positions of welding and connecting pipes, install bracket to increase the rigidity of system
- Align pipe in line then tighten uBolt
- Check and review the installation of pipes and fittings
- Conduct acceptance and installation of the system
- Conduct the system pressure test
* Detail installation of corridor horizontal pipe follow in approved shop drawing :
Horizontal distance of pipe hanger
Vertical distance of pipe hanger
Table 4 : Pipe hanger table, water supply pipe specifications
- Read layout drawings of vertical pipes, prepare materials and equipment for pipeline installation
LỚP CAO SU LÓT OÁNG
- Drop ball to mark along the axis, at positions of axis deviation, chisel to mark again
- Install floor bracket for vertical shaft, fix pipe with Ubolt and rubber washers
- Pipe hanger can be processed in advance at the factory
- Cut and connect pipe, mark pipe end, weld pipe at the shaft
- Align the whole line, tighten nut
- Install equipment on pipeline; gate valve, pressure relief valve, flexible coupling … Nominal inner diameter 15 20 25 32 40 50 65
Table of conversing nominal inner diameter to outside diameter PPr-PN10
Nominal inner diameter 15 20 25 PP-R pipe outside diameter D25 D32 D40
Table of conversing nominal inner diameter to outside diameter PPr-PN20
- Check and review the installation of pipes and fittings f Construction methods to return wall surface:
- After the Owner and PAC inspector complete the inspection, the Contractor will proceed to return the wall surface to the builder
- With the construction to return the wall surface, the contractor conducts aligning throats of the equipment according to specifications of equipment with ruler and leveling
5.1.2 Construction method of outdoor pipe system installation: a Preparation
- All HDPE pipe, support materials, miscellaneous materials which have been approved by PAC contractor and Owner Inspector
- Large roofed warehouse to store pipe
- Check pipe quality during the transportation to construction site
- Check the route for transport pipes to installation location
Works are execute base on construction schedule and detailed approval drawing b Excavation work
- Check and identify the pipeline line according to the approved construction drawings, stretch the rope to mark line to be excavated
Picture 5.1-9 Marked by sprinkling lime
Based on documents
Standards Required by Statutory Regulations
National technical regulation on rules of classification and grading of Civil and industrial buildings and urban infrastructures promulgated with circular
No.12/2012/ TT-BXD dated 28/12/2012 of the ministry of construction
2 Viet Nam building code urban engineering infrastructures promulgated QCVN 07
National technical regulation on domestic wastewater issued by decision
No.16/ 2008 /QD-BTNMT dated 31/12/2008 of the ministry of natural resources and enviroment
5 Public building- Basic rules for design issued by decision No.47/ 1999/
6 Drainage and Sewerage - External networks and Facilities - design standard TCVN 7957-
7 Reinforced concrete pips for water draining TCVN
8 Reinforced concrete culverts - Technical requirements 22TCN 159-86
9 Viet Nam Building code Regional and urban planning and rural residental planning 01:2008/ BXD
10 Internal water supply design standard TCVN 4513-
11 Water supply - Distribution system and facilities design TCXDVN 33
12 Documents on supply and drainage pipe are used in iso 9001 ISO 9001
13 Drainage system inside houses and buildings Regulations on construction and acceptance
Manpower for construction
No Work item Quantity Scope of work
1 Mechanical worker 5 Workers are rotated from one item to another depending on the actual construction
No Work item Site manager
Multi-functional gym and health care house
Responsibilities
The Contractor sets up a Project Management Unit to oversee the project, which includes an executive board, support departments, and direct construction teams responsible for executing specific construction tasks.
Relationship between the Board of Management and the site management department
The Company's Board of Directors provides direct oversight to the departments and Site Management Unit, ensuring that each department operates within its area of expertise They closely guide and monitor the site manager to ensure effective contract execution, adherence to appropriate construction methods and regulations, quality acceptance, technical management, equipment safety, and the proper supply of materials and human resources.
The site management department, led by the Site Manager, is required to provide regular updates to the Board of Directors regarding the construction status and site management issues The Site Manager must effectively coordinate with relevant departments to ensure compliance with project requirements, maintain continuous construction according to design documents, and uphold the technical quality of the project Additionally, the Site Manager is responsible for promptly addressing and resolving issues within each construction area to ensure efficient operations.
The project manager is responsible for executing tasks assigned by the Board of Directors, overseeing human resources, technical aspects, quality, and project progress They monitor the construction process daily to ensure adherence to design specifications and coordinate effectively with the Owner, design consultants, and the Owner’s engineer, as well as other relevant parties on-site.
TA DUC THINH Deputy Site Manager 0982.351.435
TRINH NGOC KHOA Site Manager 090.3468.016
DO DINH HUONG Mechanical Engineer 0359.445.933
In the absence of the site manager, it is essential to carry out the tasks assigned by them, effectively taking on the responsibility for all construction site operations.
Department of Progress, Technical and Quality Management
- The head of this department is the construction technical manager - responsible to the Site Management Unit for the technique, progress and quality of the work
The technical department oversees project progress and construction techniques, ensuring quality standards are met They support the Site Manager and technicians on-site while maintaining communication with Party A and consulting engineers Their responsibilities include providing technical solutions, conducting acceptance work, preparing as-built documentation, and maintaining a daily monitoring diary.
Safety, security and environment management department
The safety department is responsible for gathering, researching, and distributing legal documents related to labor protection across teams To enhance workplace safety, training courses on labor protection are organized for all employees at the construction site, overseen by a dedicated full-time officer and supported by part-time technicians.
Officers play a crucial role in maintaining safety, security, and environmental standards on construction sites They assist the Site Manager and technicians, ensuring their constant presence at the site Their responsibilities include implementing measures to protect personnel and equipment while fostering a positive working environment.
The medical department is dedicated to ensuring the health and safety of staff and construction workers by providing care for minor illnesses and dispensing necessary medications In the event of an accident, they conduct first aid on-site and, if required, facilitate the patient's transfer to a hospital for emergency treatment Additionally, the department regularly reports to the site Management Unit and the company's board of directors regarding the status of occupational accidents at the construction site.
The department oversees the management of personnel, ensuring timely payment to workers and allocating funds for materials and equipment Its close collaboration with construction teams and equipment divisions is essential for efficient project execution.
The technical management department plays a crucial role in ensuring the quality of materials and equipment supplied for construction projects This department is essential for maintaining construction progress, as it directly influences the overall product quality.
- Follow the direction of the technical management department for each work area
- Includes teams: Construction motorbike, formwork + scaffolding + reinforcement + concrete, masonry + finishing, mechanical group, aluminum and glass, plaster + paint, electricity and water team, construction team
- Each team will include 01 team leader and 01 supervisor who is responsible for managing the team's human resources, progress, and quality before the project
The field organization model prioritizes quality and construction progress, showcasing a structured approach to work and effective planning It highlights the expertise of each production team while ensuring their dynamism and adaptability.
- Well perform the registration of temporary absence with local authorities
- Ensure absolute security and order, social safety in the area
- Establish site rules and regulations on labor safety, organize for workers to study and strictly implement the set rules
- Workers entering and leaving the construction site must have a card provided by construction unit
Coordination at site
- Survey at site before the installation
- Survey and understand the current progress of the main structure and the site with reference to Safety Management System and contract requirement and engineering due diligence.
Work flow chart
Construction requirements
- When arranging the construction site, it does not affect the operation and general landscape, ensuring traffic, safety and environmental sanitation Ability to quickly
Proceed to other related works
Material Construction plan adapt to unexpected changes
- The layout of the construction site must be reasonable and convenient, minimizing dust and noise affecting the operation of the surrounding area and not obstructing the construction process
- Ensure reasonable construction without overlap causing work stoppage and unsafety
- Ensure security and order and good fire prevention
- Listing for all materials used for water system, making plan for submission, purchasing and installation
- Listing for all shopdrawing used for water system, making plan for submission and installation
- Listing for all methodstatement used for water system, making plan for submission and installation
Water supply system installation
5.1.1 Construction method of indoor water supply: a Preparation
- All PPr pipe, fittings, support materials, miscellaneous materials which have been approved by PAC contractor and Owner Inspector
- Large roofed warehouse to store pipe
- Check pipe quality during the transportation to construction site
Works are execute base on construction schedule and detailed approval drawing b Connection works
To connect PPR pipes and fittings, specialized butt fusion is necessary, requiring a 220V power source to weld the pipes at a temperature of 260°C The process involves specific steps to ensure a secure and durable connection.
- To prepare the fusion welding machine & Drilling machine and cutter
- Check the pipe length required based on the approved shop drawing
- Clear the trench where install gasket and inside of connection joints
-Mark the desired length on the pipe and cut it by using a cutter or pipe cutter mounted on the fusion machine
Picture 5.1-1 Cutting of the pipe
- Push the en of the pipe to the welding depth into the welding tool
- After thermal treatment sucess, withdraw pipes and fittings out of the device then compress pipes with fittings, heating time refer supplier’s catalogues or use guide
Picture 5.1-2 Equal to Fitting’s depth and time schedule
- After the stipulated times heating quickly remove pipe and fitting from the welding tool
- Join them immediately until the marked welding depth is covered by the PP-R bead from the fitting
Picture 5.1-3 Heating up of the pipe and fitting
Picture 5.1-5 Pipe and fitting are aligning
- Press and hold the weld for 1 minute and hold the clamp Then wait until the cooling time is over, remove the clamp, the weld is completed
The melting time for pipes and fittings begins once they are connected at the correct weld depth, while the connection time starts when the pipes and fittings are joined together Cooling time refers to the period required for the weld to cool completely; it is important not to shorten this cooling time by using water or any other methods Proper installation methods for the underground section of PPR pipes are essential for ensuring durability and effectiveness.
- Use ruler and white chalk to draw or use a wire soaked in white paint to locate the path of pipeline according to the approved construction drawings
- Carry out the construction of underground pipes and fix the pipes to avoid position deviation according to the approved construction drawings
Picture 5.1-6 : Typical plan with underground water supply pipe d Methods of installig the PPR pipe recessed wall:
- Read drawings, adjust the laser machine from the benchmark to the construction location
- Use ruler and white chalk to draw or use a string soaked in white paint to locate the path of pipeline according to the approved construction drawings
- Carry out watering on the wall that has been outlined To avoid dust for construction workers and ensure the surrounding environment
- Carry out locating positions of double link suspension, the construction Thread Rod, cut wall to create pipelines with brick cutter
- Installing optical hangers, recessed piping and connecting routes
- Use nails and steel wire to fix the pipe to the wall
- It is required to place mesh (anti-cracking after plastering the wall) at the cutting positions, two or more piping and at intersections, position of valve connecting fittings
- Check and review the installation of pipes and fittings
- Conduct the acceptance and installation of the system
Picture 5.1-7 : Installation of recessed water supply pipe e Construction methods and installation of corridor plan pipe:
- Read drawings, adjust the laser machine from the benchmark to the construction location
- Close the line, get mark on the ceiling to hang pipe
- Drill the ceiling to bolt, threaded rod and double link suspension
- Align the position, threaded rod fittings, install and connect pipes on the ceiling
For multiple parallel pipes at the same height, a single bracket can effectively secure them, while for two or fewer pipes, a double link suspension is recommended for stability.
- Install pipe on the bracket, fix pipe to the bracket with bolt combined with rubber gasket to prevent pipe movement
- At positions of welding and connecting pipes, install bracket to increase the rigidity of system
- Align pipe in line then tighten uBolt
- Check and review the installation of pipes and fittings
- Conduct acceptance and installation of the system
- Conduct the system pressure test
* Detail installation of corridor horizontal pipe follow in approved shop drawing :
Horizontal distance of pipe hanger
Vertical distance of pipe hanger
Table 4 : Pipe hanger table, water supply pipe specifications
- Read layout drawings of vertical pipes, prepare materials and equipment for pipeline installation
LỚP CAO SU LÓT OÁNG
- Drop ball to mark along the axis, at positions of axis deviation, chisel to mark again
- Install floor bracket for vertical shaft, fix pipe with Ubolt and rubber washers
- Pipe hanger can be processed in advance at the factory
- Cut and connect pipe, mark pipe end, weld pipe at the shaft
- Align the whole line, tighten nut
- Install equipment on pipeline; gate valve, pressure relief valve, flexible coupling … Nominal inner diameter 15 20 25 32 40 50 65
Table of conversing nominal inner diameter to outside diameter PPr-PN10
Nominal inner diameter 15 20 25 PP-R pipe outside diameter D25 D32 D40
Table of conversing nominal inner diameter to outside diameter PPr-PN20
- Check and review the installation of pipes and fittings f Construction methods to return wall surface:
- After the Owner and PAC inspector complete the inspection, the Contractor will proceed to return the wall surface to the builder
- With the construction to return the wall surface, the contractor conducts aligning throats of the equipment according to specifications of equipment with ruler and leveling
5.1.2 Construction method of outdoor pipe system installation: a Preparation
- All HDPE pipe, support materials, miscellaneous materials which have been approved by PAC contractor and Owner Inspector
- Large roofed warehouse to store pipe
- Check pipe quality during the transportation to construction site
- Check the route for transport pipes to installation location
Works are execute base on construction schedule and detailed approval drawing b Excavation work
- Check and identify the pipeline line according to the approved construction drawings, stretch the rope to mark line to be excavated
Picture 5.1-9 Marked by sprinkling lime
For effective earth excavation, utilize either manual methods or an appropriate excavator, ensuring to regularly monitor the excavation depth in accordance with the construction drawings for each pipeline Additionally, prioritize safety throughout the excavation process.
- Excavate correctly requirement depth and width
- Excavation level shall be deeper than level of pipe bottomn 100 mm
Picture 5.1-11 Detailled elvation of pipe ditch
Picture 5.1-12 Check elevation of ditch bottom
Picture 5.1-13 Check width of ditch bottom
- Conduct compact sand bedding layer until reach K = 90 MDD by compactor
Picture 5.1-11 Compaction of the ditch bottom
- After checking that the construction pipeline meets the requirements, proceed to connect and install the pipe c Preparation before welding
- Install the machine, connect the power and hydraulic wires
- Check the machine, hydraulic oil, suitable voltage, run dry
- Set the appropriate heat disk temperature (For PE, it is usually between 195-2100C)
- Set the pipe welding hydraulic pressure (P) in accordance with the size and thickness of the pipe to be welded
- Set the appropriate heating time (refer to the setting parameter table)
- Set the appropriate welding time
When it comes to the duration of the pipe welding process, it may not be essential to equip the machine with additional tools like watches or timers This is due to the fact that various time intervals occur continuously throughout the welding process, making such equipment less convenient.
* Some things need to be noted:
- Wear gloves during blade inspection or heat disk movement
- Heat disk and pipe bevel disk must be placed in separate jigs when not in use
- Not use the machine in case of rain, wet working area or area with flammable and explosive substances
- The temperature of heat disk is very high, at 260℃, so be careful to avoid burning
- The person using the machine must be a person who has been trained
- The surface of heat disk must always be cleaned with soft cloth to avoid scratching the non-stick paint coating
- Before welding, clean the area to be welded, avoid dirt for the welding surface, affecting the quality of weld d HDPE welding:
- Clamp the end of 2 pipes to be welded Two ends of pipe must be balanced (if the pipe has colored stripes, clamp so that the colored stripes are symmetrical)
- Move the pipe bevel disk between two pipes to be welded
- Open the switch for the pipe bevel disk to operate, note the rotation direction of bevel disk
To achieve a continuous strip of HDPE from the pipes, press them together and shave until peeling occurs on both sides Once consistent peeling is noted, release the pressure and separate the pipes without turning off the shaver Stopping the shaver mid-operation will result in an end cut-mark, necessitating a repeat of the shaving process.
To ensure proper alignment of pipes after using a pipe-chamfering machine, it is essential to remove the machine, re-match the pipes, and check their alignment Even with continuous peeling on both sides, misalignment can occur due to uneven pressure from the clamps A simple solution is to slightly re-tighten the nuts on either side If this does not resolve the issue, inserting a shim between the clamp jaws and the pipe can effectively concentrate pressure and align the pipes Remember, if a clamp is opened during this process, the shaving operation must be repeated for optimal results.
- Remove chips inside the pipes on both sides, all chips scattered under the pipes, and also inside the machine
- Put heating init between 2 pipes end and start hydraulic press to push 2 pipes together against the heating init
- Heat the 2 pipe ends until the required melting layer thickness is reached
Pipe Size (mm) Melting thickness H (mm)
Table 5: Melting round thickness relative size
- Turn off the hydraulic press and remove the heater
- Start hydraulic press to bring the pipes together quickly to reduce the temperature drop
- Do not move or remove the press and pipe during weld cooling
Table 6: Parameter of HDPE welding
- All pipe must be pressure test after connection and installation
-The piping system is tested according to the method: Using water as the pressurizing medium inside the system and tested at ambient temperature
- Prepair : booster pump, pressure gauge, stop valve, pipe seal cap
-System water inlet valve: must be installed at the lowest point of the system
- Bleed valvemust be installed at the highest points of the system One or more bleed valve can be installed on the system
- Selection of pressure test for each pipe segment or line is important, it depends on the length of pipe, pipe's type, working pressure
- Highest test pressure must be 150% times normal working pressure of the pipe
- Connect booster pump into one pipe end
-Start the pump to fill up water inside the pipe until the testing pressure is reached
- Each type of pipe will supply a different test pressure:
- Keep the pressure stable for 6 hours Monitor if pressure drop is not more than 5%, it is acceptable.
- In other cases, it is necessary to repair and re-test pressure until requirements are reach
- All processes must be witnessed by PAC and Owner inspector Inspection record of acceptance and sign the 3 parties
- After installation and inspection finish, landfilling will be made by hand or excavator
- Requirements in the process of backfilling, layer surrounding the pipe must be soft sand Avoid filling rocks, gravel, hard objects directly on the pipe
- In the case of pipes crossing or under the road, a steel pipe must be installed to protect the HDPE pipe
- Backfilling work is carried out according to the approved drawings as follows:
Detailled excavation & backfilling section of water supply pipe under sidewalk
Detailled excavation & backfilling section of water supply pipe under road.