Method Statement for Water Piping Copper (Hot and Cold) Installation

This method statement for water piping copper (hot and cold) installation is to ensure that all the area and other related activity is executed safely and in accordance with the project specifications. This MST establishes all quality assurance/quality control activity is conducted in a systematic manner, work is inspected and conformance is verified and documented for the project as specified in specifications and instructions.

Scope

This method statement for water piping installation is applicable to ensure that all hot and cold water piping copper installations with complete accessories and workmanship are correct, acceptable, functional, and conform to the project specification and manufacturer’s recommendation.

References

Project Specifications
Approved Shop Drawings/IFC Drawings
Approved Material Submittal

Abbreviations

QC Quality Control
QA Quality Assurance
HSE Health, Safety and Environment
MEP Mechanical, Electrical & Plumbing
ITP Inspection & Test Plan
MST Method Statement
PPE Personal Protective Equipment
MSDS – Material safety data sheets
RSK Risk Assessment
PQP Project Quality Plan
QCP Quality Control Procedure
INR Inspection Request

Responsibilities

General

1. The Project Manager (MEP) will be responsible to manage, execute, complete and handover the construction activities within approved budgets and resources in compliance with Project Requirements as specified in Project Specifications. He will be overall in charge of implementing the Method Statement in accordance with QA/QC and HSE requirements.
2. The Construction Manager will be responsible for managing construction activities and will lead and communicate with site Supervision, Subcontractors, and vendors to assist them in working on the project schedule by conforming to QA/QC and HSE requirements at the site.
3. HSE Manager will be responsible for plan, coordinate, and implement issues and directives within the organization. He ensures safe environmental working conditions for all employees.
4. QA/QC Manager will be responsible for supporting the project team in implementing and maintaining Quality Management System for the project through PQP, ITP, MST, and Procedures in compliance with project specifications, codes, and standards.
5. HSE Officer will ensure enforcement of safety procedures in accordance with the approved HSE Plan. Will be closely monitoring the site engineer’s strict implementation of the MS and Risk Assessment, the use of proper tools and equipment to maintain safety certifications of equipment and their adherence to safety regulations, reporting of any unsafe work, or stopping work that does not comply with HSE procedures.
6. The Site Engineer will be responsible for carrying out all construction-related activities with compliance to HSE and QA/QC requirements as per contract specifications, drawings/documents, codes, and standards.
7. QA/QC Engineer will be responsible for conducting inspections as per PQP.
8. The supervisor/foreman will be responsible for coordinating all works and workers related to the job.
9. Electrician/other tradesmen will be responsible for assisting his superiors during all construction work-related activities following HSE and QA/QC requirements.
10. Store in-charge receives and inspects all incoming materials and reconciles with documents; processes and distributes documentation; reports, documents, and tracks damages and discrepancies.

Handling, Storage and Transportation

1. All materials shall be handled/transported/stored in an optimal way that will not cause damage to them. Pipe shipping, storage, and handling shall comply with the manufacturer’s recommendations. The material will be delivered at the site in undamaged condition, in the manufacturer’s packaging, with identifying labels intact and legible.
2. Each shipment must be blocked and securely fastened to avoid damages during transportation.
3. Unloading at the site must be controlled by site management following the manufacturer’s instructions.
4. Rubber gaskets should be kept clean and away from oil, grease, excessive heat, and the direct rays of the sun.
5. Pipes are to be checked on unloading. Damaged and defective pipes shall not be used at the site. The pipe shall be re-inspected just prior to installation. Possible damages are reported on the delivery note.
6. Pipes or fittings will not be drop or drag.
7. Ensure that the material is stored in the shaded area to protect it from exposure to direct sunlight.
8. Leave sufficient space between individual pipes.
9. The storage area shall be cleaned and is at an appropriate height from the ground level. Separate areas in the storage zone must be marked for different materials.
10. Whenever heavy or bulky material is to be moved, the material handling needs will be evaluated in terms of weight, size, distance, and path of movement.

Material Inspection

For materials to be inspected after receiving at the site, the following points are to be followed:

Each material item shall be allotted a distinct and separate reference number and mentioned on the material requisition. Make sure that material is approved/examined by the consultant and QA/QC and associated documents/test certificates are approved.

• The store in-charge shall ensure that all approved supplies be delivered to the site as per the approved material submittal; with the manufacturer’s seals, labels, or other proof of origin intact. These labels and seals shall not be removed until the material is required for use and shall be retained for inspection by the consultant and QA/QC.
• The store in-charge shall initiate material inspection for all incoming material to QA/QC and the material shall be inspected against reference documents and as per approved material submittal. Moreover, the physical condition of the material shall be checked. Afterward, an INR shall be raised by QA/QC to the consultant and an inspection will be carried out by the consultant.
• Materials that do not conform to the given specification/approved material submittal, shall be rejected. Any discrepancy or damages will be notified and reported for further action.
• For any materials inspection (especially pipes, fittings, other accessories), the items shall be segregated as per their type/sizes and placed items separately in racks or on different pallets.
• Each rack/pallet shall have an identification posted on a laminated paper with the description of the items clearly written on it.
• There shall be appropriate spaces between the pallets so that the engineer/inspector can freely go around them and inspect the materials thoroughly.
• Staking the materials all over each other & in one corner is strictly not allowed.

Resources

A. Tools and Equipment

The job will be carried out by manual means. The following are the types of tools identified for works:

• Measuring Tape.
• Pipe cutter
• Marker
• Copper soldering unit
• Copper threading tool
• Jointing Torch
• Scaffolding and ladder
• Plumber standard toolbox kit.
• PPE (Hand gloves, face masks, safety goggles)
• Safety harness (for high-level work)

All testing equipment and measuring tools to be used shall have a valid calibration certificate prior to usage.
All lifting equipment and machines shall be 3rd party verified with valid certificates

B. Materials

Material includes but is not limited to the following.
• Copper tubes and fitting as per BSEN 1057, class X
• Approved copper pipes and fittings for Hot and Cold water supply.
• ERW sleeves
• Pipe support

Item Description:
Copper pipes: size range from 15 dia. to 159 dia. mm
Fittings: size range from 15 dia. to 67 dia. mm
Fittings: Size range above 67 dia. mm

Brazing and soldering
a. The material shall be used after being approved through Material Submittals.
b. All material to be used shall conform to the project specification and authorities’ regulations (where required).

C. List of Manpower

• Construction Manager
• Site Engineer
• QA/QC Engineer
• HSE Officer
• Supervisor
• Foreman
• Pipefitters/Installers
• Surveyor
• Helpers
• Forklift Operator
• Certified welders

Note: Certificate shall be presented at the time of commencing installation.

Mobilization

A. Preparation and Planning

Precautions, manpower, and equipment are available before the commencement of work. The Site Team shall make sure that access roads are always clear from any obstruction and the site is always accessible.

B. Site clearance

Before commencing the work, the area shall be cleared of all debris, materials, or other obstructions.

C. Traffic Management

The Site Team with the assistance of the Safety Officers shall coordinate logistics and materials movement through the site following the direction and road signs displayed on site. The required diversion routes shall be marked on drawings including the required traffic signs.

The Work Permits and Operator Certificates shall be compiled and files for reference by authorized personnel.

Temporary traffic signs, barriers, and flagmen will be deployed to control traffic flow in accordance with and Traffic Management of the HSE Plan.

At the end of each ramp, there will be a transition area to give the driver the opportunity to watch the access roads before joining thereto.

D. Pre-construction Safety Meetings:

The meeting shall be scheduled prior to the beginning of the work and before any Subcontractor starts on the project.

Safety awareness meetings will be conducted every working day morning/every other day to brief the workforce on the safety prevention measures. The equipment check for safety shall be recorded/ documented during the daily Safety Awareness Meeting.

Traffic safety will be discussed to emphasize these meetings.

Each worker will be instructed to follow specific safety requirements related to his trade. They will be required to follow installed safety signs, observe barricades and use PPEs. The safety team will perform hazard risk analysis by identifying all steps, hazards identified in those steps, with a focus on the relationship between the work task, the tools, and the work environment. After identifying uncontrolled hazards; The contractor will take steps to eliminate or reduce them to an acceptable risk level.

General Contractual Safety, Health, and Environmental requirements:

Roles of the contractor, subcontractors, authorized representatives, and all project workers.
Accident reporting requirements.
Specific details of the work to be performed along with the use of personal protective equipment.
Emergency procedure.

E. Operating Procedures:

A site investigation has to be carried out to develop safety precautions and measures prior to the commencement of the work. After such investigation, relevant signboards will be displayed and barricades will be installed where and as necessary, such as but not limited to the following:

Relevant information, advanced signs, warning, and mandatory signs will be placed as required.
A radio communication system would be used where normal communication is impossible.
After completion of the work, safety cones and barricades have to be removed accordingly.

Methodology-Hot and cold water copper piping installation

The below methodology is based on the manufacturer’s method statement which is included in the approved material transmittal:

Supervisor/Foreman will carry out the marking routing of copper pipe for hot and cold water supply pipes as per approved drawings. If there is any discrepancy or difficulty in executing the work, it is to bring to the notice of the Engineer for corrective action.

Cutting and chasing of pockets for copper pipes, to be done by means of the cutter. If a hacksaw is used to cut the pipe, a fine-toothed blade shall be used.

Jointing of copper pipes; Clean the outside surface of the pipe and inside surface of the fitting socket, the reliability of the soldered joint is influenced by the type of flux used. Yorkshire flux and traditional craftsman flux are specially formulated for jointing copper pipes with Yorkshire integral solder ring fitting.

Insert the pipe into the fitting until it reaches the pipe stop, then wipe off any excess flux. Then heat the assembled joint until a complete ring of solder appears at the mouth of the fittings.

After jointing allows the joint to cool without disturbance, clean the joint generally, wiping off any external flux residues, this will prevent unsightly stains or corrosion of pipework.

Threaded connection; jointing washer should be used when installing fittings with parallel connector thread, a male thread connector a small quantity of inert jointing compound or PTFE tape should be applied to the male thread before installing the fittings. As per the manufacturer’s recommendation, the jointing compound should comply with
BS 6956 Part 5 and be WRAS listed. PTFE tape for water and general application should comply with BS 7786.

The copper pipes and fittings for hot and cold water supply to be assembled in position using the torch.

The assembled copper hot and cold water supply pipes and fitting assembly are to be placed in position by means of a clamp and supports at a specified interval and at the change of direction. The hydro test will be done in coordination with the consultant prior to starting the wall packing.

The entire assembly is to be tested with a head of 1.5 times the working pressure of the system.

Due care to be taken to ensure that the level of the hot and cold water pipes assembly is not disturbed during packing, plastering, and tiling, and contractors representative will ensure, throughout the mortar packing process, that no pipes get damaged.

In case of the hot and cold water pipes assembly is running expose above the false ceiling or on the roof, the copper pipe will be used and proper access for maintenance is to be provided.

Cut tube square

Cut to the exact length required using a tube cutter or hacksaw If a hacksaw is used, a sawing fixture should be used to ensure square cuts. Remove all inside and outside burrs with a reamer, file, or other sharp-edge scraping tool. If the tube is out of round it should be brought to true dimension and roundness with a sizing tool.

Clean tube end and inside surface of the fitting

The joint surface areas should be clean and free from oil, or oxide contamination. Surfaces may be properly cleaned for brazing by brushing with a stainless steel wire brush or by a stiff rubbing with an emery cloth.

If oil or grease is present clean it with a commercial solvent. Remember to remove small foreign particles such as emery dust, by wiping them with a clean dry cloth. The joint surface must be clean.

Select brazing alloy

Brazing filler metal selection. When brazing copper to copper, alloys such as Dynaflow, stay-silv®, or stay-silv® 15 are recommended. These alloys contain phosphorus and are self-fluxing on copper. When brazing brush or bronze fittings, stay-silv® white flux is required with these alloys.

When brazing iron, steel, or other ferrous metals, select one of the safety-silv® Brazing alloys such as safety-silv®45 or safety-slv®56 with stay-silv® with flux. Do not use phosphorus-bearing alloys as the joint may be brittle.

Perform proper fluxing

Proper fluxing is important because the flux absorbs oxides formed during heating and promotes the flow of the filler metal. When using Stay-silv® while flux applies it only with a brush. To prevent excess flux residue inside refrigeration lines, apply a thin layer of flux to only the male tubing.

Insert the tube into the fitting and, if possible, rotate the fitting once or twice on the tube to ensure uniform coverage.

Flux application

While flux is used for most applications. Black flux is helpful for long heating cycles or localized heating with induction. It is also used when brazing stainless steel.

Flux goes through physical changes during heating and turns clear at about 1100°F/593°C. This is an indication that parts are close to the brazing temperature. Stir Flux before use. If the flux is dried out add a small amount of water unit flux reaches a paste consistency

Adjust torch flame

Oxygen/acetylene- For most brazing jobs using oxy-acetylene gases, a slightly carburizing or neutral flame should be used. The neutral flame has a well-defined inner core. Avoid an oxidizing flame.

Air/acetylene using inferno® swirl Combustion Tips-Brazing with air/acetylene is a popular alternative to oxygen-mixed fuel gas. The fuel gas flow aspirates air into a mixer that contains an internal vane that spins the gas to improve combustion and increase flame temperature.

If the tank has a delivery pressure gauge, set the delivery pressure to 14-15 psi. If the tank has only a contents gauge delivery pressure is preset at the factory. Open the regulator adjusting screw all the way by turning it clockwise until it bottoms.

Open the torch valve-opening the torch valve for about ¾ of a turn will provide sufficient fuel gas delivery. Do not try to meter pressure (reducing the flame) by using the torch handle valve. If a higher or lower flame is required, change to a different tip size.

Other fuel gases-alternate fuel gases such as propane, propylene, and neutral gas can be mixed with oxygen for brazing. Refer to the Harris equipment catalog or website for equipment and setting information.

Heating the joint

Always keep the torch in short motion.

Start heating the tube, by first applying the flame to a point just adjacent to the fitting.

Work the flame alternately around the tube and fitting until both reach brazing temperature, before applying the brazing filler metal.

When the flux is used. it will be a good temperature guide. Continue heating the tube until the flux passes the “bubbling” temperature range and becomes quiet, completely fluid, and transparent. Watch for this on both sides of the joint to ensure even heating

Direct the flame from the tube to the fitting. When the alloy is applied it should quickly melt and flow into the joint.

Sweep the flame back and forth along the axis of the assembled joint, tube, and fitting to reach and then maintain uniform heat in both parts.

Apply the brazing alloy

Feed the alloy into the joint between the tube and the fitting. Only after the base metals have been heated to brazing temperatures should the filler metal be added. At the time flame may be deflected momentarily to the tip of the filler metal to begin the melting process.

Always keep both the fitting and the tube heated by playing the flame over the tube and the fitting as the brazing alloy is drawn into the joint. The brazing alloy will diffuse into and completely fill all joint areas.

Do not continue feeding brazing alloy after the joint area is filled. Excess fillets do not improve the quality of the dependability of the braze and are a waste of material.

Making vertical alloy up joints

Heat the tube first, then apply heat to the fitting. It is important to bring both pieces up to temperature evenly. Keep the flame directed towards the fitting. If the tube is overheated, the brazing alloy may run down the tube rather than into the joint.

Clean after brazing

All flux residue must be removed for inspection and pressure testing immediately after the brazing alloy has set quench or apply a wet brush or swab to crack and remove the flux residue. Use an emery cloth or a wire brush, if necessary.

Separate a brazing joint

First, clean the joint thoroughly, then flux the visible alloy and all adjacent areas of the tube and fittings. Next, heat the joint (tube and fittings) evenly, especially the flange of the fitting. When brazing alloy becomes fluid throughout the joint area, the tube can be easily removed. To re-braze, the joint, clean the tube end and the inside of the fitting
and proceed as directed to make a new brazed joint.

Nitrogen purge

During braze heating, an oxide scale forms on the inside of the copper tube. These dark scales flake off and are carried by refrigerant and can potentially clog small orifices.

For HVAC/R and medical gas, installations flow nitrogen through the tube during brazing to prevent internal scale information. Use a low flow rate to avoid excess pressure inside the tube. A small hole at the line end will allow the nitrogen to escape.

Pipe penetrating the walls and slab

Where pipe passes through floor, slabs, walls, the roof, or penetrate any other form of construction, pipe sleeve shall be supplied and accurately placed in the building surface. The pipe sleeve shall be sized to provide 15 mm clearance around the pipe to be installed or, where the pipe is to be thermally insulated or otherwise covered, 15 mm clearance around the covering surface. This clearance space shall be packed with approved fire resisting material and sealed at both ends with waterproof and fire retardant mastic.

Sleeves shall be of material compatible with the pipe and of length to finish flush with the finished wall and were passing through floors of length to protrude 6mm above and below the finished floor and the underside level (soffit).

Roof sleeves shall be provided with water-shedding external cowls and flashing.

Water-protecting pipe sleeves through floors shall be supplied and fixed in the following location:
In mechanical plant rooms
In kitchen areas, toilets and cleaners’ rooms
In slabs over mechanical and electrical plant rooms
On all floors have a waterproof membrane

The pipe sleeves shall be galvanized mild steel pipe set to extend for the full thickness of the structural element and 50mm minimum above the finished level.

Wall and floor plates:

Where pipe penetrates walls, floors, or ceilings, (except at plant, equipment, and cleaners rooms or other storage areas) split type chromium-plated steel wall plates shall be fixed to closely fit the building surface and provide a neat appearance.

Supports and hangers

All supports system shall be of the correct size, and strength and allow for expansion, contraction, and anchoring of the piping systems. Full details of hangers and supports proposed for use shall be submitted before fixing commences.

Vertical drop shall be properly restrained and supported to prevent offset and sway. Piping at all equipment and valve positions, and at main junctions, shall be adequately supported to prevent any distortion or transmission of the train to connected equipment or valves.

Brackets and supports shall be so arranged and set out to allow sufficient access for adjustment, maintenance, and removal of equipment, valves, and accessories with the minimum of dismantling and without the need for additional temporary supports after items are removed.

A proprietary support system for all pipework may be used to achieve technical and visual compatibility of supports subject to acceptance by the Engineer.

Piping shall be supported by the use of rollers and chairs, guides, clips, or hangers fixed at intervals scheduled. Where two or more pipes are to be carried out by a single support, the support spacing shall be for the shorter interval.

All mild steel sections, plates, clamps, and fixing devices for fastening hangers and supports shall be provided by the contractor.

Hangers for cold piping required to be thermally insulated shall be provided with high-density foam insulation (reinforced where necessary) bearing inserts capable of withstanding the clamp compression and allowing the hanger to support the pipe without metal-to-metal contact.

Insert shall be of the same thickness as the thermal insulation required and valve extended cylindrical insulation shield of galvanized sheet steel or glass fiber reinforced plastic of not less than 2mm thickness with adequately sealed joints to maintain vapor barrier where applied.

Support and hangers for mild steel piping shall be ferrous. Supports and hangers for copper piping shall be non-ferrous, or alternatively may be ferrous with an insert separation liner to prevent electrolytic action. Supports and hangers for chromium-plated or stainless steel piping shall be chromium-plated.

Spacing for piping support shall be as follows:

Table for Support Distance

Pipe Rod Sizes

Health, Safety, and Environment

I. Risk Assessment:

Risk Assessment/Job Hazard analysis as provided/attached in the method statement for water piping copper (hot and cold) installation.

II. Protective and Safety Equipment

All workers involved shall be equipped with adequate PPE as stated below:

• Safety helmet with company logo
• Safety boots, safety goggles, hand gloves
• High visibility vest
• Welding specific PPE (Welding vest, mask, gloves, visor)
• Twin tail harness, max 1 m long (when working on height)

All special PPE (Harness) is considered as a last resort when it cannot engineer, administratively eliminate, or guard against hazards.

III. Information to Personnel
• Safety Induction
• Job Training
• Superintendents
• Notices/Memos
• Toolbox Talks
• Briefings before starting work

IV. Emergency Procedures :

The contractor shall provide first aid kits on site for handling light injuries.

In the event of an emergency, all workers will be asked to evacuate and assemble at the “ASSEMBLY POINT” and wait for further instruction from supervisors.

Quality Assurance and Quality Control for Method Statement for Water Piping Copper (Hot and Cold)

a. Quality Assurance Requirements

The contractor shall provide the required documents for the consultant’s approval prior to initiating the execution of this activity as per project specification.

The quality control requirement shall include related QCP’s, ITP’s and other related documents as applicable.

Applicable codes and standards for materials are project specifications and contract requirements.

Quality Assurance Process

The contractor shall notify the engineer prior to the start of the activity and comments from the site Instruction will be complied with the satisfaction of the consultant.

Follow up and Evaluation

Follow up on quality performance shall be carried out through an in-house monitoring system such as progress reporting to the planning department, daily, weekly and monthly reports generated by the planning department to closely
monitor site performance in general and reflect on quality performance in specific.

All the above shall be conducted in close coordination with the quality department to monitor any deviations from the normal quality requirement and induce corrective actions whenever required to eliminate non-conformance or
quality deviations.

All remedial actions to be taken, if any, shall take into account the official schedule which is to be used as a guideline for performance and most importantly under the close supervision of the quality control department.

Records

• Checklists (CL)
• Inspection Request (INR)
• Inspection and Test Record (ITR)