METHOD STATEMENT FOR INSTALLATION & INSULATION OF DUCTWORK

TABLE OF CONTENTS

1. Scope / Objective

• Reference

• Access / Egress

• Health and Safety Hazards
  • Safety Lighting
  • Task Lighting
  • Emergency Arrangements
    • General
    • Fire Precautions
    • Communication
  • Risks Control
• Hazards / Risks
• Control Measures / Permits
• 3^rd Party Protection
• Environmental Considerations

• Definitions

• Responsibilities / Supervision

• Procedures / Method to be Employed

• Training

• Working Hours

1. House Keeping

1. Manpower Requirement & Supervision

1. Material Requirement

1. Plant & Equipment
   1. General
   1. Plant and Equipment Schedule
   1. Personnel Protective Equipment
   1. Power
   1. Working Platforms

1. Q.C. Approvals and other Documentation

1. Supporting Documentation

1. Distribution

1. Other Information

1. Site Safety Engineers Approval

1. Attachment – Sketches

1.0     SCOPE / OBJECTIVES

This Method Statement covers the installation and insulation of ductwork. This procedure defines the method used to ensure the ductwork installation and insulation has been carried out as per contract requirements and best commercial practices.

• REFERENCES

Contract document: 1105/SP/M-15100   Basic Materials and Methods

                              1105/SP/M-15321   Sheet Metal Ductwork and                         Specialties

                              1105/SP/M-15341   Thermal and Acoustic Insulation

Technical submittals:  HVAC/30   Access Doors

                                 HVAC/18   Fire Dampers

                                 HVAC/09   Grilles and Diffusers

                                 HVAC/17   Volume Control Dampers

                                 HVAC/01   G.I. Sheets

                                 HVAC/19   G.I. Ductwork

                                 HVAC/42   Supports

                                 HVAC/37   Flexible Duct Connectors

                                 HVAC/47   Foam Sealant

Standards:              DW/144 Specification for Sheet Metal Ductwork

                              SMACNA – HVAC Duct Construction Standards

Shop Drawings – Marked APPROVED FOR CONSTRUCTION

The Shop Drawings and Pipework Details should provide enough details for the installation to be carried out. For installation contract documents, manufacturer’s instructions and relevant standards shall be followed as applicable. In the absence of any information on the drawings the above documents should be referred to in the order shown.

• ACCESS / EGRESS

Work will be carried out only when all associated works of the main contractor have been verified that they have been completed.

4.0     HEALTH AND SAFETY HAZARDS.

Implementation of Health & Safety mechanisms and checks as per Contract Agreement and the approved A&P Health & Safety Manual. The responsible Safety Officer for each building will conduct routine safety inspections.

1. Safety Lighting.

     Safety lights will be used in case of power failure ensuring good illumination of the area for evacuating.

• Task Lighting.

Adequate lighting will be provided ensuring the good illumination of the working area. Task lighting will be connected to the nearest site distribution board which is RCD protected.

• Emergency Arrangements.

• General: Site general safety procedures will be followed. In case of emergency the Safety Officer will stop the work. He will put into action the emergency arrangements and report to assembly points as indicated during the Site Induction Course.

• Fire Precautions: No significant fire risk is associated with this activity but general fire prevention measures will be taken as per Arabtec instructions to A&P.

• Communication: Communication from work areas to Site Office shall be via mobile phones issued to Senior foremen. In emergency situations use hand-held 2-way radios if necessary to speed up notification of relevant personnel and/or the JBR01 Site Clinic.

• Risk and Controls.

• Hazards / Risks

          Relevant Risk Assessments (See Section 19 Attachments):

                   1.     PRT – 006 Disc Cutters & Abrasive Wheels

                   2.     PRT – 007 Hand Tools

                   3.     WAH – 001 Ladders and Stepladders

                   4.     WAH – 002 Mobile Elevated Working Platforms

                   5.     WAH – 006 Working at Heights

                   6.     MAT – 004 Disposal of Waste Materials

• 3^rd Party Protection: Applicable as per the contract only

• Environmental Considerations: After the finalization of the works the working area should be cleaned from any scrap materials related to the performed work.

5.0     DEFINITIONS

                       As to specifications (see References).

6.0     RESPONSIBILITIES / SUPERVISION

• Project Manager – will have the overall responsibility of the Project for execution, quality and safety. Also he will maintain the planning progress and coordination of works with main contractor.

• Project Senior Mechanical Engineers / Site Mechanical Engineers – will be responsible for the day to day activities on site, for materials, drawings, testing & commissioning and allocation of Departmental resources to work areas on Site. The Project Senior Mechanical Engineer will report to the Project Manager.

• Supervisor – will be directly responsible for the day-to-day job on site, for coordinating work with the technicians or any other staff assign to his area.

• QA/QC Department – will be overseeing the quality requirements and quality control measures for the Project in coordination with the Senior Project Mechanical Engineer as outlined in the A&P QA Manual.

• Safety Officer – will be responsible for the Health and Safety aspects on site as per the Mains Contractor and A&P Safety requirements.

• PROCEDURES / METHOD TO BE EMPLOYED.

• Pre – Ordering:

       Drawings must be prepared and approved.

• Ordering:

       Follow standard A&P procedures for ordering of ducting.

• Factory manufacture.

       As per Supplier/Manufacturer

• Transportation to site:

By supplier. Ensure the ductwork is protected from weather elements during transportation.

7.5     Inspection of Materials in Stores

7.5.1   Upon receipt of materials on site these will have to be inspected by the Storeman and Site Engineer or representative, to ensure correctness of materials and quantities.

7.5.2   A Material Inspection Request (MIR) shall be issued and all materials must be inspected and verified by the Engineer that they are correct.

7.6      Pre Installation Checks

7.6.1   Before any materials are installed ensure that these have been inspected at site and have been approved as per the relevant MIR form.

7.6.2   Ensure that all drawings are current and marked “APPROVED FOR CONSTRUCTION”.

7.6.3   Inspect the site and ensure that all necessary sleeves and openings have been allowed for.

7.6.4   Inspect the relevant area for any possible clashes with other services.

7.6.5   Inspect all materials and verify that they are undamaged.

7.7     Installation

          7.7.1   Marking

Mark from approved drawings the position of all ducting on a floor or section as is possible by the programme / related progress on site (i.e. ATC)

       7.7.2   Marking of Supports

Support Spacing shall be as per the table below (Table 1. Support Spacing).

Table 1. Support Spacing.

       7.7.3   Installation of Supports

Attachments to the roof slab will be by the means of expansion anchors. Drill into the concrete and place the expansion anchor.

Threaded rods and channel sections will be prepared for installation in the workshop or in situ.

Projection of a rod through the bottom bearer should, where practicable, not exceed twice the thickness of the securing nut.

                 See Figures below for further information.

Threaded Rod, Channel and Expansion Anchor Details

       7.7.4   Checking of Ductwork Before Assembly

Check that all the ductwork is tagged and that the correctly tagged sections are available for the job.

Randomly check that the ducting is made to the correct thicknesses (1 in 10 sections).

Tolerances will be based on the following table (Table 2.) extracted from ASTM A924/924M-94, Standard Specification for General Requirements for Sheet Steel, Metallic Coated by the Hot – Dip Processes (Formerly ASTM A525); and ASTM A653/A653M-94, Standard Specification for Sheet Steel Zinc – Coated (galvanized) or Zinc – Iron Alloy Coated (galvanized) by the Hot – Dip Process.

Table 2. Acceptable Tolerances.

Check dimensions are correct. Where dimensions are shown on the drawing these are internal dimensions.

Dimensional tolerances are ±2 mm

Check that the duct sections and fittings are free from any defects.

Check that the ducting is clean. Clean if necessary.

                           7.7.5   Assembly of Ductwork on the Work Bench

Assemble ducting into 2.4 meter lengths and any necessary end fittings. Ensure that the correct type of joint is used i.e. proprietary flange or slip joint. Seal joint using an approved sealant (e.g. Foster 30-45). (see Table 3. (as per DW/144).

Table 3

7.8   Insulation of Ductwork

Insulate ducting as follows:

       7.8.1   External to Ductwork

        7.8.1.1 Straight sections of duct.

.1      Clean the duct and make sure dust, oil and grease etc. is removed from the surface where the insulation is to be applied.

.2      Fix self adhesive stuck – up pins at 300 mm centers at bottom of the ducts. Position pins leaving 100 mm from the joints and corners of the duct.

.3      Apply full coat of Adhesive Foster 81 – 10 on the duct surface.

.4      Cut the insulation board lengthwise sufficiently covering the total area plus an allowance for a 50 mm overlap at one end. (Board is supplied in size 1200 x 2000 mm long)

.5      Mark the duct size on gloss side of the board – not on facing side – and make “V” groove to match the fix sized corners of the duct.

.6      Fix the insulation already cut to the size of duct to the substrate. Ensure that the corners are formed ninety degrees without leaving a gap in between the insulation and substrate.

.7      Place the overlap in place and fix to the adjacent surface using adhesive. Make sure the adhesive is used just for the purpose not lavishly.

.8      Wipe any wet – spilled out – adhesive from the surface by means of dry cloth.

.9      Apply Aluglass – self adhesive aluminum foil laminated glass fabric tape 75 mm wide for insulation thickness of 25mm and 100 mm wide for 50 mm insulation.

.10    Press the tape to the substrate uniformly using any smooth edged plastic card and make sure no wrinkles are formed. This is to ensure that no air passage within bond is formed, which can weaken the system.

.11    Reinforce the longitudinal and transverse tape joint by fixing 200 mm long tape strips at every 300 centers in transverse direction to the main tape joints.

7.8.1.2 Duct to Duct with Proprietary Flange Joints or Angles – Fire       Dampers, VCD’s etc.

.1      Insulate the straight ducts on either side of the flanges.

.2      Cut 100 mm wide insulation bands having 75 mm wide overlap (when insulation thickness is 25 mm).

.3      Fix the above band in the centre of the flange joints using full coat of Foster 81 – 10 adhesive on the substrate.

.4      Apply adhesive lightly on the overlap and fix the overlap to the tape surface taking right fold – say 90 degrees from top at the neck of joint. This way you get 50 mm overlap affixed to base surface of duct. Make sure the corners of overlap are cut and fixed in such a way that no vapour barrier break is allowed

.5      Seal the joints by fixing Aluglass tape over the overlap turned down to the base insulation surface, centrally between overlap and then substrate.

7.8.1.3 Flexible Joints and Ducts in Shafts

.1  Flexible joints need more care as vibration may loosen the tapes

.2  Follow the steps outlined above using 100 mm Aluglass tape on overlaps already glued over the face of the FCU and apply two coats of Fenomastic gold paint over the joint.

7.9  Lifting and Installing

Lift ducting up carefully and install as necessary. Connect to previous section if applicable taking care to seal the joint with duct sealant.

Tighten all nuts and bolts, check that inserts are in position.

7.10 Connections to Equipment

Cut a length of flexible equal to 1.5 times the perimeter of the ductwork. The flexible shall be as per Approved Technical Submittal (i.e. Dyne or Exelon). Check that the box and the model number referred to here are the same.

Pop – rivet as necessary in centres of 100 mm.

Seal using duct sealant as necessary.

Ensure that the equipment and the ductwork are aligned. A maximum misalignment of 30 mm is permitted.

7.11 Final Air Terminal Connections

7.11.1 Air Diffusers

7.11.1.2 Air diffusers in T – bar ceilings

The ceiling tile is first cut to size by the Main Contractor. The ceiling tile is reinforced using 5 mm plywood by the main Contractor.

Install the flexible ducting ensuring that no sharp bends or excessive flexible duct will remain.

Clamp the flexible ducting using approved clamps.

Install the diffuser by pop riveting the diffuser on cross supports installed on the tile.

7.11.1.3 Air Diffusers in Plasterboard Ceilings

The solid spigot is dropped to ceiling level.

An angle iron is installed in the spigot.

The diffuser is installed last.

Ensure that the diffuser fits snugly in the ducting.

Seal as necessary

7.11.2    Grilles and Louvers

Install as per manufacturers recommendations and as per specifications.

7.12 Electrical Bonding

Metallic ductwork systems will be bonded in accordance with BS 7671: Requirements for Electrical Installations (The IEE Wiring Regulations 16^th Edition.).

7.13 Checking up for Correctness of Installation

Once section is complete check against Inspection Checklist

(Document No.: M-3.0.01.CS01 & M-3.0.01.CS02).

Rectify any defects as necessary.

The following figures show the correct installation method.

Correct Installation Methods

• TRAINING

8.1  Tradesmen performing the described work will be experienced duct erectors / insulators. If deemed necessary specific team / individuals will undergo further training and awareness programs for this activity by the Production / Quality Assistance Departments.

• Toolbox talks will provide general training and awareness for each activity and also in Health & Safety matters and precautions.

• WORKING HOURS

Normal working hours: 7.00 am to 5.00 pm

1. HOUSE KEEPING

          All work places where A&P personnel are working will be cleaned from the scrap materials derived from their work ensuring clean and healthy work environment as well as to maintain free access and egress in the event of emergency.

1. MANPOWER REQUIREMENT & SUPERVISION

Manpower requirement & supervision depends upon the planning organization chart and site progress of works.

1. MATERIAL REQUIREMENT

1.      Ducting

2.      Duct Sealant

3.      Gaskets

4.      KIMMCO KDIP (RIGID BOARD)

5.      Foster 81 – 10 Adhesive

6.      Stuck up Pins (Self adhesive)

7.      Aluglass Aluminium tape:    75 mm

                                                  100 mm

8.      Fenomastic Gold Paint

9.      Pop rivets

10.    Insulating board

11.    Threaded Rod:     8 mm

                                   10 mm

12.    Nuts and washers:    8 mm

                                        10 mm

13.    UNISTRUT Channel, 40 x 10 x 2.5 (mm)

14.    Expansion Anchors:  8 mm

                                        10 mm

1. PLANT & EQUIPMENT REQUIREMENTS

1.      Duct Erector’s Tool box

2.      Duct Insulator’s Tool box

Personnel Protective equipment:  All personnel should wear at all time safety shoes, helmet and coverall.

1.    Working Platforms: Scaffolding as required within the specific work area.

1. Q. C.  APPROVAL AND OTHER DOCUMENTATION

1. SUPPORTING DOCUMENTATION

Shop drawings.

1. DISTRIBUTION

• Main contractor,
  • Project Senior Mechanical Engineer
  • Q.C. Engineer
  • Site Mechanical Engineer
  • Tower Health & Safety Officer

1. OTHER INFORMATION

No applicable

1. SITE SAFETY ENGINEER’S APPROVAL

Risk mitigation measures as identified in Risk Assessments in Section 19 to be inspected at regular intervals for Activity duration as identified in the approved Health & Safety Manual.

1. ATTACHMENTS

Quality Control Checklists:

                 Ductwork Installation Quality Control Checklist

                 Ductwork Insulation Quality Control Checklist

       Risk Assessment Forms:

                 PRT – 006 Disc Cutters & Abrasive Wheels

                 PRT – 007 Hand Tools

                 WAH – 001 Ladders and Stepladders

                 WAH – 002 Mobile Elevated Working Platforms

                 WAH – 006 Working at Heights

                 MAT – 004 Disposal of Waste Materials