Method of Statement For Cast-in Pipeworks (Mild Steel or Ductile Iron)

This pipeworks procedure is applied to all the cast-in pipeworks (mild steel or ductile iron) for the project site in water treatment facility.

The contents or procedures provided in this document are based on the general good water industry practices and manufacturer standard recommendation.

The installation work contractor shall follow this procedures strictly unless otherwise instructed by the manufacturer, Client or Project’s Consultant.

The document will cover the complete items and procedures for the above works and is divided and described into six (6) main sections:

• contractor’s work scope,
• the material provided by the contractor or Client on behalf,
• the equipment/tools/machinery/ chemicals and any other consumables used to execute the works,
• workforce plan or workers allocation for the works,
• the detail work sequence or procedures,
• and the safety measures adopted by the contractor throughout the entire pipeworks.

The materials to be used for the above work are listed below:

• DN150-750mm MSCL and DICL straight puddle flange pipes (plain or flange ended.
• Mechanical coupling, collar joint, flange adapter as applicable.

Tools / Machinery / Consumables

• Complete tightening tools
• Oxy acetylene cutter
• Level gauge & measurement tape
• Arc welding set & electrodes
• Grinding machine
• Chain block
• Hydraulic jack
• Standard rubber gaskets
• Finishing paint and consumables
• Mobile crane or crane truck if applicable

Basic Safety Measures

The workers shall be equipped with the following PPE throughout the work at site:

• Gloves
• Safety helmet
• Goggles for welding operation
• Safety shoes

The working area shall be barricaded and sealed with red/white warning stripe throughout the pipe installation. Health and safety risk assessment shall be completed and implemented throughout the project duration.

Procedure For Pipeworks (Mild Steel or Ductile Iron)

General Requirements:

Obtain permission/instruction to start work from the Client or project site engineer.

Brief on work safety and possible risk(s) and scope of works before start of work.

Identify the fittings, equipment and components, and location for installation as per the approved drawing.

Check that power supply, tools, consumables, and machinery for the installation work are in place.

Ensure mobile crane/truck is available and on site.

Make sure that accessibility and clearance at installation location i.e. clear of blockages, clean and safe for working.

Follow the submitted installation guidelines from pipe manufacturers.

Cast-In Pipework Installation Procedure

Prepare the cast-in pipe with the puddle flange facing the wall side to be inserted in i.e. clean from dirt, mud, etc.

Measure and determine the invert level of the cast-in pipe required. Measurement should be taken from the invert level of the pipe and not the bottom edge of the puddle flange.

The reinforcement steel bar shall be bent accordingly for the pipe seating with temporary timber support at one side.

Coordinate with the contractor site engineer to determine the wall thickness and tank internal wall position in order to measure the puddle flange distance from the internal wall line.

Ensure that the cast-in pipe has sufficient clearance from the FGL in case of above ground installation for the bolting or jointing requirement.

The cast-in piece shall be inserted or put into the wall in line with the reinforcement steel work and before the form work. The puddle flange must be in between the reinforcement bars as shown in the installation guideline.

Once the cast-in pipe is levelled as required. The pipe body is to be tap-welded to the bent reinforcement bars to set in place.

Ensure that temporary support timber are sufficient and steady to support the set-in pipe.

Site engineer to inspect the set-up after the cast-in pipe is set into place before the form work.

The form work can be set after the cast-in pipe is in place and ready for concreting. Attention shall be made during concreting to ensure the bottom area of the cast-in pipe is fully filled with concrete to prevent voids or air pocket formation.

For final physical inspection, client/site engineer to witness and sign off the work check sheets upon inspection.