Piping Work Method For Fuel Oil Pipe Fabrication Installation and Testing

The scope of this document is to describe the basic methods which shall be adopted for installation and testing of Fuel Oil Piping (ASME B31.9,”Building Services Piping”).

This document also details the tools & tackles, manpower and Inspection and Test plans, to meet the requirements of applicable codes and client’s project specifications for pipe fabrication works.

The activity includes transporting pipes and fittings to site, Fabrication, welding, NDE & Pneumatic testing of piping as per the project specifications and approved  drawings  for the Fuel Oil System.

Scope of works includes horizontal and vertical installations of pipelines through all the areas in the project and buried underground lines in the infrastructure area as per Fuel Oil System distributions as per the specifications and shop drawings approvals.

Roles & Responsibilities

Project manager shall be responsible overall to complete all MEP works as per specifications, budget, time and quality.

MEP Site Engineers shall be responsible for but not limited to the following important activities:

Coordinate with the civil team for any area preparation, access, clearance.

Ensure that all the preparation and application works are carried out according to the contract specification and manufacturer’s data sheet(s).

To ensure that the progressing of works is carried out according to the planned program, and as per the approved method statements.

Make sure that all the equipment’s and materials required in executing the works are available according to the planned construction program.

Coordinate with the main contractor’s MEP coordinator and safety officer for all safe and proper execution of the work in accordance with the risk assessment.

Site Mechanical Engineer will ensure proper handling of materials at all stages of fabrication, erection & testing. All pipes are fixed with end caps closed until it is ready for fabrication/installation to avoid sediments going inside.

Foreman shall be responsible for but not limited to the following important activities:

To guide and control the tradesmen and charge hands.

Ensure that work is done as per the approved shop drawing(s).

Report to the MEP site / project engineers.

To arrange daily workshops.

Health & Safety Officer shall be responsible for but not limited to the following important activities:

• Ensure health and safety of the site personnel.
• Ensuring PPE available with site personnel
• Good housekeeping on site
• Environmental concerns are addressed.
• Responsible for implementation and assurance of the safety and environmental requirements (JSEA).

Quality control QA/QC engineers shall be responsible for but not limited to the following important activities:

• Raise MIR for pipes, fittings & equipment for Consultant approval when it is delivered on site.
• Inspecting the materials on site as per approved materials submittal prior to installation on site.
• Inspection for the installation as per approved drawings and approved test plans and checklists.
• Preparing test forms for testing on site and updating the outcomes/results
• Issuing inspection request within 24 hrs before the actual inspection, after completion of work.
• Responsible for the assurance of Quality control, method statement and inspection test plan.
• Controlling the shop drawings flow on site.

Applicable References Codes & Standards

• Shop drawings
• Inspection and Test
• Project Health & Safety HSE Plan
• Project Quality Plan
• Project Logistics
• NFPA 30, 30A, 31 & 100.
• UL 142- Steel Above Ground Tank for Flammable and combustible liquids
• UL 1746 – Double wall steel- Fiber glass Underground Storage Tank
• UL 2084- Rectangle Secondarily Contained Above Ground Tank
• IEC – 600034, 600072 – Rotating Equipment’s standards and Testing Methods

Plant and Equipment

• Welding Machine
• Threading Machine
• Grinding Machine
• Pipe Cutting Machine
• Mechanical Tool Box
• Electrical Tool Box
• Blower
• Megger
• Mechanical Jack
• Compressor
• Welding Goggles and Gloves
• Spirit Level
• Vernier Caliper
• Cable pullers
• Painting Equipment’s
• Lifting Equipment’s
• Drilling Machines
• Hammering Machines
• Hilti Working Tools
• Power Tools
• Laser Alignment Equipment
• Temperature Sensors
• Noise Level Measuring Instruments
• Tachometer
• Volt meter Ammeter
• Jacks and Supports
• Holiday Detector

Pre Fabrication and Installation of Core/Containment Piping

The Core pipes will be blasted, painted as per the technical painting specifications following all the stage inspection process for surface preparation, primer coat DFT and final coat DFT. The details will be recorded (as inspection reports) and submitted for clients review. Details shall be available on site for blasting, painting, containment & cladding of pipe.

The Containment pipes will be Blasted, Painted & cladded with FRP as per  the technical specifications following all the stage inspection process for surface preparation, primer coat DFT, final coat DFT and Holyday testing. The details will be recorded (as inspection reports) and submitted for clients review.

Coating & FRP Cladding on weld joints will be carried out only after successful completion of the pressure test.

The Major quantity of containment pipes (all full lengths) will be cladded with FRP off­ site.

Pipe Fabrication Method on Site

The pipes need to be cut, fabricated and welded for fine adjustment for the length at site based on the actual site layout when we install at site.

This is not recommended to do at the shop due to the fact that if there is any minor change while installing, will require a rework.

Fabrication contractor shall prepare the maximum portion of the job at their workshop (Preparing the pipes for installation) and the remaining part at project site (Sliding the inner pipe to the outer pipes (Short lengths) and making the weld joints) considering the progress at site avoiding any kind of rework.

The end pieces are to be done at site only due to precise length adjustments.

Welder Performance Qualification will be carried out as per approved WPS/PQR and the same will be witnessed by consultant/client.

Each welder will have an identification number for traceability of all welders on the job.

Welding of the pipes will be carried out as per the approved WPS by qualified welder only.

The joint design will be ensured for compliance with WPS checking the edge preparation, root gap, bevel angle, land etc.

The welding consumables will be under the control of QC Engineer.

The electrode selection as per WPS, baking of electrodes wherever required by calibrated baking ovens, portable holding ovens issued for welders on job, calibration of welding machines and electrode baking record will be maintained and ensured by the QC engineer for clients review.

The NDE for the pre-fabricated pipes will be carried out based on the segregation made on piping class and Project Specifications.

The scope for RT (decided based on pressure rating as per project technical specifications) will be identified at site and the same will be ensured for its compliance (as test reports).

Carry out the applicable stage inspections during welding as per the ITP and ensure the presence of all the responsible participating parties during inspection.

The following inspection reports will be maintained and be concurred from main contractor after successful completion of subsequent stages:

• Fit-up and Alignment Inspection Report
• Welding Visual Inspection Report
• RT report

The joint reference will be identified near the weld joint where the details including weld joint number, welder number, line ISO number etc., will be transferred by suitable means (via. permanent paint markers or direct hard punching on surface). Such joint references will be retained till the final pressure test.

Routing of the pipes on steel columns, sleeper bays will be studied by the piping engineer.

All the pre-fabricated pipes will be covered at the ends by suitable means so as to ensure debris free inside surface. Before covering the pipes, ensure the removal of foreign particles.

Pre-fabricated pipes will be coated as per the technical specifications following all the stage inspection process for surface preparation, primer coat DFT and final coat DFT. The details will be recorded (as inspection  reports)  and  submitted  for  clients review.

Coating on weld joints will be carried out only after successful completion of the pressure test.

Before shifting   the  pre-fabricated  pipes    to    site,  it    shall  be  ensured for its completeness in all respects (NDE, paint coating etc.,).

All the pre-fabricated pipes are identified on pipe by putting up a sticker or by punching the details i.e. drawing no., line no., joint no., welder no. etc.

During transit of pre-fabricated pipes to site, proper care (by suitable means like wrapping with plastic cover sheets, using rubber sheets to avoid contact with metal slings while lifting etc.,) will be taken not to damage the coating on pipe surface.

After shifting the pipes to site, the receiving end inspection will be carried out for any transit damages (like coating damage etc.,). Any damage will be tended before proceeding with the erection.

Dimensional check of the pipes will be carried out at site to identify trimming/shortcoming requirements.

Erection of pipes on structures will be carried out in concurrence with the job safety analysis to ensure safe working Tools, tackles and the lifting equipment’s are ensured for its adequacy and suitability for the job requirements. Proper concurrences are met and approved prior to execution.

Risk assessment study will be carried out by the Safety Officer and will be submitted separately to client for review and approval.

All the pipe works will start after the approval of the coordination drawings.

Ensure the availability of necessary scaffolding platforms to enable rigging activities and subsequent joint fit up/welding should be ensured prior to the execution.

Provide the sleeves as per the site requirements.

Prior to joint fit up, the provision of permanent supports will be confirmed with the drawing. Wherever required, temporary supports will be provided to avoid line distortion while welding. Main contractor is responsible for provision of temporary supports. Carry out the welding of field joints as per WPS approval.

The orientation of drains and vents shall follow the universal rule of highest point vents and lower point drains.

Wherever flange connections exists, they will be covered at their faces to avoid damages at transit (especially at gasket seating faces) by suitable means like wooden blinds, plastic caps etc., make sure the use of approved type of gaskets.

The regularization works after the job completion, like removal of fit up cleats, weld spatters (if any), temporary supports etc., will be carried out and ensured.

NDE for field weld joints will be carried out wherever applicable as per project technical specifications. Such stage inspections will be backed by NDE and submitted for client’s review.

All the valves will be connected with the piping with threaded connections.

Piping connection with Tanks will be threaded joints.

Hangers & Supports

Hangers & supports will be provided as per approved drawings & project specifications.

Fabrication and Testing Core Piping System

Core Piping must be fabricated and tested before installing the secondary containment fittings to allow visual and soap testing of core pipes.

Pneumatic Testing

A punch list for jobs to be carried out will be prepared by the QC Engineer and submitted. A walk down inspection of the entire loop will be performed for confirming the drawing requirements.

Before pressure testing the piping must be isolated from the tanks and dispenser units.

For double wall piping systems, the primary product transfer core lines shall be subject to an air test of 1.5 times the working pressure but not less than 350 kpa (50 psi).

The containment Lines shall be subject to an air test.

All joints must be soaped to assist in locating potential leaks.

Pipe cleanliness for inside and outside surface will be carried out. For inside cleaning, card board bursting will be carried out for the entire test loop and cleanliness will be ensured prior starting of Pneumatic testing.

A Pneumatic Testing Pack will be compiled by the QC Engineer which will contain the following:

• Test drawings showing test limits
• Drawings list
• Piping NDE test reports
• Punch list (post/pre)
• Line welding History Sheet (with NDE reports)
• Pressure Test Checklist
• Calibration certificates of pressure gauges used for testing
• Reinstatement check list
• Pneumatic Testing certificate

The test pack will be submitted for client’s review and approval before the starting of Pneumatic Testing.

Fill air step by step through hoses at the lowest points in the loop. After ensuring priming in the loop, start pressurizing to the test pressure (1.5 times the design pressure or as per the project specifications).

Holding time for the test pressure shall be as per ASME B 31.9 / project specifications.

In the case of failure in the test (if any) release the air and conduct repairing and re-testing with the above procedure.

On completion of Pneumatic Testing, release the air gradually, ensuring proper safety precautions. After complete releasing of air, the loop should be air flushed to ensure removal of moisture entrapment.

Reinstate the test loops – Paint coating at weld joints, isolation of pressuring equipment, moisture removal by air flushing etc.

Fuel Oil Piping Fabrication, Erection & Installation Checklist

Check that relevant MIR & Shop drawing are approved

Mark the routing as per approved drawing or as per condition on site

The supplied pipes are free from defects, dent or deformations

The surface of pipes are clean and clear of galvanizing, paint, water, oil or grease

Check the support are properly fixed as per approved drawings & approved material

Check the identification of the services pipes, sleeves, valves and accessories

Check the accessories, valves, flexible connector are properly installed as per approved drawings

Check the schedule of pipes that installed are correct as per approved drawing

Check for weld & check the possible leakage

Check for wrapping on underground pipes (Holiday testing)

Testing Checklist for Fuel Oil Piping

All high points have a tap or vent and that these are all closed

Blank, plug or seal any open ends and use valves to limit the test section of piping to about 30 meters

Remove or blank off any vulnerable inline fittings and components that may be damaged by the test pressure

Ensure that the air compressor used for testing can provide the testing pressure range and it is free from any defects

Ensure that the testing gauge is functioning correctly, has the correct range and is having valid calibration certificate

All flexible connections between the compressed air supply (or pump) are securely fastened at both ends to prevent ‘whipping’ should one end become detached

No work should be carried out on the piping during the testing

All the rooms through which the piping passes are cleared of all personnel

Air testing of the system, for a minimum of 350 Kpa for 2 hours

Testing of coating for underground pipe (Holiday testing)