A Brief Concepts  to Commissioning 

Commissioning is the phase in a project when design process fluids are introduced to the process. 

Note that for hydrocarbon systems the commissioning activities commence with inerting operations. Commissioning activities normally consist of activities associated with running or operating the plant and include operating adjustments necessary for satisfactory operation of the plant or part there of. Also included are “Functional checks” which are methods used to prove that an item of mechanical equipment or control system functions correctly.

Before completion of Pre-commissioning activities  we can not move to commissioning phase .

Pre-Commissioning activities start when the plant, or system, achieves Mechanical Completion. Frequently,however, Pre-Commissioning activities overlap Mechanical Completion activities.

Pre-Commissioning activities include: checking for design conformity, checking the status of electrical, mechanical and instrument installations, running-in of equipment, flushing and cleaning activities, drying, etc.

Pre-Commissioning Period:

The site phase of the project will commence at approximately 60% construction completion and activities will be mainly centred on: Progression of all of the procedures developed during the Home office phase of the project Co-ordinating system turnover and completion Monitoring and reporting progress Co-ordinating resources, including sub-contract and vendor support Liaising with licensors.

Main activity developed during Pre-Commissioning phase are:

Punch-Listing:

              Punch-Listing will be undertaken on a systems basis. An integrated team will be formed to participate in Punch Listing. An initial Punch-List will be undertaken immediately prior to system handover for Pre-Commissioning purpose. This will probably occur at around the hydrotest time. Punch-List items generated at this stage will be incorporated into the Project master Punch-List system. A final Punch-List will be undertaken by system immediately prior to the commencement of commissioning activities. This will be a less stringent Punch-List and aimed at checking the system over before introducing hydrocarbons. Utilisation of the Pre-Commissioning check sheets will assist in completing a full range of required checks. Punch-Listing progress will be recorded on an A3 set of P&IDs.

System Cleaning :

              This would include directing the cleaning of systems either by flushing, blowing or chemical cleaning by issuing directives for the necessary temporary connections, utilities and proper line up of the system to be cleaned. When the services of a chemical cleaning subcontractor are required, the Commissioning Team will monitor his performance to ensure a satisfactory cleaning job. Before each system is closed for operating, the lines and equipment would be inspected for cleanliness. Cleaning progress will be recorded on an A3 set of P&IDs. 

Equipment Run-In:

             This would include planning and co-ordinating Vendor representatives for the running in of the equipment and obtaining the necessary utilities to accomplish the runin for equipment such as blowers, pumps, compressor, motors, turbines, and other machinery or mechanical equipment without process fluids before start-up.

 Vessel Loading:

            This phase would ensure that all catalysts, packing, resins and desiccant loading is performed in a proper manner and accurate records and samples of each material loaded are retained. 

               " When all the activities foreseen in the Pre-Commissioning phase (the Process Units will be ready to receive hydrocarbons, most of the utility systems will be live to the respective units and all of the hydrocarbon lines will be positively isolated at the unit battery limits) have been performed successfully a Ready for Commissioning Certificate will be issued and so Commissioning activities can start."

Commissioning & Start-Up Period:

        

    Once the unit is precommissioned, the Commissioning Team will conduct the following main activities: 

•      Purging
•      Leak Test / Tightness Test
•      Function Test

         The Commissioning Subcontractor Team would take care in troubleshooting any operating or process problems, should they arise, and would investigate any operating deviations as they occur.

Team will:

 a.) Develop and Review Specific Operating Instruction

 b.) Conduct and supervise all activities during the Introduction of Feedstock to the Units

 c.) Stabilize the Unit

Commissioning Complete :

When all commissioning for a process unit is completed the unit is declared “Ready to Start-up”. At this point normal conditions are established to produce the designed products.

                                                                      (fig.1)

                                                                (fig.2)

   Above figures show the flowchart of pre-commissioning , commissioning  activities  which are to executed step by step for uninterupted  performance guuarantee run test (PGTR) which is final phase/ step of commissioning of project.