Pre commissioning
Pre-commissioning activities are defined as those activities,
which are required to be performed after completion/ installation, inspection, hydro testing etc. of an
equipment or system to make it ready for commissioning.
Pre-commissioning activities shall include system checking as per P&IDs/Drawings, site modifications,
internal inspection of equipment/vessels,
flushing/steam blowing,
air blowing of pipelines including gasket blowing, purging of system using inert gas, leak test both for low / high pressure systems, calibration
of instruments,
checking of the electrical equipment for proper earthing, continuity, insulation resistance, conducting operability test on individual equipment/system,
charging of chemicals.
Fabrication and supply of temporary facilities, for example, temporary bypasses, spools, blinds, jumpovers, vents, strainers, screens etc and any left
out important activity
felt necessary for start of commissioning.
A detailed checklist of pre-commissioning and commissioning activities for each equipment, subsystem, system and unit/Plant as a whole is to be made. This checklist to indicate
the checks/test to be carried out on each equipment / system and shall also indicate the sequence and schedule of the activities.
For the purpose of execution of these pre-commissioning activities, the process unit shall be divided into system and sub-systems so that
pre-commissioning activities of
each system/sub-system can be progressively carried out along with the construction activities.
General Procedure for pre commissioning:
Rotation and Alignment
Any rotating machinery e,g pump shaft, agitator shaft of batch reactor, shaft of batch crystallizer etc shall be checked for correct direction of rotation and for freedom of
moving parts before connecting the driver.
Check all lubricants and their appropriate quality, fill etc. before operating the equipment.
Carry out no load run of motors and turbines etc.
Check bearing temperatures, vibration, over speed trips function of different safety device and other relevant tests. Carry out adjustments as and when required.
Make hot alignments and any adjustments required after equipment has been put in operation. (Like thermic fluid hot oil pumps)
Manufacturer representative of major or critical equipment's shall be called during installation and/or pre-commissioning and commissioning for proper start-up of the equipment's.
Packing the Seals
Install mechanical seals, permanent packing and accessories, wherever applicable.
if necessary, adjust and replace mechanical seals, packing, and accessories during pre-commissioning / commissioning period.
System Check / Inspection
Inspect the facilities conform to the approved P&IDs, AFC (Approved for Construction) Drawings, Vendor documents and Job Specifications Approved for Construction,
Flushing and Drying
Flushing schemes for various Systems / Sub-systems / Equipment's should be prepared as per requirement.
Perform flushing using fresh water, blowing air in all above ground and underground pipelines to remove dirt, welding slag, etc.
after hydro testing (along with gasket / sheet blasting).
Steam lines shall be flushed using steam as the flushing medium.
The Systems/ Sub-systems / Equipment's flushed with water shall be followed by blowing with air/nitrogen for the removal of free water. The system required to be kept under
inert pressure as recommended by the licensor/vendor is to be kept under inert pressure.
Instrument piping and tubing shall be flushed.
Dry out all equipment and piping in general by water draining from all low points and blowing air/nitrogen as applicable.
Temporary Spools, Strainers, and Blinds
Provide and install all the strainers properly, whether temporary or permanent.
Clean strainers whenever required during pre-commissioning and commissioning.
Provide, install and remove all blinds from the Systems / Sub-Systems / Equipment required for flushing or operation.
(Install and dismantle temporary pipe spools during pre-commissioning and commissioning).