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Safe Pre-commissioning commissioning of ammonia urea fertiliser plant

Ammonia – Urea fertiliser plant possess high hazards due to handling and processing hazardous chemicals including Natural gas, ammonia, hydrogen, carbon monoxide, chlorine, etc and critical process parameters such as high pressure and temperature.

Safety of peoples, machines and environment are the key factors for successful plant commissioning. No commissioning can be considered a success if not done safely.

Safe Pre-commissioning commissioning of ammonia urea fertiliser plant
Commissioning of ammonia urea fertiliser plant

Safe Pre-commissioning commissioning of ammonia urea fertiliser plant

First element of pre-commissioning and commissioning is planning to commission of any facility safely and in time. In this stage, organizational chart with roles and responsibilities of all members of commissioning team are framed out. Decide all different types of checklists i.e. structure, piping, mechanical, electrical, instrumentation, etc and develop operating manual.

Planning must be done along with licensors, critical vendors and client so that their team should join the commissioning activities on site.

Ensure advance planning of material requirement. Material like blinds, split pieces, hoses, steam blowing equipment, toolbox/ kit, etc my requires during pre-commissioning and commissioning activities.


Scope of pre-commissioning and commissioning - Ammonia Urea fertiliser plant

Detail scope of pre-commissioning and commissioning of Ammonia Urea fertiliser plant may include main production plants such as ammonia plant, ammonia storage, Urea plant and Urea product handling. Utilities includes raw water facility, water treatment plant, cross country pipeline, Fire water facility, power plant, heat recovery system, nitrogen plant, cooling towers, Effluent treatment plant and rail wagon facility, etc.


Sequence of pre-commissioning and commissioning activities - ammonia urea plant

Below sequence is recommended for ammonia urea plant pre-commissioning and commissioning activities based on its priorities.

  1. Power and control system i.e. electrical substations, central control center, building power, etc.
  2. DCS and PLC systems and instrumentation
  3. Row water and firefighting systems
  4. Effluent treatment systems
  5. Chemical sewer systems and neutralization pits
  6. Service water, potable water and cooling water systems
  7. Instrument air, plant air and air regeneration systems
  8. Water treatment systems.
  9. DM plant
  10. Boiler water system
  11. The nitrogen system
  12. Flare system
  13. Plant safety equipment and fire and gas detection
  14. Fuel gas system
  15. Flushing oil system
  16. Boiler systems with steam and condensate networks
  17. Feed, ammonia storage and product handling systems
  18. All the process units and systems, etc.


Planning for Pre - commissioning activities – Ammonia Urea plant


Formation of Work Packages

The entire facility should be subdivided into the work packages to determine the detail activities, skill and expertise requirement, estimate for effort and duration for particular activity, its scheduling, budget involved, and risk involved well in advance before starting commissioning of plant.  This will help to determine the interlinking of operating systems, status of operating systems completion, formation of loops which can be easily controlled and monitored, etc.

Work packages can be form by constituting the team of experts from each functional area with a process leader. Roles and responsibilities of each members must be identified and well communicated. Leader must ensure the resources and close monitoring.

Identify the different loops and check for an individual loop with respect to P&ID. Checking may include the piping, valves and other instrument items, the support system, the tightness for nuts and bolts, the gaskets, the blinds and temporary blind removal along with blind register, the hydro/pneumatic test reports, flushing and cleaning reports, insulation and painting reports.

Whatever the shortcomings or pending point observations should be incorporated in “punch list” for rectification. Punch list must be signed off and submit the status of completion before handing over for commissioning.

Always maintain vendor instruction file to document information or instructions received from licensor/ vendors/ manufactures which may be readily retrieved by plant commissioning team.



Health Safety and Environment.

All personnel must be trained to operate facility safely in accordance with the safety standards and procedures.

The prime consideration in plant operation and maintenance is assumed to be safety of personnel.

Detailed safety instruction including Dos and Don’ts and procedures must be prepared, approved and communicated to concerns.

Hazards should be identified, and necessary risk mitigation measures should be provided.

Safety procedures should be developed taking into account of rules and regulations.

Detailed fire precautions and first aid procedures should be developed

  1. Work permit – to control critical work, maintenance, repair other work of a hazardous or potentially hazardous nature.
  2. Personnel protection equipment.
  3. Training of all working personals.
  4. Plant maintenance
  5. Safety equipment

MSDS must be made available for all hazardous chemicals.



Sometime hot commissioning and initial start-up are planned at once, in such case, before the commissioning of plant and initial start-up

  • Analytical laboratory should be ready with chemicals and instrument.
  • All equipment, chemicals and analytical manual are available.
  • Laboratory is sufficiently staffed with experienced workers.


Sometime hot commissioning and initial start-up are planned at once, in such case, before the commissioning of plant and initial start-up

  • Mechanical/Electrical/Instrumentation workshop should be ready.
  • All equipment, tools & tackles should be available.
  • Workshop is sufficiently staffed with experienced workers.


Communication and Public Address System

Check for completeness of Public address system in all respect.


Recommended Task for pre-commissioning of fertiliser plant

Here are the recommended tasks should be performed during the pre-commissioning and commissioning of ammonia Urea plant.

Punch point Inspections and record

Commissioning team must inspect the systems and subsystems to verify whether the specified materials/ items have been installed in the facility according to drawings, specifications and project intend. Verify the documents and maintain the record of verification.

The facility inspection can be performed by using standard checklist as approved by commissioning team leader. Note down any exceptions on a separate work order list or punch list with roles, responsibility and target date for correction.

There may be need of special inspections, such as those required by the insurance or governmental agencies (Statutory Requirements), it must be coordinated by experts.


Lubricants Management

Prepare a list of lubricants used for different machines recommended by manufacture and get it approved by in-charge.

Ensure the availability of desired lubricants.

Check for heating/cooling and online clarification of lubricants.

Flush the system and initial charge the lubricants.

All flushing oil should be disposed out as per procedure.

Maintain lubrication after initial charge.


Removal of rust preventives substances

Most of the rust preventives and oil used to protect the equipment from rust during the construction period may harmful to process operation. These oil / rust preventives must be removed completely before equipment take into operation. Record should be maintained.


Packing and seals Management

Ensure the correct installation of mechanical seals and accessories, as required.

Permanent packing and accessories may be requiring at certain equipment.

Adjust and if requires, replace mechanical seals, packing, accessories and other required items during commissioning period.


Remove temporary bracing/ supports

Remove all temporary supports, bracing or other foreign objects that were used for packing or to prevent damages during shipping, storage and erection of vessels, ducts, piping, transformer, machinery or other equipment.

Inspect the equipment and installation thoroughly and repair any damage.


Check rotation and alignment of rotary equipment

Before connecting to the driver, all rotary equipment/ machinery must be checked for correct direction of rotation and for freedom of moving parts.

According to the manufacturer’s tolerances data, perform cold alignment and maintain record.

Ensure hot alignment as applicable according to manufacture guideline.

If need any doweling, perform it according to equipment data sheet and manufacturer guideline.

OEM representative must be involved to witness installation and pre-commissioning of critical and large equipment/ machines.


Tie-ins at unit limits

Inspect the installation as per P&ID and prepare all the system and subsystem for safe tie-ins.

According to specification, arrange for obtaining approval and making the necessary tie-ins at the unit limits/ battery limit.

Maintain blind register and use P&ID for marking the blinding/ deblending requirement. Remove blinds, seals, and so forth as required.


Leak and pressure testing

Prepare detail schedule of non-operating field leak/ pressure test for piping and field fabricated equipment.

Decide the requirement of cold or hot commissioning.

Decide whether any special media required for test purposes.

Conduct all tests in accordance with all applicable codes, specifications, regulations and the OEM instructions.

Pre-commissioning team must witness the tests and maintain the records.

All test media used for leak/ pressure tests must be disposed out in accordance with the owner’s instructions.

Ensure the operational tightness tests is carried out for all identified system and subsystem with equipment and fittings.


Use of temporary screens, strainers, and blinds

For successful flushing activity, identify the needs for temporary screens, strainers and blinds.

Install all required temporary strainers/screens/blinds and ensure cleaning of strainers during circulation.

Remove the temporary strainers when system is adequately cleaned.

There may require providing some blinds or to remove all blinds for flushing.

Maintain the blind register to record the data for providing, installing and removing all blinds required for isolation.


Flushing and chemical / mechanical cleaning

Identify the system and subsystem for flushing or cleaning by chemical or mechanical means.

Identify the system or subsystem for flushing/ cleaning by using permanently installed equipment or by portable equipment.

Decide the acceptable flushing media for particular system/ subsystem.

Conduct all flushing, blowing, and chemical/mechanical cleaning operations with due care and maintaining the safety system where such operation can be accomplished without using permanently installed equipment.

To obtain proper line velocities, flushing and blowing operations can be performed by using permanently installed equipment.

Follow client’s guidelines/ operating procedures for safe disposal of all the cleaning/ flushing media used.

Check system for free of trash and construction debris and maintain records.


Pressure / vacuum safety relief devices

All safety relief devices are critical items and must be inspected, tested and installed properly as per specification.

List out all the safety relief devices with record such as pressure settings data, type of SRV, material of construction, testing date and due date, etc.

Test and adjust all safety relief devices and seals wherever necessary or desirable.

Install all devices safely after testing, adjusting, and tightening and maintain record.


Purging operation by inert media

Ensure the safe and secured connections for purging operation.

Decide the suitable purge material and conduct necessary purge operation safely with permit to work.

Perform the work according to manufacture guideline and follow standard operating procedures with caution boards.


Dry out the facility

To prevent contamination of catalyst, operating fluid or materials, ensure proper ‘dry out’ operation of system, subsystem and equipment.

Identify the needs of portable or fixed equipment for Dry out process.

All equipment must be inspected, tested and certified for dry out systems for refractories, and linings when drying operation is to be accomplished with temporary facilities.

Ensure safety and follow standard operating procedures for drying operation accomplished by means of permanently installed equipment.



After mechanical completion of construction work, maintain adequate housekeeping practices for safe pre-commissioning or commissioning operation.

Remove excess material, temporary facilities, scaffolding, etc and perform rough sweep or rake the area. Pick up the trash and dispose it safely.

Perform washing or further clean-up if required.


Commissioning activities – Ammonia Urea plant

After completion of inspection, testing, alignment, flushing, purging, drying, closure of punch points, etc. proceed for commissioning activities.

Once finished the pre-commissioning activities, protect equipment from normal weather conditions, corrosion, or damage. Ensure the availability of all-important spares and be prepared for other emergency maintenance/ repair job predicted during commissioning activities.


Maintenance tools and spares

Once pre-commissioning is completed, review the list of maintenance spare parts specially gaskets, valves, etc as recommended by the manufacturers for commissioning activities.

Ensure the availability of special tools such as non-sparking tools to attend the leakages of flammable gases.

Maintain adequate spare parts and supplies.

Ensure the availability of trained and qualified technicians to perform the emergency repair or maintenance job.

Ensure availability of special PPEs including chemical suits, respirators, electric arc / flash resistance suit, etc.


Work Environment Survey

Conduct individual equipment noise surveys, as required by the occupational safety and health administration or the client specification.

Conduct survey for illumination level.

Maintain record.


Commissioning activities/ process – Ammonia Urea Plant

Some time pre-commissioning and commissioning activities can be performed simultaneously. After ensuring the closeup of punch points, commissioning activities can be start in presence of critical vendors, licensors and client.


Commissioning of Electrical Systems

Ensure proper earthing system and witness tests.

Perform insulation tests on all wiring except lighting wiring using a Mega ohm meter.

Insulation tests on motor and transformer windings should be done from phase to phase and phase to ground.

Perform grounding system tests to determine the continuity of connections and the value of resistance to ground.

Arrange to get local electrical inspector’s approval according to local or national laws.

Perform breakdown tests on oil samples from oil insulated transformers larger than 100KV.

Perform trials and adjustments on all switchgear, motor control equipment, and generators.

Test and set switchgear and circuit breaker relays for proper coordination.

Energize all substations with approval of the client after completion of all tests and ensuring the availability of firefighting systems/ fire extinguishers.

Check for phase sequence, polarity, and motor rotations.

Check installation of emergency power and lighting systems, including light intensity

Follow standard checklist, SOPs and maintain a record of job completion.


Commissioning of Instrumentation Systems

Check for loop and logic test according to cause and effect diagram.

Conduct non-operating checks to ensure instrument operability. This must be done by removing all shipping stops, check pointer travels and verifying the instrument capability to measure, operate, and stroke in the direction and manner required by the process application.

Instruments must be bench or field calibrated with standard test equipment/ media according to clients or manufacturer instructions. Ensure all required adjustments and control point settings is done and recorded.

Ensure that the SS piping/ tubing from instruments to process piping is properly tightened.

Clean all transmission and control tubing by blowing with cooled and filtered clean air before connecting to instrument components.

Clean all air-supply headers by blowing with clean air and check them for tightness.

Perform leak test of pneumatic control circuits in accordance with the applicable standards.

Ensure proper installation and connections of all system components by verifying their conformance with data sheets, drawings and specifications. Function test should be checked by using dummy transmission signals or by shorting the terminals to verify the design intend/ criteria.

Check all electrical signals and alarm wiring for continuity, correct source of power, and polarity.

Check thermocouples for proper joining of wires, position of elements in thermowells, proper polarity, and continuity of receiving instruments.

Ensure correct tagging is available on each instrument and connections. Tagging must be ensured on orifice plates for ease of identification.

Orifice plate must be installed after completion of flushing operations only. Check and record the bores of orifice plates.  

Isolate or remove, if necessary, inline components such as control valves, positive displacement meters, and turbine meters for pressure testing. Reinstall these items after testing the system with the components removed or isolated.

Isolate or remove components for flushing operations and reinstall them on the completion.

Install any sealing fluids, as required.

Fully pressurize and energize the transmitting and control signal systems(s) by opening process connections at primary sensors and final regulators and by making control mode settings for automatic operation of equipment as the process unit is charged and bought on stream.

Make a schedule of recording of required parameter.


Commissioning of DCS/ESD/PLC/MMS System

Check the proper installation of DCS/ESD/PLC Panels and inside components as per drawing and data sheets.

Check and connect the panel and instrument earthlings at proper places.

Check the IR values for individual cores of power and instrument cables.

Loop checking for all the instrument and power connections.

Connect all the cable to proper terminal blocks inside system panels.

Check and connect the network cables from system to corresponding consoles.

Power up and install the HMI.

Power up the cabinets and ensure the reading of all input signals to DCS/ESD/PLC.

Check output signal from the system.

Check the interface.

Proceed for final loop checking and calibrations as per site acceptance test procedure.


Commissioning activities for vessels

Inspect the vessel internally before and after installation as per defined scope.

Check all instrumentation including PT, FT, LT, SRV, BV, etc.

Flush/ Dry out and install material that are desired.

Ensure the compliances of all statutory requirement.

Review the blind register and boxup after proper execution of work permits.

Ensure tagging and marking of vessel with all fittings.

Ensure the plugging or blinding of open drain points.


Commissioning activities for fired heaters

Perform all non-operating pre firing checks in accordance with the manufacturer’s instructions and checklist.

Perform the pressure test in accordance with the applicable codes, specifications and the client’s instructions.

Check operation of dampers and verify position of indicators.

Check operation of air preheaters, blowers.

Ensure the cleanliness of fuel lines by performing blowing operation and then connect burner pipes.

Dry refractories during initial firing by following the manufacture’s temperature cycles.

Conduct boil out, chemical cleaning, and flushing operations as desired. Ensure safe disposal of wastes and cleaning media in accordance with the established procedure.

Conduct light off, drying, and purging operations.

Get the assistance of OEM or Licensor’s for technical advice during installation, commissioning or start-up,  if desired


Commissioning activities for pumps, compressors and drivers

Ensure that level base plate, sole plates and grout all bearing surfaces are acceptable .

Lighten any excess piping stresses that may be imposed on pumps, compressors, and drivers.

Clean complete lube oil system.

Charge the lube oil, seal oil, and oil cooling system with flushing oil system and circulate for cleaning purposes.

Charge the lube oil, seal oil and oil cooling system with the operating oil recommended by the manufacturer.

Cold testing of overload protection and trip logic actuation/delay timer etc.

Operate equipment and monitor for checking vibration, temperature, trip, governor functioning and other safety device.

Checks for any operating tests and adjustments, as required.

Get assistance of OEM’s service engineer for technical advice during installation or commissioning, if required.

Maintain records


Commissioning of Urea conveyer system

Check for proper alignment between motor and drive pulley.

Check for functioning of pull chord.

Check for operation conveyor belt limit switch for its sideways movement.

Check for proper tensioning in conveyor belt.

Check for conveyor belt joint.

Check the availability of machine guards.

Check the obstacle free platform around the conveyor belt.

Check the function of start-up hooter.

Fill the checklist and OEM instructions.


Commissioning of Storage tanks

Perform leak test/ hydro test according to standard specification.

Disposal of test water must be done in accordance with client guideline.

Conduct chemical cleaning and flushing operations, as required. Dispose out wastes and cleaning media in accordance with established procedure.

Perform dry out activity as required.

Witness test and inspections to extent desired.

Ensure standard tagging of tanks.

Follow permit to work for safe execution of the job.


Commissioning of piping system

All piping must be hydrostatically or pneumatically tested according to specifications and types of services.

Commissioning team must witness field pressure test.

Flush and drain the system properly and install the orifice plate. (Orifice plate should not be installed before hydrostatic testing)

The system should be drained properly, remove blinds, and perform tightness test.

After completion of test, piping and fittings can be insulate or painted. Ensure proper painting of welded joints as per standards.

All welded joints such as longitudinal, girth, and nozzle of underground piping that have not been shop tested shall be left exposed (free from paint, drop, and wrap) until the specified testing has been completed and accepted by client. Piping can be covered or backfilled after final testing of the joints.

Check pipe-hangers, support, guide, expansion joints, and other pipe specialities for the removal of all shipping and erection temporary items.

Identify the requirement for cold and hot tightening of bolts for the designed services. There should be clear instructions for hot setting expansion joints.

Check for pipe-hangers support, guides, and pipe specification for hot settings. If requires, make minor adjustment for system safety.

As specified in data sheet and system specifications, install permanent filter elements.

During commissioning stage, identify and record the support vibration and thermal expansion problem and rectify it immediately.

Ensure proper torque of bolts for both cold and hot services. Re-torque all hot and cold service bolting during commissioning and start-up, if demand.


Commissioning activities - Water Treatment Plants

Follow the commissioning checklist for readiness of system

Ensure completeness and correctness of installations as per drawing and make any non-operating checks that may be required.

Provide and install the initial charge of ion-exchange resins and inert bed material.

Arrange all water treatment chemicals except the initial charge resins.

Make the necessary operating tests and adjustments to water treatment systems.

Obtain the services of a water consultant to advise and monitor the water treatment operation, as required by the Owner.

Ensure readiness of potable water, service water, drinking water systems.


Commissioning activities for Cooling Towers and Fire Water Systems

Inspect for completeness and correctness of installations and make any non-operation checks that may be required.

 Clean the cooling tower basin and install screens in the suction pit before water circulation.

Flush, drain, and clean the cooling tower basins.

 Clean intake screens.

Adjust cooling tower fans to obtain specified tip clearance and test.

 Operate fire pumps to check performance of systems.

Vessels, tanks and other water system equipment as required, fill with water, check for leaks and flush to clean.

Arrange for insurance company inspection of the fire system as required.

Obtain and install all required fire- fighting chemicals and portable equipment such as hoses, fire extinguishers and related equipment.

Establish the water treatment program.

Obtain the services of a water consultant to advise and monitor the water treatment as required.


Commissioning activities for Boilers

Inform IBR inspector in advance

Make a non-operating boiler pressure test in accordance with applicable codes, specifications.

Inspect the boiler for completeness and correctness of installation and make other non-operating pre-firing checks.

Check operation of FD fan, scanner fan, and other equipment for proper operations.

Dry refractories during initial firing by following the manufacturer’s temperature cycles.

Purge, flush, and drain steam mains, as necessary.

Obtain and charge treated water for bailout and initial operation, as required.

Commission auxiliaries as detailed elsewhere under the appropriate equipment type.

Conduct boil out, chemical cleaning, and flushing operation, as required. Dispose of wastes and cleaning media in accordance with the established procedure.

 Obtain the assistance of OEM’s service engineer for technical advice during installation or start-up, if desired.

Conduct all operating tests and obtain the required certification.

Recheck and set pressure-relief valves.

Maintain relevant records for future use.


Commissioning activities – Catalyst and chemical Loading

Inspect the vessel internally for cleanliness, completeness, and proper installation of internal fittings.

Check location and length of instruments.

Check location and fabrication details of distributor piping and internal trays.

Check range of level instrument floats or outside floats cage connection.


Commissioning activities for Waste Disposal system

Inspect facilities for its completeness and correctness of installation and make any non-operating checks to ensure their conformance to specifications.

Operate all equipment and arrange all chemicals and agents related to waste treatment.

Obtain the services of a waste treatment consultant to advise and monitor the system operation as required.


Commissioning activities for Building and Accessories

Check installation including HVAC equipment to ensure their completeness and conformance to specifications

As required, obtain certification that all plumbing, electrical, fire protection, elevator and special materials handling installations canopy with government regulations.

Operate HVAC unit and make all performance tests.



Pre-commissioning and commissioning activities should be prepared after detail discussion and brain storming with highly experience team members who have served in major fertilizer companies. Various codes, published articles and case studies should be referred finalizing commissioning activities and preparing commissioning checklists

Safety should be a high priority when performing any activity related to the commissioning of the ammonia urea plant.

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