Commissioning is an extremely important and necessary part of any plant installation process to ensure it has been correctly installed to industry standards. Leading burner manufacturer and distributor, EOGB Energy Products Ltd, offers 10 top tips for engineers in charge of commissioning commercial and industrial heating installations:
- Arrange an initial meeting
Firstly, it’s important to have a meeting with the person who will be in charge of the plants’ operation to be informed of:
- What process the plant is being used for
- What is expected from the operation
- How the plant is controlled
- If the temperature is critical and, if so, to what point
- Collect all the correct documentation
The following documentation should always be made available:
- Drawings of the plant layout, including flue and ventilation design
- All manufacturer’s instructions
- Gas supply testing and purging certificates as per IGE-UP-1 or 1A Edition 2
- Electrical schematic drawings
- Undertake a visual inspection
Before any commissioning can commence it is vital that the plant is visually inspected. The following questions should be addressed:
- Are boilers or plant machinery and/or equipment installed correctly, safely and to manufacturer’s instructions?
- Is the area safe to have this installation installed?
- Is the gas supply correct?
- Is the flue correctly designed and installed?
- Are the necessary electrical supplies correct?
- Is the equipment installed suitable for the application intended?
- Check the boiler against the manufacturer’s instructions
This must be done to ensure that:
- The electrical connections to the boiler are correctly fitted and that the boiler can be electrically isolated
- The burner is correctly installed (particular attention should be paid to the burners insertion depth into the boiler – if in doubt the boiler and burner manufacturers should be consulted)
- Inspect the gas supply
The gas supply to the plant should be designed and installed to IGEM/UP/2 Edition 2 and should be inspected to ensure that:
- Testing and purging has been carried out and documented
- The correct materials have been used
- The pipework is correctly sized
- The correct methods of jointing have been used (e.g all joints must be welded over 50mm)
- Emergency control valves have been fitted and are usable and the control levers fall to the ‘off’ position
- There is an emergency control valve fitted at point of entry into the plant room
- Any regulators required are fitted in the correct location
- Purge points have been suitably capped
- Review the flue design and installation
The flue design and installation should be reviewed and guidance sought from IGEM/UP/10, BS6644:2011 and BS5854. The commissioning engineer is required to visually check that:
- The flue is jointed securely and suitably secure
- The flue material is suitable
- Any flue draught stabilisers have balance weights fitted or present for commissioning
- Any condensate drains fitted are terminated correctly
- Flue bends and horizontal runs have been kept to a minimum
- The flue terminates correctly
- A flue flow test has been performed and observed along the whole flue length
- Think about ventilation requirements
Natural draught or mechanical ventilation provisions need to ensure the following:
- They are suitably sized for the max KW heat input of the plant
- They have suitably designed vents to ensure unrestricted air flow
- If mechanical and flue extract fans are used, care must be taken when measuring air flow that the plant room is not being put into a negative state
- Always conduct pre-commissioning electrical tests
The following electrical tests are required:
- Earth Continuity Check
- Polarity Check
- Resistance to Earth Check
- Three Phase Motor checked for voltage and correct rotation.
- Perform dry and live run procedures
In order to check the safe operation of the installation, a dry run procedure must be performed. This ensures that the burners start up and lockout sequences are operating correctly before introducing gas.
Once the preliminary safety checks have been completed, the live run procedure can be carried out. After a successful ignition, the controls can be checked for successful shutdown when enable is removed.
It’s extremely important to monitor O2, CO2, CO and flue gas temperature carefully with a calibrated combustion analyser to achieve good combustion. The low fire flue gas temperatures also need to be observed and the flue gases and a true gas rate of each appliance checked accordingly.
- Pay attention to combustion calculations
Stoichiometric calculations are often discussed but realistically cannot be achieved in practice as a reasonable percentage of excess air is required to maintain complete combustion.
Both too little and too much excess air can encourage carbon monoxide to be produced. High excess air content can also encourage higher heat losses out of the flue, so it’s important to be aware of excess air levels during boiler commissioning.
Once the plant has been thoroughly checked and all safety interlocks proved, it can then be handed over to the site and all necessary operative training provided, including advice on maintenance schedules discussed.