API RP 573 Inspection of fired boilers and heaters

API RP 573 is a recommended practice developed by the American Petroleum Institute (API) for inspecting fired boilers and heaters. The document provides guidelines for inspecting these types of equipment to ensure their safe and reliable operation.

The scope of API RP 573 includes the inspection of fired boilers and heaters used in the petroleum industry. This includes equipment used for refining, petrochemical production, and other related processes.

The document guides the inspection of various components of fired boilers and heaters, including:

• Furnace and refractory
• Tubes and tube sheets
• Burners and burners management systems
• Fuel piping and fuel trains
• Water level controls and safety devices
• Instrumentation and control systems

API RP 573 also provides recommendations for inspection frequency and methods, as well as criteria for determining the condition of equipment and determining the need for repairs or replacement.

Overall, API RP 573 is to help ensure that fired boilers and heaters are operated safely and reliably, with minimal risk of accidents or failures that could harm personnel or damage equipment and property.

Inspection of the furnace and refractory

The following are some of the checks that can be performed during the inspection of the furnace and refractory of a fired boiler or heater, as outlined in API RP 573:

• Visual inspection: Inspectors can perform a visual inspection of the furnace and refractory to check for any signs of damage or wear, such as cracks, erosion, or corrosion. They can also check for any signs of overheating or hot spots.
• Thickness measurement: Inspectors can measure the thickness of the refractory lining using ultrasonic or other non-destructive testing methods. This can help determine whether the refractory is within acceptable limits or whether it needs to be replaced.
• Refractory density: Inspectors can measure the density of the refractory lining using a density gauge. This can help determine the quality of the refractory and whether it is still in good condition.
• Refractory anchors: Inspectors can check the condition of the refractory anchors, which are used to hold the refractory lining in place. They can ensure that the anchors are secure and not corroded or damaged.
• Burner placement: Inspectors can check the arrangement of the burners in the furnace to ensure that they are correctly aligned and not causing any damage to the refractory lining.
• Flame impingement: Inspectors can check for any signs of flame impingement on the refractory lining, which can cause damage and reduce the life of the lining.

Inspection of tubes and tube sheets

The following are some of the checks that can be performed during the inspection of tubes and tube sheets of a fired boiler or heater, as outlined in API RP 573:

• Visual inspection: Inspectors can perform a visual inspection of the tubes and tube sheets to check for any signs of damage or wear, such as cracks, corrosion, or erosion.
• Thickness measurement: Inspectors can measure the thickness of the tubes and tube sheets using ultrasonic or other non-destructive testing methods. This can help determine whether the tubes and tube sheets are within acceptable limits or need replacement.
• Tube sheet support: Inspectors can check the condition of the tube sheet support and ensure that it provides adequate support to the tubes.
• Tube-to-tube sheet joints: Inspectors can check the condition of the tube-to-tube sheet joints to ensure that they are tight and secure.
• Expansion joints: Inspectors can check the condition of the expansion joints used to allow for thermal expansion and contraction of the tubes.
• Plugging: Inspectors can check for any signs of tube plugging, which can cause reduced heat transfer and the boiler's or heater's efficiency.

Inspection of Burners and burners management systems

The following are some of the checks that can be performed during the inspection of burners and burner management systems of a fired boiler or heater, as outlined in API RP 573:

• Visual inspection: Inspectors can perform a visual inspection of the burners to check for any signs of damage or wear, such as cracks, corrosion, or erosion.
• Flame pattern: Inspectors can observe the flame pattern to ensure it is stable and not impinging on the refractory lining or other equipment.
• Fuel supply: Inspectors can check the system to ensure that it provides the proper fuel to the burners and that the fuel is being correctly atomized.
• Ignition system: Inspectors can check the ignition system to ensure that it works correctly and that the burners are ignited safely and reliably.
• Flame safeguard system: Inspectors can check the flame safeguard system, ensuring that the burners are operating safely and shutting them down in case of a flame failure or other issues.
• Burner management system: Inspectors can check the system to ensure it functions correctly and that all safety interlocks and controls work as intended.

Inspection of fuel piping and fuel trains

The following are some of the checks that can be performed during the inspection of fuel piping and fuel trains of a fired boiler or heater, as outlined in API RP 573:

• Visual inspection: Inspectors can perform a visual inspection of the fuel piping and fuel trains to check for any signs of damage or wear, such as cracks, corrosion, or leaks.
• Pipe support: Inspectors can check the condition of the pipe supports to ensure that they provide adequate support and prevent undue stress on the piping.
• Valves: Inspectors can check the condition of the valves in the fuel piping and fuel trains to ensure that they are functioning correctly and not leaking.
• Filters: Inspectors can check the condition of the filters in the fuel piping and fuel trains to ensure that they are not clogged and allow proper fuel flow.
• Pressure regulators: Inspectors can check the condition of the pressure regulators in the fuel trains to ensure that they are functioning correctly and maintaining the proper fuel pressure.
• Combustion air: Inspectors can check the condition of the combustion air supply system to ensure that it provides the proper air for efficient combustion.

Inspection water level controls and safety devices

The following are some of the checks that can be performed during the inspection of water level controls and safety devices of a fired boiler or heater, as outlined in API RP 573:

• Water level indicators: Inspectors can check the condition of the water level indicators to ensure that they are functioning correctly and provide accurate readings of the water level in the boiler or heater.
• Low water cutoff: Inspectors can check the condition of the low water cutoff device, designed to shut down the burner if the water level drops below a safe level.
• Feedwater control: Inspectors can check the condition of the feedwater control system, which is responsible for maintaining the proper water level in the boiler or heater.
• Pressure relief valves: Inspectors can check the condition of the pressure relief valves, designed to release pressure in the event of an overpressure condition.
• Safety valves: Inspectors can check the condition of the safety valves, which are designed to release pressure in the event of an overpressure condition.
• Flame scanner: Inspectors can check the condition of the flame scanner, which is designed to detect the presence of the burner flame and shut down the burner if the flame is not detected.

Inspection of instrumentation and control systems

The following are some of the checks that can be performed during the inspection of instrumentation and control systems of a fired boiler or heater, as outlined in API RP 573:

• Calibration: Inspectors can check the calibration of the various instruments and sensors in the control system to ensure that they provide accurate measurements.
• Control loops: Inspectors can check the condition of the control loops in the control system to ensure that they are functioning correctly and controlling the various parameters of the boiler or heater as intended.
• Alarm systems: Inspectors can check the condition of the alarm systems in the control system to ensure that they are functioning correctly and provide timely and accurate alarms in the event of a problem.
• Shutdown systems: Inspectors can check the condition of the shutdown systems in the control system to ensure that they are functioning properly and shut down the boiler or heater in the event of a critical problem.
• Human-machine interface: Inspectors can check the condition of the human-machine interface in the control system to ensure that it is functioning properly and provide operators with the necessary information to monitor and control the boiler or heater.
• Data logging: Inspectors can check the condition of the data logging system in the control system to ensure that it records the necessary data for analysis and troubleshooting purposes.