Block 2 - Maintain Boilers & Ancillary Equipment Flashcards
What is the average annual fuel consumption of a boiler compared to its initial cost?
More than four times its initial cost in fuel every year.
What is the primary purpose of a boiler inspection?
To provide assurance of equipment integrity and minimize safety issues.
What is a secondary function of boiler inspections?
Acting as an early warning of potential problems.
What is the minimal inspection frequency for boilers established by law?
It is established by law and the insurance company covering customer liability.
How often should the pressure vessel waterside be inspected after initial operation?
Three months after initial starting and at regular 6-, 9-, or 12-month intervals.
True or False: Steam boilers typically require an internal inspection once every two years.
False. They require an internal inspection once per year, at a minimum.
What can lead to pitting, corrosion, and formation of sludge in hot water systems?
Introduction of raw water make-up or air.
What is the responsibility of the equipment owner and operator regarding boiler maintenance?
They are responsible for performing maintenance on the required schedule.
What must be done to prepare equipment for inspection by a safety officer?
Remove jackets, perform non-destructive tests, open and clean every boiler or pressure vessel.
What is the leading cause of deterioration of pressure vessels?
Improper water treatment.
What should be regularly checked to confirm the success of the boiler water treatment?
Boiler water chemistry.
Fill in the blank: The waterside of the pressure vessel must be kept clean from _______.
grease, sludge, and foreign material.
What should be done if excessive mud or sludge is noticed during the blowdown?
Revise the scheduling or frequency of blowdown.
What should every boiler inspection start with?
A complete visual inspection of the exterior.
What are the safety guidelines when performing a boiler inspection?
Follow safety rules, lock out valves, notify operators, test for oxygen levels, and never inspect alone.
What is the general rule regarding pressure testing against instrumentation?
Never pressure test against instrumentation.
What should be done with the pressure vessel interior after inspection?
Flush out with a high pressure hose.
What can scale formation in firetube boilers lead to?
Overheating of boiler metal, tube failures, and costly repairs.
What is the importance of monitoring combustion analysis in relation to scale formation?
Stack temperatures will be elevated due to reduced heat transfer.
What should be done if deposits are not fully removed by flushing?
Consult with the boiler manufacturer’s authorized representative.
Fill in the blank: An ongoing water treatment program should be set up with a _______.
boiler water treatment specialist.
What is required for internal inspections of vessels?
Confined space entry and isolation requirements.
What tools should be taken during an internal waterside inspection?
Working flashlight, camera, and scraping tool.
True or False: It is acceptable to enter a boiler with a high voltage light.
False. Never enter a boiler with a high voltage light.
What should be done if the internal inspection is made at the request of an authorized inspector?
Ask the inspector to observe conditions prior to cleaning.
What is a sign of leaking tubes in a boiler?
Excessive water on the fireside.
What is the impact of scale formation in boilers?
Scale formation will reduce heat transfer and result in elevated stack temperatures.
This can affect combustion analysis.
What should be done to the pressure vessel interior after an inspection?
Flush out with a high pressure hose.
If deposits remain, consult with the boiler manufacturer’s representative.
When is acid cleaning required for boilers?
In extreme cases when deposits are not removed by flushing.
Professional advice is recommended for acid cleaning.
What can extreme scale build-up in a water tube boiler affect?
It will impede water flow through the heat exchanger.
This is particularly problematic for coil tube designs.
What should be monitored during boiler inspections?
Take pictures and make notes on the current inspection.
Compare observations to previous inspections.
What should be checked at the point of chemical feed?
Ensure good distribution through the boiler before it contacts the blowdown pipe.
What should be inspected in continuous blowdown piping?
Look for corrosion or plugging.
What does a broad band water line indicate?
An unstable water level.
What are signs of oxygen corrosion in boilers?
Well-defined pits or a very pockmarked surface with reddish-brown oxide caps.
Active pits expose black iron oxide or shiny metal when the cap is removed.
What should be checked regarding sludge in boilers?
Excessive sludge deposits could indicate hard water intrusion or insufficient bottom blowdown.
What is the purpose of removing plugs from low water cut-off piping?
To visually inspect the piping and clean or replace as required.
What indicates a need for increased frequency of column blowdowns?
The power engineer must increase frequency if sludge or scale is present.
What should be done to check for burner/combustion issues?
Look for signs like flame impingement and soot deposits.
How can soot be cleaned from firetube boiler tubes?
Using specialty tools that feed a steel fish tape with an attached brush while a vacuum extracts soot.
What maintenance is required for boilers firing digester gas?
Wash off the white coating on the fireside of the tubes periodically to maintain heat transfer.
What should be checked regarding baffles and shelves?
Inspect welds for cracks caused by vibration.
What should be done after cleaning the waterside of a boiler?
Replace all waterside handhole and manhole gaskets.
What should not be applied to handhole or manhole gasket surfaces?
Any sealant like silicone.
What is the time-sensitive aspect of safety valves?
The valve serviced date must be monitored to avoid storing serviced valves too long.
What should be done when performing a pop test on safety valves?
Raise the operating pressure to the set pressure to allow it to open and reseat.
What can frequent use of safety valves cause?
Leakage due to wear on the seat and disc.
What must be done for safety valve repairs?
Only the manufacturer or authorized representative should perform repairs.
What should be monitored on feed pumps and blowers?
Check the amp draw for signs of bearing deterioration.
What are the two methods of boiler storage?
Wet layup and dry layup.
What is required for wet layup of a boiler?
The boiler must be flooded with chemically treated water to prevent air separation.
What is the purpose of dry layup?
To allow complete drying of the boiler by draining and promoting air circulation.
What is wet layup in boiler maintenance?
The boiler must be flooded so there is no water/air separation line in the vessel. The water is chemically treated with corrosion inhibitors.
Wet layup helps prevent corrosion during short-term storage.
What is dry layup in boiler maintenance?
The boiler is completely drained with all hand hole and man hole covers removed. Air circulation is promoted in the waterside to completely dry out. This is best for long-term storage.
Dry layup minimizes the risk of corrosion over extended periods.
True or False: In wet layup, the boiler must be completely drained.
False
In wet layup, the boiler must be flooded with treated water.
Fill in the blank: In dry layup, the boiler is completely _______.
drained
This process removes all water to prevent corrosion.
What chemical treatment is used in wet layup?
Corrosion inhibitors
These inhibitors are essential to protect the boiler from corrosion while in storage.
What is promoted in the waterside during dry layup?
Air circulation
Air circulation helps ensure that the boiler completely dries out.
