Maintain the Boiler Pressure Vessel Flashcards
(20 cards)
Any repair work on the pressure vessel must be performed by who
Licensed Boiler Contractor
In a firetube boiler, the tubes are typically welded at which end
Firebox end
On a firetube boiler which end is the end exposed to the hottest combustion gases
Firebox end
How are the tubes connected on the back end of a firetube boiler
The tubes are typically rolled at the “back end” of the boiler
Which end is where the tubes are inserted and secured into the tube sheet, creating a seal through the process of rolling.
Back end
What do you do if you find a rolled tube slightly leaking during a hydro test
You can re roll it but it is possible once the unit is heated back up the tube wont leak due to expansion
One method to check for cracks is using what
a liquid dye penetrant (usually red).
How does a liquid dye penetrant test work
(spray)
The penetrant will bleed through the developer exposing the crack.
If you find Excessive cracking what may need to be done
tube sheet replacement or may result in the condemning of the pressure vessel
Who decides what to do if there is excessive cracking in the sheet
This will be up to the Safety Officer and equipment owner.
Who can weld in the new tubes during a replacement
a licensed boiler contractor employing pressure welders that are certified for the proper weld procedure
What other test can you use to check for cracks (Magnet)
Magnetic Particle Examination
How does a Magnetic Particle Examination work
A small section of the work piece is magnetized and sprayed with a powdered spray containing iron particles and a fluorescein dye.
The magnetic particles will collect along the crack.
What other test can be used to find metal thickness
Ultrasonic Testing
How does Ultrasonic Testing work
Ultrasonic testing provides accurate thickness readings with minimum surface preparation.
Which tests shows detail of welds.
Radiography or X-ray
What must be done while doing a Radiography or X-ray as it is dangerous
install barricades and signage and limit access to only those involved in the testing.
What is often necessary when replacing 1 tube
Removing all the tubes around it
Once the replacement tubes are ready what do you do with the ends
they are expanded into the upper and lower drums, securing them firmly in place.
Additionally, to create a pressure-tight combustion side what must be done
fins must be welded between each tube on the outermost tube wall.
