Equipment-Boiler Flashcards
Who should operate a high pressure, steam boiler?
- A stationary engineer. In Illinois a stationary engineer is not required.
- Maintenance partner/ trained plant personal
- Our boiler is larger than most and runs about 100 # of pressure
At how many pounds of steam pressure does a Cintas laundry generally operate a high pressure, steam boiler?
• Our boiler operates at 100 psi.
What pieces of equipment in a typical Cintas laundry require steam?
• Steam heater, washers, tunnel finisher, shirt press
When a high pressure steam boiler is being started from cold, should the boiler be brought up to operating pressure quickly or slowly? Why?
- A boiler should be brought up to pressure slowly to minimize the stresses on the boiler.
- Doing so will reduce the expansion and contraction of the boiler and avoid hammering
Should the main steam valve be opened or closed when shutting down a boiler?
• Closed- to maintain pressure in the boiler and minimize the expansion and contraction of the boiler
How should the steam lines be energized and why?
• Slowly, to avoid hammering. At 30psi slightly open the main steam isolation valves to allow pressure to build up slowly. Repeat till valve is completely open.
You open the main steam valve and all the steam lines are popping and shaking. What is happening and what would you do to prevent this from happening in the future?
• To much pressure in the lines, steam is condensing in the lines causing hammering. To prevent in the future, you would want to open the steam valve slowly.
How often is a high pressure steam boiler inspected and why?
- Yearly. To insure the boiler is working properly and verify our chemistry is working. A full shut down & depressurize of boiler. They will open the front swing door and look at the tubes to check for cracks or sagging.
- Our yearly is in January
At what frequency should the controls and safety devices be inspected and tested?
- Require daily validation of the safety devices on the boiler. Plants are required to document this on the FM global red tag document
- Every 6 months by an outside contractor
What is the purpose of a steam trap?
• It is located in the return line after each piece of steam operated equipment to allow condensation to be returned to the boiler feedwater tank.
What is a check valve?
• A check valve allows steam, water, air to move in only one direction to prevent backflow.
Why is chemical treatment important for a boiler?
• To insure appropriate operation of the boiler. Chemical treatment binds up impurities in the water to prevent scaling of the boiler tubes which can cause corrosion and pitting of the tubes and ultimately lead to boiler failure.
What purpose does a water softener provide for a boiler system?
- Removes impurities that cause scaling.
* Using a water softener also reduces the amount of chemicals needed to bind up impurities.
What purpose does a boiler feedwater system provide?
• Provides makeup water to the boiler. Water must be maintained at 175-200 degrees before it can be sent to the boiler.
If your boiler is scaling, what does this mean?
- Have hard water
- Impurities are building in the water side of the boiler. Scaling acts as an insulator and prevents heat from being transferred to the water side of the boiler.
Why should boilers be blown down, and at what areas should blowdown occur?
• Done to remove the sediment that builds in the boiler
• Bottom blowdowns are done daily to prevent scale and sludge buildup.
• Surface blowdowns are done as needed to regulate boiler conductivity. These are done automatically by the system.
Once per 8 hour shift
How often should a bottom blown down occur?
• Once per 8-hour shift. More often if water quality is not good
What does night firing a boiler mean, and why would you do it?
• It means to low fire at 5-10 psi. You would do this to prevent having to change temperatures drastically, save energy, extend the life of the boiler, reduces time it takes to start up.
You walk into your boiler room and you notice a water level within the boiler is lower than the gauge. Therefore, the level is unknown. What do you do?
- Shut the boiler and the boiler feed water pumps off immediately.
- Do not attempt to restart until boiler can be verified safe
You walk into your boiler room and it is operating at only 50 psi. What pieces of equipment, if any, would not function at this pressure?
- The temperature would not be hot enough for the steam tunnel to properly finish product.
- Washers and presses would run but steps would take longer to complete
- Not efficient to run this way.
If the situation in the previous question were to occur, then how would you try to continue to operate, or would you shut down?
• I would move partners around, we would still be able to run the sorts, bulk, mat areas.
What pressure devices are present on a high pressure, steam boiler?
- An operator controller to turn off the boiler when the upper limit is reached.
- 2 safety pop off vales- vented to the outside.
- High limit switch- Sounds alarm
What water level safety devices are present on a high pressure, steam boiler?
- A low water cutoff- prevents boiler from firing if the water level is too low
- Float valve sensor
- Electrical conductivity probe
What type of information should be kept within a boiler log?
- Gage readings
- Water quality
- Chemicals used and doses
- Stack economizer pressure
- PSI
- Conductivity
