Exam (elaborations)
DC Third Testing 2023 Update – Questions & Correct Answers
- Course
- Institution
DC Third Testing 2023 Update – Questions & Correct Answers
[Show more]
Seller
Follow
LeCrae
Reviews received
Content preview
DC Third Testing 2023 Update – Questions &Correct Answers
The component in which liquid vapor by absorbing heat is called? ✔️Ans -
Evaporator
Select the best answer electrical grounding method? ✔️Ans - Metal stake
drive 8 foot into the ground.
A _____ valve should be used for throttling purpose? ✔️Ans - Globe
What is the acceptable range for residual sodium sulfite in the boiler
maintain? ✔️Ans - 30-70
What is the BTU content of a gallon of #4? ✔️Ans - 146,000
What does a zeolite water softener system use as a means of regeneration?
✔️Ans - Brine
What are the 4 steps for a Zeolite Rejuvenation water softener process?
✔️Ans - Back wash
Backwash, brine, rinse, service
Where is medium temperature is liquid found? ✔️Ans - Condenser
Where is high temperature vapor found? ✔️Ans - At the discharge of the
compressor or condenser
What stays are used to support the burner chamber in a scotch marine boiler?
✔️Ans - Diagonal Stays
What type of safety valve is this? ✔️Ans - ( Full) Crosby nozzle-type
safety valve. Page 365 BOG
What type of safety valve is this? ✔️Ans - ( Full) Crosby nozzle-type
safety valve. Page 365 BOG
,Where do you found superheat reading? ✔️Ans - Take suction line
pressure
Cross reference using a P/T Chart
Get tail coil Temperature
Subtract cross references temperature from tail coil temperature
Result will be superheat
Name the wire that connects all component of a system to a physical ground
or water pipe? ✔️Ans - Grounding Electrode Conductor
Where do get sub-cooling reading? ✔️Ans - Take liquid line pressure
Cross reference to temperature using a P/T Chart
Get liquid line temperature
Subtract actual temperature from cross referenced temperature
Result is sub-cooling
On the boilers that have both Quick opening and Screw type blow down
valves, the Quick opening valve must be located? ✔️Ans - Closest to the
boiler and followed by the screw type valve
High pressure boilers equipped with Quick opening and Screw type valves are
blown down how? ✔️Ans - By opening the Quick opening valve first and
closing it Last. Page 403 BOG
ASME Code defines a slow opening valve as what? ✔️Ans - One requiring
at least 5 full 360 degree turns between full open and close position. Page 374
A 300 Horsepower boiler operating at 100psi has an average load of 75% with
80% condensate return and 5% blow down. The treatment provides a
chemical which costs $8.75 per gallon, and will treat 600 gallon. Find the
amount of the chemical needed for the day period, and the cost of the
chemical for a 30 days period? ✔️Ans - Water In = Water Out
Makeup + Condensate Return = Evaporator + Blow Down
Average Evaporator Rate = 300 x 34.5 pph x .75% load = 7762, 50 pph
1 Month + .8( 7762.50 pph) = 7762.50 pph + 0500 m
1 Month + 6210 pph = 7762.50 pph + .0500 m
, -6210 -6210
1 Month = 1552.5 pph + .0500
.9500 m = 1552.5 pph
.9500m .9500
1Month = 1,634.21 pph
Gallons per Month = 1634..33 x 24 x 30 = 141, 252.24 gallons per month
Chemical needed = 141,252.24 gallon / 600 gallon = 235, 40 gallon
Cost per month = 235, 40 gallon x 8.75 = $2,059.75
During a 24 hours operation how often should you check the water level?
✔️Ans - Once per shift
A 15 psi steam boiler produces 8000 pound of steam per hour. The
Minimum pipe size for the pipe leaving the boiler is___12__inches.
(Density is 0.037 lbs/ft3)
Equation: ✔️Ans - D = 12 (C/d/h /.7854)
D = 12 (.037/60) = 3,603.60
D = .ft = 3,927
D = 3.603.,927 = 0.917647058
D = 0.957938963 * 12
D = 11.49 OR 12 "pipe
The boiler steam line is 350 Feet long. During start-up the pipe is heated
From 60 F to 350 F. The 350 F. The pipe wills expand__7.92__inches
Due to the change in temperature
Equation: ✔️Ans - (T 1 - T2) x L x .0000065
(350 - 60) x 350 x .0000065
290 x 350 x 12 x .0000065 = 7.92
A 12" pipe filled with water to a height of 250 feet will have a pressure of
_________at the bottom of the pipe?
Equation:
P = FT / 2.31 ✔️Ans - 250 feet / 2.31 = 108.22
A "5" pipe filled with water to a height of 75 feet will have a pressure of
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller LeCrae. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $19.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
67866 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now