Ch. 5 Flashcards
1
Q
- List the trap selection criteria for the application?
1) Condensate capacity, under start-up
2) Condensate capacity, under normal operating
3) Condensate temperature the trap will have to handle
4) Steam header temperature
5) Pressure differential across the trap
6) The location of the trap
a. 1, 3, 4, 5, 6
b. 1, 2, 3, 4, 5, 6
c. 1, 2, 3, 5, 6
d. 1, 2, 3, 4
e. 5, 6
A
b. 1, 2, 3, 4, 5, 6
2
Q
- Find the warm-up load in kg/h in warming up 50 m of 203.2 mm, Schedule 40 steel pipe to a working pressure of 1737 kPa in a warm-up time of 20 minutes. Initial temperature of the pipe is 20°C. Table 1 lists the dimensions and the mass per meter of different sizes of steel pipe with varying wall thickness.
a. 500 kg
b. 102.89 kg
c. 58 kg
d. 1002.89 kg
A
b. 102.89 kg
2
Q
- In order to determine the correct size of the trap for an application, it is necessary to calculate the condensate load to be removed by the trap, per hour.
a. True
b. False
A
a. True
3
Q
- If a group of traps drain into a common return header, a check valve should be installed between the trap and the supply header.
a. True
b. False
A
b. False
4
Q
- In order to accomplish this warm up in 20 minutes, the condensate rate /h would be:
a. 308.67 kg/h
b. 125 kg/h
c. 254 kg/h
d. 132 kg/h
A
a. 308.67 kg/h
4
Q
- To have a single trap for two units is permitted, as long as the trap capacity is not exceeded.
a. True
b. False
A
b. False
5
Q
- In some systems where the temperature from one condensate stream is ___________ than ______________, a small ____________________ is used to ________ the cooler condensate.
a. much cooler, another stream, steam heat exchanger, heat up
b. hotter, water, steam injection, change
c. colder, steam, temperature gauge, measure
d. smaller, the other, time count, blend
A
a. much cooler, another stream, steam heat exchanger, heat up
5
Q
- The most positive method to test a trap to ensure it is working is to touch the body of the trap.
a. True
b. False
A
b. False
6
Q
- The proper design of the trap and condensate return system is critical in preventing water hammer in a condensate system.
a. True
b. False
A
a. True
6
Q
- Describe three tasks done on a yearly trap inspection.
A. The trap body and operating parts should be examined for corrosion, erosion, mechanical wear, etc
B. All internal parts should be cleaned and worn valves, seats, levers etc., should be replaced, as should cracked
buckets, floats or bellows
C. Check trap housing temperature
D. All gasket seating surfaces should be thoroughly cleaned and new gaskets used on reassembly
a. A, B, C, D
b. A, B
c. A, B, D
d. D
A
c. A, B, D
7
Q
- List three purposes of insulation.
1) Retains the heat in the hot lines
2) Protects the metal surfaces from rust
3) Prevents the temperature inside the power plant building from becoming uncomfortably high
4) Insulating of hot pipelines will prevent injury to personnel due to contact with the bare surfaces of the
pipe.
a. 2, 3, 4
b. 1, 2, 3
c. 1, 3, 4
d. 1, 2, 4
A
c. 1, 3, 4
7
Q
- If a lift is used, then the most common type of trap used is the Thermostatic trap.
a. True
b. False
A
b. False
8
Q
- What type of insulation will most likely be used for HP steam piping?
a. Fiberglass
b. Cloth
c. Calcium silicate
d. Refractory fiber
A
c. Calcium silicate
8
Q
- What checks will be made to ensure a line is completely drained of condensate?
A. Make sure that the line is completely blocked in at both ends
B. Slowly open each low point drain on the steam line. Be sure the drain lines are free and clear of any blockage
C. Open downstream flange
D. Check that each trap is in service
E. Ensure all condensate has been drained from the pressurized side of the steam supply valve
a. A, B, D, E
b. A, B, C, D, E
c. A, B, E
d. A, B
A
a. A, B, D, E
9
Q
- The coefficient of thermal conductivity of a material is a measure of the amount of heat that will be transmitted through this material. Therefore, the higher the value of thermal conductivity for a material, the better will be its insulating ability.
a. True
b. False
A
b. False
