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Flashcards in Steam Traps Deck (20)
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0

What causes air to be drawn back into a steam system during operation?

The pressure in the system drops below atmospheric pressure

1

How much back pressure should be expected against traps discharging directly to atmosphere, or into a dry gravity return line

None

2

What is the designation of a system in which the return lines carry both condensate and gases to a receiver tank?

Dry return

3

What term is used to describe the result of a high velocity slug of water striking an obstruction in a steam line?

Water hammer

4

What is usually an indicator that there is a need to re-examine the trap situation?

Repairs are required too frequently

5

What actuates the control element to open a thermostatic trap

Temperature of the fluid flowing to the trap

6

Which trap combines the air handling capabilities of a thermostatic vent with the condensate handling ability of a float trap?

Float and thermostatic

7

What is the safety factor used to calculate a trap capacity?

Two times the rated capacity of the heat exchanger

8

What is most affected by the difference in pressure existing across the orifice of a trap?

Rate and flow

9

Which trap is recommended for the end-of-main service on low pressure steam system?

F&T

10

What valves and fittings are required ahead of the trap when installing an F&T trap station?

Gate valve, strainer and union

11

Where should the discharge from the trap enter the condensate return lines?

Into the top of the return lines

12

How much pressure differential is required before an inverted bucket trap will cycle properly?

14kPa (2psi)

13

What should be installed if a trap has to push condensate up a riser to a return line?

Check valve downstream of the trap

14

What is the piping configuration used to collect condensate from a main called?

Drip point or drip leg

15

What is the minimum size of drip leg that should be used on an 8" NPS main?

100mm (4")

16

What is a valve on a strainer used for?

To blow down the strainer

17

What is the most accurate method of determining how well the trap is functioning ?

Observe the discharge from a test tree connection downstream of the trap

18

What does an unusual lack of heat output from a single steam heating unit indicate?

Failure of the trapping system to remove the condensate

19

What causes the sensors to signal the lack of condensate immediately ahead of the trap in a conductivity sensor?

The presence of steam or air at the level of the contacts