UTB10 Steam Distribution Systems Flashcards
In a two-pipe vapor system with a return trap, the bottom of the trap should be how many inches above the boiler waterline?
18”
The exterior distribution system is divided into what two systems?
Underground and aboveground
The utilidor type of steam distribution system is part of what distribution system?
Underground
(True or False) The frost line is the lowest depth that the ground freezes during the coldest part of winter.
True
Insulation associated with the conduit type of steam distribution CANNOT be installed in which manner
A. Directly to the pipe
B. Attached to the inner surface of the conduit
C. Packed between the pipe and conduit
D. Directly to the conduit
D. Directly to the conduit
Why is the bottom of the trench filled with broken rock when dealing with the conduit type distribution system?
Adequate water drainage
What material is used to construct the utilidor type distribution system?
Brick or concrete
What is the main drawback of an overhead distribution system?
High cost of maintenance
Which of the following is NOT a classification factor when considering an interior steam distribution system? A. Pipe arrangement B. Accessories used C. Air expulsion method D. Pipe size
D. Pipe size
In a gravity, one-pipe, air-vent system, the return of condensate depends on what factor?
Hydrostatic head
The necessary internal drainage in a gravity, one-pipe, and air-vent system can be obtained by sloping the piping in what manner?
1/4 of an inch for every 10 feet of pipe
What interferes with the proper drainage of water from a radiator that is part of a gravity, one-pipe, and air-vent system?
Partial opening of main steam stop valve
Incorrectly pitched mains located in gravity, one-pipe, and air-vent systems cause what condition?
Uneven heat distribution
What trap permits the flow of condensate and air from the radiator installed in a two-pipe vapor system with a return trap?
Thermostatic
Which valves shut and open when the return trap float starts to rise?
Air vent shuts and steam valve opens.
What type of pump is used in the two-pipe vapor system with a condensate pump?
Centrifugal
At what section of a condensate pump does the return main terminate in a two- pipe vapor system?
Receiver end
Which system is the most practical and trouble-free?
Two-pipe vapor system with condensate pump
Which is NOT a possible cause of an entire distribution system’s failure to heat in a two-pipe vapor system with a condensate pump? A. Flooded return line B. Open receiver vents C. Lack of pump capacity D. Air binding the system
B. Open receiver vents
closed receiver vents cause an entire system to fail.
How many inches of water must be maintained in the vacuum pump in a two-pipe vapor system with a vacuum pump and condensate return line?
3-10”
Steam radiators are classified into how many categories?
2
fin-tube radiator
cast-iron radiator
(True or False) Cast iron radiators are similar to those used in hot-water heating systems.
True
Where is the manual vent installed on a cast iron radiator?
Same spot as an automatic vent
How many steam traps are associated with steam distribution systems utilized by the Seabees?
7
(1) float
(2) bucket thermostatic
(3) float thermostatic
(4) impulse
(5) thermodynamic
(6) throttling
(7) bimetallic element
When using a ball-float trap, where is the condensate returned to?
Feedwater system
Which indication identifies a bucket trap leaking steam?
Excessively hot condensate return line
What is another term used for the thermostatic trap?
Radiator trap
The pressure on the discharge side of the impulse trap should not be over what percentage of the inlet pressure of the trap?
25%
Thermodynamic traps are constructed out of what material?
Stainless steel
How is the rate of flow of the condensate adjusted when using a throttling trap device?
Raising or lowering needle valve.
What happens when the bimetallic strip in the bimetallic-element trap is heated?
Bends
How are dirt and sediment removed from traps?
Blowdown of traps is conducted
Which condition indicates a defective valve operation?
Continuous steam blow
What can be installed to compensate for differences between the demand and supply of water?
One or more water tanks
What type of trap is usually installed inside a water tank to allow condensate to drain into the return line?
Float thermostatic
What two types of steam-operated water heaters are utilized?
Storage and instantaneous
According to safety regulations, the hot water in steam heaters will not exceed how many degrees?
180°F
What temperature-regulating element controls the temperature in steam water heaters?
Valve
What is the bulb and copper tube assembly called in a temperature- regulating device?
Capsule and capillary tube
What is the temperature range on a gauge installed on a hot-water tank?
40°F to 210°F
At what pressure is the relief valve set at on a hot-water heater?
10 pounds higher than operating pressure
How many expansion joints are associated with steam distribution systems?
5
(1) slip joint
(2) bellows joint
(3) swing joint
(4) expansion loop
(5) ball joint
Ball joint expansion type joint allows for how many degrees of flexibility?
30° to 40°
(True or False) Expansion loops require little maintenance except inspection for alignments and leaks.
True
