Exam Prep Pt 2 Flashcards
(60 cards)
When a discharge valve Is
opened to the atmosphere, the pressure on the upstream side of
the valve will:
decrease, and the pressure on the
downstream side will remain the same.
When comparing a globe valve
and a gate valve in the same
application, the gate valve has a
________pressure drop when
fully opened and is the
_________choice for throttling.
lower: poorer
Which of the following is not a
function of a non-return valve?
opens automatically if the boiler operating pressure drops below the header pressure
Which one of the following
statements is the generally
accepted method to verify at the
local level that a manual valve is
fully closed on a static piping system that is in the depressurized condition?
As an operator you would attempt to turn the handwheel in the closed direction and verify no movement.
Which of the following types of
similarly sized valves in an
operating water system produces
the least frictional head loss
when fully open?
Ball valve
After an adjustment of the
packing gland on a valve that had
a minor packing leak, the operator attempts to operate the
valve but finds it stuck. What is the most probable cause?
The operator overtightened the packing, causing the stem to bind.
What would the valve
position be if the valve actuator
experiences a reduction in air
pressure caused by a leaking air connection?
More Closed
Which of the following types of
similarly sized valves requires the
most manual valve stem rotation
to move the valve from fully open
to fully closed? (Assume that
each valve has a non-rising stem.)
Gate valve
What pressure must be exceeded
in order for a high-pressure valve
to open
125 psi
The ASME Code states that
before bringing a high-pressure boiler online, it must be warmed-up. Assuming all conditions are
normal, what is common practice regarding closing of the vent
valve?
close the vent when the
pressure gauge reads 25 psi
Which of the following is a
generally accepted method for
locally verifying that a manual
valve is fully closed in a
depressurized static piping system?
Attempt to turn the valve hand wheel in the fully closed direction and verify no movement.
The purpose of backseating a
manual valve in an operating
system is to:
isolate system pressure from the packing stuffing box to minimize packing leakage.
In a cooling water system when
comparing a 3-inch gate valve to
a 3-inch globe valve used for the
same application in the process, which statement below is correct
if both valves were fully open?
The globe valve produces the larger head loss and the smaller flow
rate.
The voltage of an ignition transformer is created and travels to
electrodes. What holds and protects the electrodes in place?
the electrodes are held in
place by the porcelains.
What are the two elements in
fuel oil that produce most of its
heat?
carbon and hydrogen
What would a high pressure
differential across a fuel oil
strainer set indicate?
a dirty fuel oil strainer
What is the Btu content of natural
gas?
100,000 Btu/therm
You are installing a boiler
according to the boiler rules and regulations. Where must the filter
and strainers for oil fired boilers
be installed?
Upstream from the safety
shut off valve
Which of the following, best defines the ratio of the total heat
supplied by the fuel to the total
heat absorbed by the boiler
water?
thermal efficiency
The term viscosity can best be
defined as:
the point at which oil starts to flow
Which formula would you use to
calculate the Btu/lb heat content
of fuel oil?
17,687 + 577 x API @ 60
degrees F
The viscosity of fuel oil is lowered by
reducing its temperature. True or False
False
What type of oil burner provides
atomization without the use of
steam or air?
the pressure-type burner
In the ignition system on an oil
burner, what causes the spark to jump the gap and ignite the fuel?
a high voltage spark of 10,000 VDC produced from the transformer, jumps the gap between the electrode tips.
