_____ storage is preferable for boilers that are out of service for an
extended period of time or in locations where freezing temperatures
during the standby are expected. Ans✓✓✓ Dry
______ is particularly harmful as it forms a very hard deposit on turbine
blades. Ans✓✓✓ Silica
________ happens when the pressure at any point inside a centrifugal
pump drops below the vapour pressure of the liquid forming vapour
bubbles and creates cavities in the liquid flow. Ans✓✓✓ Cavitation
________ is the result of dissolved air or oxygen in the feedwater.
Ans✓✓✓ Pitting
_________ explosions occur when a pressure part of the boiler, such as
the steam drum, fails due to steam pressure or a structural weakening of
the metal. Ans✓✓✓ Pressure
_________ is any solid, liquid, or vaporous contaminants that leave the
boiler with the steam. Ans✓✓✓ Carryover
_________ testing involves the pressurization of a vessel with a
compressible gas, such as air or nitrogen, to determine if any leaks are
present. Ans✓✓✓ Pneumatic
,__________ _______ are leak-proof containers that have an internal or
external operating pressure. Ans✓✓✓ Pressure vessels
__________ is the protrusion of weld metal beyond the weld toe that
covers the parent metal surface but has not fused to it. Ans✓✓✓
Overlap
__________ is the term for spherical or tube like defects, cavities, or
voids caused by gases trapped inside the weld or gases that have evolved
to the surface. Ans✓✓✓ Porosity
__________ takes precedence over the ASME BPVC, if a conflict
exists. Ans✓✓✓ CSA-B51
__________ uses area replacement as the basis for reinforcement
calculations. Ans✓✓✓ ASME BPVC
____________ is insufficient weld deposit, which results in a depression
or reduction in the thickness of a groove weld. Ans✓✓✓ Underfill
_______________ is the only arc welding process capable of welding all
commercial ferrous and non-ferrous alloys. Ans✓✓✓ Gas metal arc
welding process (GMAW)
,_________________ are solid non-metallic inclusions entrapped below
the surface in the weld metal, or more often, between deposited weld
metal and the base metal. Ans✓✓✓ Slag inclusions
A _________ feed system involves feeding the chemicals to the boiler
system at the most efficient injection points and at a steady and
continuous rate. Ans✓✓✓ Continuous
A 152.4 mm diameter piping system is 50 m long and contains three
elbows, two gate valves, one globe valve, and two tees. If flow in the
system is 75 L/s, calculate the friction head. Ans✓✓✓ 8.364 m
A 203.2 mm diameter piping system is 75 m long and contains three
elbows, two gate valves, one globe valve, and five tees. If flow in the
system is 75 L/s, calculate the friction head. Ans✓✓✓ 3.58 m
A centrifugal pump may be defined as a pump that uses centrifugal force
to impart energy to a fluid by giving the fluid high _________ and then
converting this into pressure. Ans✓✓✓ Velocity
A centrifugal pump may be defined as a pump that uses centrifugal force
to impart energy to a fluid by giving the fluid high _________ and then
converting this into pressure. Ans✓✓✓ Velocity
A chemical in a storage tank has a relative density of 7.60. What is the
equivalent head at the outlet of the tank where a pressure gauge reads
250 kPa? Ans✓✓✓ : 3.35 m
, A hydrogen zeolite softener is used to remove the scale-forming _____
without the formation of sodium bicarbonate. Ans✓✓✓ Salts
A low gas pressure cut-off switch _______ the burner from operating
when the gas pressure in the supply line drops below the pressure
necessary to maintain a stable flame at the burner. Ans✓✓✓ Prevents
A manufacturer specifies a required NPSH of 5 m for a certain pump. To
satisfy this requirement, what must the minimum pressure be at the
suction of the pump if the liquid being moved is water at 120°C? (note
Vf = 1.0603) Ans✓✓✓ 244.8 kPa
A pressure controller maintains a constant furnace pressure in a boiler
(at all loads) by adjusting the position of the ______ dampers. Ans✓✓✓
Induced draft
A pump is sitting at rest with its discharge valve open and the pressure
gauge showing 210 kPa. The total static head of the pump in this
situation is 11 m. If the pump takes suction from a transfer tank located
4 m above it, what is the current level in the transfer tank? The liquid is
water at 42°C. Ans✓✓✓ : 6.59 m
A rapid increase in boiler load causes an immediate increase in steam
flow from the boiler, which creates a sudden _____ in the boiler steam
drum pressure. Ans✓✓✓ Drop