BLACK SEAL CORE MAIN EXAMS QUESTIONS AND
ANSWERS SURE A+
✔✔Where is caustic embrittlement most likely to occur? - ✔✔on a riveted joint below the
water line
✔✔On a pH scale what number would represent the most acidic of a solution of
feedwater? - ✔✔The most acidic would be 0.
✔✔In a boiler plant system, what is the measure of the degree of acid or base of a
solution called? - ✔✔This would be called the pH level
✔✔What should new or re-tubed boilers be cleaned with? - ✔✔an alkaline detergent
solution
✔✔Which of the following would cause scale to form in a low-pressure boiler? -
✔✔Calcium and magnesium
✔✔As solids and alkalinity in boiler water increase: - ✔✔waterside scaling is increased.
✔✔What chemical would be used to control scale in a low-pressure boiler? -
✔✔Phosphate
✔✔What will excessive oxygen in the boiler water cause to take place? - ✔✔pitting of
boiler metal
✔✔By N.J.A.C. 12:90 rules, what is the minimum thickness allowed for atmospheric
type blowdown tank? - ✔✔5/16 inch
✔✔In the State of New Jersey, when is it permissible to have only one bottom blow off
valve on a boiler? - ✔✔when the MAWP does not exceed 100 psi
, ✔✔N.J.A.C. 12:90 requires that sewer lines be protected from high temperatures and
pressure coming from boiler blow-off lines. What device is used for this purpose? - ✔✔a
blowdown tank
✔✔What effect would frequent blowing down of a boiler have on the system? - ✔✔blow
down heat loss
✔✔The maximum size of the bottom blowdown line and the surface blowdown line is: -
✔✔2.5"
✔✔As the firing rate increases in a boiler equipped with a convection type superheater,
the steam temperature: - ✔✔increases
✔✔Before a hydrostatic test is performed on a boiler, each safety valve should be: -
✔✔held to its seat by means of a testing clamp
✔✔What boiler should never be subjected to an accumulation test? - ✔✔a boiler
equipped with a superheater
✔✔What is the difference between the set-point pressure at which a safety valve opens
and the pressure at which this valve closes called? - ✔✔Blowdown
✔✔What is the function of a dry pipe in a boiler? - ✔✔to remove moisture from the
steam drum
✔✔What part of a safety valve is used to ensure the valve seats properly? - ✔✔the
guides and bushings
✔✔A safety valve data nameplate suggests that the orifice opening on the valve is 1.5
inches w/ a set pressure of 98 psig. What's the total force acting on the valve? - ✔✔173
lbs
✔✔If a boiler has an operating pressure of 345 psi and a 2 1/2-inch diameter safety
valve, what is the total force acting on the safety valve? - ✔✔1,693.5 lbs
✔✔If one atmosphere is about 14.7 psia what is the standard barometer reading at sea
level equal to? - ✔✔760 mm. Hg
✔✔If steam were reduced by a PRV from 500 psi to 125 psi, the steam at 125 psi would
have: - ✔✔the same heat as at 500 psi
ANSWERS SURE A+
✔✔Where is caustic embrittlement most likely to occur? - ✔✔on a riveted joint below the
water line
✔✔On a pH scale what number would represent the most acidic of a solution of
feedwater? - ✔✔The most acidic would be 0.
✔✔In a boiler plant system, what is the measure of the degree of acid or base of a
solution called? - ✔✔This would be called the pH level
✔✔What should new or re-tubed boilers be cleaned with? - ✔✔an alkaline detergent
solution
✔✔Which of the following would cause scale to form in a low-pressure boiler? -
✔✔Calcium and magnesium
✔✔As solids and alkalinity in boiler water increase: - ✔✔waterside scaling is increased.
✔✔What chemical would be used to control scale in a low-pressure boiler? -
✔✔Phosphate
✔✔What will excessive oxygen in the boiler water cause to take place? - ✔✔pitting of
boiler metal
✔✔By N.J.A.C. 12:90 rules, what is the minimum thickness allowed for atmospheric
type blowdown tank? - ✔✔5/16 inch
✔✔In the State of New Jersey, when is it permissible to have only one bottom blow off
valve on a boiler? - ✔✔when the MAWP does not exceed 100 psi
, ✔✔N.J.A.C. 12:90 requires that sewer lines be protected from high temperatures and
pressure coming from boiler blow-off lines. What device is used for this purpose? - ✔✔a
blowdown tank
✔✔What effect would frequent blowing down of a boiler have on the system? - ✔✔blow
down heat loss
✔✔The maximum size of the bottom blowdown line and the surface blowdown line is: -
✔✔2.5"
✔✔As the firing rate increases in a boiler equipped with a convection type superheater,
the steam temperature: - ✔✔increases
✔✔Before a hydrostatic test is performed on a boiler, each safety valve should be: -
✔✔held to its seat by means of a testing clamp
✔✔What boiler should never be subjected to an accumulation test? - ✔✔a boiler
equipped with a superheater
✔✔What is the difference between the set-point pressure at which a safety valve opens
and the pressure at which this valve closes called? - ✔✔Blowdown
✔✔What is the function of a dry pipe in a boiler? - ✔✔to remove moisture from the
steam drum
✔✔What part of a safety valve is used to ensure the valve seats properly? - ✔✔the
guides and bushings
✔✔A safety valve data nameplate suggests that the orifice opening on the valve is 1.5
inches w/ a set pressure of 98 psig. What's the total force acting on the valve? - ✔✔173
lbs
✔✔If a boiler has an operating pressure of 345 psi and a 2 1/2-inch diameter safety
valve, what is the total force acting on the safety valve? - ✔✔1,693.5 lbs
✔✔If one atmosphere is about 14.7 psia what is the standard barometer reading at sea
level equal to? - ✔✔760 mm. Hg
✔✔If steam were reduced by a PRV from 500 psi to 125 psi, the steam at 125 psi would
have: - ✔✔the same heat as at 500 psi
