NIULPE Class 5 case studies
NIULPE Class 5 · Put your knowledge to work in context.
The NIULPE Class 5 Engineer credential is an entry-level licensing classification issued through the National Institute for Uniform Licensing of Power Engineers, a US organization that writes uniform power engineer examinations used by participating state and municipal licensing authorities. It is aimed at people entering boiler-room and plant work - junior firemen, boiler operators, maintenance helpers, and building engineers moving from general facilities work into steam or hot water plant operation - who need a credential showing basic competence before accumulating the operating experience required for higher classes. The NIULPE Class 5 case studies are 5 cases and about 2,876 words.
1Jumped Low-Water Cutoff During a Cold Snap
A 200 hp, 15 psig firetube steam boiler supplies a school campus during a January cold snap. The boiler is equipped with a probe-type low-water fuel cutoff and a separate gauge glass.
695 words, about 3 min2Intermittent Flame Failure After Scanner Replacement
A 600 hp firetube boiler fires natural gas through a forced-draft, modulating burner. After a contractor replaced the flame scanner and cleaned the burner, the boiler locks out on flame failure about one start in four.
583 words, about 3 min3Water Hammer on a Cold Steam Main
An 8-inch, schedule 40 saturated steam main at 150 psig supplies a process building through a 300-foot run. The main has drip legs at 100-foot intervals, each with an inverted-bucket trap and a bypass valve.
544 words, about 3 min4Carryover and Softener Failure at Peak Load
A 100 psig firetube boiler produces 20,000 lb/h of saturated steam. The makeup water is softened but the softener has been off-line for two days; raw water hardness is 180 mg/L as CaCO3.
541 words, about 3 min5Feedwater Pump Cavitation at High Fire
A deaerator operates at 5 psig and supplies 230°F feedwater to a centrifugal boiler feed pump. The pump centerline is 8 ft below the deaerator outlet, and the suction line is 4-inch with a clean strainer pressure drop of 2 psi and piping friction of 1.5 psi.
513 words, about 3 min