NIULPE 2nd Class case studies

NIULPE 2nd Class · Put your knowledge to work in context.

The NIULPE Second Class Engineer credential is a professional certification for power engineers who operate and supervise high-pressure steam plants. It is typically pursued by candidates who already hold a lower-class license and are ready to take on greater responsibility for boiler safety, plant efficiency, and crew supervision. The NIULPE 2nd Class case studies are 5 cases and about 5,588 words.

Restart of a Laid-Up Firetube Boiler: What Actually Bars Firing Tonight?

A 350 hp natural-gas firetube boiler, MAWP 150 psig, has been in wet layup for 14 months while the plant finished a district-heat tie-in. It must be back on line before the winter peak.

1,067 words, about 5 min 2

High CO at Low Fire After a Burner Linkage Replacement

A 700 hp, 150 psig gas-fired D-type boiler was retuned last week after the burner linkage was replaced. It now passes its annual efficiency test at high fire, but at low fire a portable analyzer reads 7.5% O2 and 1,100 ppm CO (dry), and the flame scanner signal swings between 4 and 9 VDC.

1,003 words, about 5 min 3

Feed Pump Cavitation and Poor Deaeration After a Load Expansion

Three 150 psig boilers share a 5 psig deaerator feeding a pair of horizontal centrifugal feed pumps rated 350 gpm at 480 ft head, with NPSHr of 8.0 ft at rated flow. The pumps sit on a mezzanine whose suction flange is 8 ft below the deaerator's normal water level; the low-level alarm is 24 in.

1,078 words, about 5 min 4

Thrust Bearing Temperature Rise on an Extraction-Condensing Turbine

At 10:40 the thrust bearing metal temperature on a 12 MW, 900 psig/900°F extraction-condensing turbine began climbing from a steady 198°F, reaching 236°F at 11:15. The alarm is 230°F and trip is 250°F.

1,206 words, about 6 min 5

Economizer Justification for a Cycling Gas-Fired Boiler

A plant is evaluating a bare-tube economizer for a 150 psig natural-gas boiler that averages 25,000 lb/h of steam over 6,000 operating hours a year. Feedwater is 105°F from a softener and surge tank; there is no deaerator.

1,234 words, about 6 min