Building Systems Operations & Maintenance Flashcards

How often should a reduced pressure zone (RPZ) backflow preventer typically be tested by a certified tester?

Answer: At least annually

Most U.S. water purveyors and plumbing codes require at least annual testing of testable backflow assemblies.

What is the recommended approach to control Legionella in domestic hot water while preventing scalding?

Answer: Store water at about 140°F and use a thermostatic mixing valve to deliver about 120°F

High storage temperatures inhibit Legionella growth, and mixing valves limit fixture temperatures to prevent burns.

Which code is the primary U.S. safety standard for the inspection and maintenance of elevators and escalators?

Answer: ASME A17.1

ASME A17.1, adopted by most jurisdictions, covers elevator and escalator safety, inspection, and testing.

What is the recommended minimum frequency for routine low-slope roof inspections?

Answer: Twice a year, typically spring and fall, plus after severe storms

Semiannual inspections plus post-storm checks catch membrane, flashing, and drainage problems early.

Banging noises in water piping when solenoid valves close quickly are most effectively corrected by which measure?

Answer: Installing water hammer arresters near the quick-closing valves

Water hammer arresters absorb the pressure surge from sudden flow stoppage.

A common rule for scheduling grease interceptor pump-outs is to service the unit when FOG and solids reach what portion of its depth?

Answer: 25%

Many municipal pretreatment programs use the 25% rule to prevent grease from passing into the sewer.

In a closed hydronic heating system, frequent relief valve discharge and wide pressure swings when the boiler fires usually point to which problem?

Answer: A waterlogged or failed expansion tank

A waterlogged expansion tank cannot absorb thermal expansion, so pressure spikes and lifts the relief valve.