S-13 Water Supply and Pressure Requirements 3

Question 1

What is the significance of the 'churn pressure' (shut-off pressure) of a fire pump in relation to standpipe system components?

Accepted Answer

It is the maximum pressure the pump produces at zero flow, which system components must be rated to withstand

Answer

It is the minimum pressure the pump can produce

Answer

It is the pressure set on the pressure relief valve

Answer

It is the pressure at which the pump automatically shuts down

Question 2

Under what condition must a pressure relief valve on a standpipe fire pump be set to open?

Accepted Answer

When pump discharge pressure exceeds a preset maximum to prevent over-pressurization of the system

Answer

When system pressure reaches 175 psi

Answer

When pump discharge pressure exceeds 175 psi at churn

Answer

When the suction tank level drops below 50%

Question 3

What is the minimum city water main pressure required for a street main to be considered an acceptable direct supply for a standpipe system in NYC without a fire pump?

Accepted Answer

As calculated to meet residual pressure at the highest outlet

Answer

20 psi static

Answer

40 psi residual under flow conditions

Answer

60 psi static

Question 4

How often must the fire pump for a standpipe system be tested under flow conditions (annual performance test) per NFPA 25?

Accepted Answer

Annually

Answer

Every 6 months

Answer

Every 2 years

Answer

Every 3 years

Question 5

What is the purpose of a diesel engine-driven fire pump in a standpipe system?

Accepted Answer

To serve as a backup supply in case of electric power failure

Answer

To provide higher flow rates than electric pumps

Answer

To reduce system maintenance requirements

Answer

To automatically reset pressure-reducing valves

Question 6

A standpipe system serving a building more than 300 feet tall typically requires which of the following water supply configurations?

Accepted Answer

A zoned standpipe system with multiple pumps in series or a high-pressure booster arrangement

Answer

A single fire pump and one gravity tank

Answer

City main pressure alone with a jockey pump

Answer

Two jockey pumps operating in parallel

Question 7

According to FDNY regulations, how soon after a standpipe fire pump starts automatically must it be manually stopped if no fire emergency exists?

Accepted Answer

It should be stopped immediately once pressure is restored and the cause investigated

Answer

It must run continuously until the cause is identified

Answer

It must run for at least 10 minutes to prime the system

Answer

It must run until manually reset by FDNY