For the hose used with propane dispensers, the design working pressure and safety factor specified by NFPA 58 is:

For the hose used with propane dispensers, the design working pressure and safety factor specified by NFPA 58 is:

• A. 300 psi 4:1
• B. 400 psi 6:1
• C. 350 psi 5:1
• D. 200 psi 3:1

Answer: (C)

The main idea the question tests is how NFPA 58 sets the design requirements for propane dispenser hoses, specifically the design working pressure and the safety margin. NFPA 58 specifies that hoses used with LPG dispensers are designed to handle a working pressure of 350 psi and must have a safety factor of 5:1. This means the hose must have a burst pressure of at least 1,750 psi (350 psi × 5). The 5:1 margin provides a robust buffer against pressure surges, hose flexing, and other normal conditions that could push pressure higher than the steady operating value, helping prevent failure during use. So the combination of 350 psi design working pressure with a 5:1 safety factor best reflects the NFPA 58 requirement for dispenser hoses. The other options don’t match those NFPA-prescribed values, which is why they aren’t the correct pairing.

The main idea the question tests is how NFPA 58 sets the design requirements for propane dispenser hoses, specifically the design working pressure and the safety margin. NFPA 58 specifies that hoses used with LPG dispensers are designed to handle a working pressure of 350 psi and must have a safety factor of 5:1. This means the hose must have a burst pressure of at least 1,750 psi (350 psi × 5). The 5:1 margin provides a robust buffer against pressure surges, hose flexing, and other normal conditions that could push pressure higher than the steady operating value, helping prevent failure during use.

So the combination of 350 psi design working pressure with a 5:1 safety factor best reflects the NFPA 58 requirement for dispenser hoses. The other options don’t match those NFPA-prescribed values, which is why they aren’t the correct pairing.