🔍 Key Concepts

• 46 CFR requirements for hydraulic starting systems on diesel engines operating at 150 psi or more • The safety purpose of specifying a minimum flash point for hydraulic fluid • Differences between fire risk properties (flash point, toxicity, oxidation resistance) versus performance properties (viscosity index)

💭 Think About

• Ask yourself: Is the Coast Guard’s primary concern here about engine performance, fire safety, or long-term fluid life? Which of these is most critical at 150 psi or more? • Look at the options mentioning flash point. For a high‑pressure hydraulic system near hot machinery, would regulations more likely require a flash point that is higher or lower, and why? • Consider which options sound like manufacturer preferences versus specific minimum regulatory safety requirements that can be clearly tested and enforced.

✅ Before You Answer

• Confirm in 46 CFR, Subchapter F (Marine Engineering) where hydraulic starting system fluid requirements are listed. • Check whether the regulation specifies a numerical flash point value and whether it is expressed as not less than some temperature. • Verify if the regulation mentions toxicity or oxidation resistance at all for this specific requirement, or if those are handled under different general fluid standards.