What specification requirement must the pour point of diesel fuel meet_________________?
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Answer: A. lower than the coldest atmospheric temperature at which oil is to be pumped
Explanation
The pour point of diesel fuel indicates the lowest temperature at which it flows freely. This temperature must remain lower than the coldest ambient operating environment expected. If ambient temperature drops below the pour point, fuel solidifies and blocks fuel lines. Diesel fuels contain paraffin waxes that crystallize and precipitate at low temperatures. Fuel filters can become clogged with wax crystals if the pour point is too high. Refineries use chemical additives called pour point depressants to improve cold weather performance.
Vehicles operating in winter conditions require specially formulated diesel with low pour points. Blocked fuel systems cause engine stalling and failure in cold weather environments. Storage tanks in cold climates require heating systems if fuel pour points are high. Higher pour points would cause diesel fuel to gel at moderate winter temperatures. Specifications must account for environmental conditions rather than ignoring temperature. Arbitrary high temperature limits like one hundred degrees Celsius are irrelevant for diesel.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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