TRANSMISSION PUMP GROUP 7S6875 - Caterpillar

Rating Conditions
Unless otherwise specified, all ratings are based on SAE J1349 standard ambient conditions:* 100 kPa (29.6 inches of Hg) of pressure* 30 percent relative humidity, and* a temperature of 26°C (77°F)Ratings also apply at ISO8665, ISO3046/1, DIN6271, and BS5514 standard conditions.Power for diesel engines is based on:* API gravity of 35 at 15°C (60°F)* fuel LHV of 42,780 kJ/g (18390 Btu/lb) at 29°C (84°F)* fuel density of 839 g/L (7 lb/US gal)Ratings are gross output ratings- the total output capability of the engine equipped with standard accessories. Standard accessories include pumps for lubrication oil, fuel, and jacket water. The gross output, minus the power required to drive auxiliary components, equals the net power available for the external (flywheel) load. Typical auxiliary components include cooling fans, air compressors, and charging alternators.Rating Definitions
It is important to know how the vessel will be operating, so that the rating can match the operating profile. Additionally, proper rating selection is important so that customer perception of price/value is realized. In selecting a rating for a specific application, the most important consideration is time spent at full throttle. These rating definitions identify the percent of time at full throttle and corresponding times below rated rpm. A (Continuous): For heavy-duty service in ocean-going displacement hull vessels such as freighters, tugboats, bottom drag trawlers, and deep river towboats when the engine is operated at rated load and speed up to 100 percent of the time without interruption or load cycling. Typical use is 5000 to 8000 hours per year. B (Medium Duty): For displacement hull vessels such as mid-water trawlers, purse seiners, crew and supply boats, ferries, and towboats where locks, sandbars and curves dictate frequent slowing when engine load and speed are constant with some cycling. The engine may be operated up to 80 percent load factor and at rated load and speed for up to 80 percent of the duty cycle, or 10 hours out of every 12 hours. Typical use is 3000 to 5000 hours per year. C (Intermittent): For planing hull vessels such as ferries, fishing boats moving at higher speeds out and back (i.e. lobster, crayfish and tuna) offshore service boats, and also displacement hull yachts and short trip coastal freighters where engine load and speed are cyclical. The engine may be operated at up to 80 percent load factor and at rated load and speed for up to 50 percent of the duty cycle, or 6 hours out of every 12 hours. Typical use is 2000 to 4000 hours per year. D (Patrol Craft): For planning hull vessels such as offshore patrol boats, customs, police, and some fire and fishing boats. Also used for bow and stern thursters. The engine may be operated at up to 50 percent load factor and at rated load and speed for up to 16 percent of the duty cycle or 2 hours out of every 12 hours. Typical use is 1000 to 3000 hours per year. E (High Performance): For planning hull vessels