VALVE GP-PILOT RELIEF 1057459 - Caterpillar

It is important to know the way that a vessel will be operated. This is important because the rating needs to match the profile. Additionally, a proper rating selection is important because this selection affects the customer's perception of price (value).In selecting a rating for a specific application, the most important consideration is the time that is spent at full throttle. These rating definitions identify the percent of time at full throttle and corresponding times below the rated rpm.The following list of ratings are for planing hull vessels:C (Intermittent) - Rating C is for the following types of vessels: ferries, fishing boats (lobster boats, etc.) that move at higher speeds out and back and offshore service boats . C rated vessels also include displacement hull yachts and short trip coastal freighters that operate cyclically with both engine load and speed. The engine may be operated at a load factor up to 80 percent. This is at a rated load and at a rated speed up to 50 percent of the duty cycle (6 hours out of every 12 hours). A typical use is 2000 to 4000 hours per year.D (Patrol Craft) - Rating D is for the following types of vessels: offshore patrol boats, customs, police and some fire and fishing boatsD rated vessels are also used for bow and stern thrusters. The engine may be operated up to 50 percent load factor. This is at rated load and at a rated speed up to 16 percent of the duty cycle (2 hours out of every 12 hours). Typical use is 1000 to 3000 hours per year.E (High Performance) - Rating E is for the following types of vessels: pleasure craft, harbor patrol, harbor master craft and some fishing boats and pilot boatsThe engine may be operated up to 30 percent load factor. This is at rated load and speed up to 8 percent of the duty cycle (1/2 hour out of every 6 hours). Typical use is 250 to 1000 hours per year. The above rating definitions ensure the customer obtains an acceptable and competitively priced match between initial cost and total life and lifetime costs. Increased engine wear and higher maintenance costs will occur when you constantly operate a vessel for more time at full throttle than the designated rating.
Operating engines above the rating definitions can result in shorter service life before overhaul.
For most applications, the customer can provide profile information from similar vessels or from the actual vessel, if the vessel is being repowered. Note: If such information does not sufficiently indicate the operating profile, instruments are available to more precisely define engine operation. A 7D-1513 Tachograph Assembly can establish an operating profile. The tachograph records engine speeds versus time on a paper chart.Available Ratings
The ratings for the 3408 High Performance Marine Engine are at 2300 rpm. These ratings are available in electronically governed arrangements only:
Table 1
3408C High Performance Marine Engines
Electronically Governed Arrangements
Rating kW (hp)
C 448 kW (600 hp)
D