EJECTOR PUMPS

The advantages of EPs, which give impetus to their wide use in fuel systems of aircraft and helicopters, are the following:

• simple design and total exclusion of moving elements;
• small overall dimensions and weight;
• self-priming properties;
• durability (operational life is practically equal to the lifetime of an airframe);
• easy operation;
• low manufacturing and operation cost;
• absence of routine maintenance;
• maximum explosion and fire safety;
• complete fuel depletion from tanks and corresponding increase of flight range;
• increase of aircraft durability due to the absence of necessity for access doors.

The high degree of reliability and the absence of routine maintenance make EP the only type of pumps which can be mounted in places without access during aircraft operation, while small dimensions, especially throughout the height, make EP the only possible type of a pump for placement in fuel tanks with small height, for instance, widely used nowadays integral wing tanks.

Self-priming properties of EPs enable to use them when it is necessary to pump out the remaining fuel from places where mounting of another type of pump is impossible.

The SN-3F, SN-5, SN-6, SN-7, SN-11, SN-12, SN-13, SN-14 and SN-15 ejector pumps and modifications of some of them developed by Kristall Design Bureau are designed to pump over fuel from one tank into another and from the storage tanks into the feeder tank, including fuel remains, with delivery rates ranging from 500 to 60,000 l/h.