Mechanisms Facilitate Blowdown of Large Diesel Engines

Stennis Space Center, Mississippi

Simple mechanisms have been devised to facilitate the blowdown of large diesel engines. As explained below, these mechanisms reduce the amount of time and effort that must be expended to test engines before operating them.

Blowdown is a procedure used to detect fuel or water leaks in diesel-engine cylinders. To prepare for blowdown, a technician opens a valve, known as a Kenny cock, on each cylinder. The engine is then cycled. If fuel or water has leaked into a cylinder, it is ejected through a drain pipe and can be seen. Once blowdown has been completed, the Kenny cocks are closed. If no water or fuel was found during blowdown, the engine can be started.

A Simple Mechanism — similar to a combination of wrench extensions used to turn a difficult-to-reach nut or bolt on an automobile engine — is installed permanently to bring the point of actuation of a Kenny cock out to a readily accessible and visible location.

In the setting for which the present blowdown-facilitating mechanisms were devised, the Kenny cocks are difficult to see and reach, and they are opened and closed by turning hexagonal bolts. Before these mechanisms were installed, technicians had to squat or get down on their knees in order to see, open, and close the Kenny cocks. The combination of difficulty and awkwardness of position contributed substantially to the time and effort of the blowdown procedure and increased the risk of injury.

The blowdown-facilitating mechanisms consist of components attached permanently to the Kenny cocks plus at least one component that a technician carries from cylinder to cylinder. One of the components attached permanently to the Kenny cock on each cylinder is a swivel socket that fits onto the hexagonal bolt. An extension is attached to the swivel socket and is supported by a bracket, through which it protrudes. A hexagonal nut is attached to the end of the extension (see figure).

The component carried by the technician is a T-handle shaft with a hexagonal socket attached to tip of the shaft. The technician simply mates the hexagonal socket with the hexagonal nut and turns the handle to open or close the Kenny cock. Because the hexagonal nut is readily visible, blowdown can be performed in less time and with less difficulty and risk. In the original setting, use of these mechanisms has reduced the time needed to perform blowdown by about 60 percent.

This work was done by Tim Delcuze, Ira Lossett, Todd Pearson, Jerry Quinn, James Seals, Danny Tarter, and Rodney Wilkinson of Lockheed Martin Corp. for Stennis Space Center. For further information, access the Technical Support Package (TSP) free on-line at www.nasatech.com/tsp under the Mechancics category.

Inquiries concerning rights for the commercial use of this invention should be addressed to the Patent Counsel, Stennis Space Center; (228) 688-1929.

Refer to SSC-00132.