Abstract: A method of repairing a defective portion of a tube which is one of a plurality of generally parallel elongated tubes includes severing an axial portion of the tube which contains a defective portion, bending the free end portions of the tube disposed adjacent to where the axial portion which was severed, and securing an insert tube to the free end portions of the tube disposed adjacent to where the removed axial portion was located to thereby establish a passage for free flow of fluid within the repaired tube. In a preferred embodiment of the invention, the free end portions will be bent in substantially the same direction about 20 to 60 degrees with respect to the longitudinal axis of the tube when the tube being repaired is part of a water wall of a fossil fuel fired boiler and the repair is effected from the cold side thereof.

Abstract: Effective supervision of the road speed of a diesel truck requires termination of the operation of the engine when the truck is operated at an excessive speed. Utilizing to advantage what is already available, namely an engine shut-down control when the engine lubricating oil pressure is below a specified pressure, the device hereof provides the referred to road speed supervision in an effective manner and with minimum expense and complication. Specifically, the within road speed control contemplates creating an "artificial" loss of lubricating oil pressure, i.e. one that is not due to an actual defect or malfunction of the lubricating oil circulating system, but rather one that is responsive to the operation of the truck at an excessive speed. Said "artificial" loss of lubricating oil pressure is, of course, just as effective as an actual pressure loss in causing engine shut-off or slow-down, thereby providing effective road speed supervision for the diesel truck.

Abstract: A valve in the fuel line of an internal combustion engine of the type which is normally biased to its closed position, causing engine shut-down, but prevented by an opposing oil pressure from doing so; the valve, in effect, therefore being one which promotes engine shut-down in the event of failure in the engine oil pressure. As an improvement to this class of valves, of which the within valve is a significant contribution, the valve has an engine shut-down function related not merely to the required oil pressure at engine start-up, but also to required oil pressures at full power speed as well as intermediate power speeds throughout its contemplated range of operation.