Abstract: A fluid jet drilling nozzle and associated drilling method. The nozzle is adapted to be connected to a source of high pressure fluid and to be rotated about a rotation axis, and comprises a body formed so that it partially encloses a cavity, which cavity is in fluid communication with the source of high pressure fluid when the nozzle is connected to such source. The nozzle further comprises means for allowing high pressure fluid in the cavity to exit the nozzle in the form of a high velocity fluid jet which intersects the axis of rotation of the nozzle. Such a nozzle may be mounted in any drilling apparatus capable of supplying high pressure fluid to the cavity and of rotating or oscillating the nozzle about its rotation axis.

Abstract: An electrostatic precipitator is disclosed comprising a series of parallel collector electrode plates of similarly corrugated form, with the continuously curved and successive crests and valleys of the corrugations of each plate positioned in opposition to the similar crests and valleys of the adjacent plates so as to form gas-flow channels that successively converge and diverge, forming alternate narrow and wide regions along the direction of flow between each pair of plates. Of one common electrical polarity, these collector electrode plates cooperate with an array of discharge filament electrodes of opposite common polarity located between each pair of plates, with one such filament electrode centered in and extending longitudinally of each of the wide regions defined between the opposing valleys of the adjacent plates.

Abstract: A method of forming a composite structure having precision surface openings, such as an air foil through which air can be drawn in for boundary layer control. A metallic face sheet is bonded to a base member that is formed with elongate channels which are to serve as air plenums. A protective metal strip is inserted into each channel, and a high velocity water jet is directed against the face sheet at the area of each channel to form a through slot opening. The protective strip protects the base material from the inpact of the water after it passes through the slot being formed.

Abstract: By the action of water jetted against the concrete in systematically controlled manner under ultra-high pressures (i.e. above 25,000 psi) areas of structural concrete are removed to required depths through the one or more levels of aggregate involved efficiently and with safety to the basic structure and to attendant personnel. With this method and apparatus employing an array of such jets scanned progressively back and forth over a work area, the rates at which requisite volumes of hardened concrete can be removed, regardless of condition or state of the concrete and the presence of reinforcing bars, are much greater than those customarily achieved with conventional methods. Moreover the operation can be performed without danger of cutting into and weakening embedded reinforcing bars, without damaging the concrete in adjoining regions, without dust pollution and with minimum noise levels that are also readily shieldable.

Abstract: A pressure intensifying apparatus to deliver a very high pressure stream of water through a nozzle. There is a single working piston having two pressure surfaces of a relatively large area, the working piston being connected to two high pressure pistons each having a pressure surface of a relatively small area. A control valve delivers a high pressure working fluid alternately to opposite sides of the working piston to cause it to reciprocate so that the pressure pistons alternately deliver water at high pressure to the nozzle.

Abstract: A valve assembly especially adapted for use with very high pressure reciprocating pumps. The main components are coaxially aligned. A main high pressure passage extends through the center of the assembly and has check valves at opposite ends thereof. One of the check valves has an annular valve element comprising inner and outer sleeves which fit against one another with an interference fit. This annular valve element seats against a matching annular inlet passage.