Abstract: A method for improved penetration of a work material using a high velocity fluid jet from a nozzle element by providing a sealed chamber between a surface of the work material and the nozzle element is described. With hard and/or irregular materials, a deformable element is provided between the nozzle element and the work surface so that the deformable element conforms to the surface to effect the seal. A preferred nozzle element assembly including the deformable element is also described. The method is particularly adapted to mining operations such as coal, hard rock excavation, and wood impregnation.

Abstract: A novel system for metering a relatively viscous fluid into a less viscous fluid using a centrifugal pump is described. In particular, a novel valve for use in the system including a fluid pressure responsive means to actuate a needle valve which is slideable into an orifice for control or metering of the viscous fluid is described. The valve meters decreasing small amounts of the viscous fluid in direct relation to the increased pressure developed at the delivery end of the centrifugal pump because of the selection of the angle of the point of the needle and its relationship to the orifice. The system is particularly adapted to metering viscous polymer containing fluids, including microdispersions of polymers as solutions or true solutions into water in very small amounts thereby reducing friction and increasing fluid flow in delivery conduits such as fire hoses and the like.