Abstract: Disclosed is an improved back flash preventing device for a powder spray torch wherein the improvement comprises a structure constructed to thwart attempts by the user to block the outlet end or atmosphere vent of the back flash preventer. This is accomplished by providing the outlet of the vent with a guard so constructed as to prevent the user closing the outlet with his finger, a covering tape or the like.

Abstract: Provided by this invention is an improved apparatus for controlling the rate of flow of fluent material by aspiration into a stream of pressurized gas by regulating the gas pressure downstream from the point of admission of the fluent material thereinto independently of the gas pressure at its source. One regulator regulates the gas pressure and velocity prevailing in a gas and fluent material mixing chamber downstream from a fluent material aspirator and the other regulator regulates the gas pressure closely adjacent the downstream end of the fluent material aspirator. Each regulator can be adjusted to vary the flow of fluent material into the gas stream without need for varying gas flow conditions upstream from the fluent material aspirator.

Abstract: Disclosed is a powder container for a flame spraying torch having an outlet normally closed by an elastomeric plug provided with inner and outer closely spaced diaphragms. The outer diaphragm has an aperture sized for a wiping fit with a powder dispensing tube as the latter approaches and opens a normally closed slit crosswise of the inner diaphragm thereby safeguarding against the loss of powder during both insertion and withdrawal of a powder dispensing tube through the two diaphragms. The powder dispensing tube has an inlet end upstanding axially within a well sized for telescopic assembly about the dispensing end of the powder container.

Abstract: There is provided an improved powder flame spraying apparatus and method having a preheating nozzle in advance of a plurality of final heating nozzles into the converging flame envelopes of the latter of which hardfacing powder is dispensed. This powder is aspirated into a pressurized stream of inert gas at a variable rate readily adjusted between maximum and no-flow by selectively regulating the gas pressure at and/or spaced downstream from the outlet of the powder aspirator. Regulation of the gas pressure is achieved by venting variable quantities of gas to the atmosphere or air to the aspirator outlet as appropriate to provide a desired powder flow and to achieve a desired volume and velocity of gas and powder delivery into the final heating flames.