Abstract: A color changer has a common feed passage that is connected to two or more inlet passages. The common feed passage can be reverse purged in a direction that is opposite a direction of powder flow through the common feed passage. A valve element seals a supply port that connects the inlet passage to the common feed passage to eliminate dead space and form a near bore line seal. The valve element is an elastic material that expands in response to applied compressed air inside the valve element.

Abstract: A powder spray gun includes a powder flow path inlet and a powder flow path outlet, the powder flow path inlet being connectable in a first configuration to a dilute phase powder pump and in a second configuration to a dense phase powder pump, wherein the powder spray gun comprises a spray nozzle that is the same for the first and second configurations. The powder flow path is provided by a powder tube that extends through the gun, with the powder tube having a first diameter at an inlet portion of the spray gun and a second diameter at an outlet portion of the spray gun, with the second diameter being greater than the first diameter. The powder flow path may also include a conical transition portion, and a member for adding air to the powder flow.

Abstract: A selectively configurable spray gun may include a gun body comprising a selectable forward section and a rearward section. The rearward section may be connected with either of two or more selectable forward sections so as to selectively configure the spray gun to operate either with a dense phase powder supply configuration or a with dilute phase powder supply configuration. The rearward section may include a selectable powder flow path that is connectable at an inlet end to a source of dense phase powder and at an outlet end to a selectable spray nozzle in the selectable forward section that may optionally include a diffuser. An adapter may be used to connect the rearward section with a selectable spray nozzle or air cap. A manual spray gun embodiment is also presented. A selectively configurable spray gun for use with a dense phase powder supply may include a smaller diameter powder tube that extends through a larger diameter powder tube.

Abstract: A feed center for powder coating material includes a hopper, an extraction duct, and a control valve. The hopper is connectable in fluid communication with a fluidizing pressure source. The extraction duct is connectable in fluid communication with at least one suction source. The control valve connects the extraction duct with an extraction port of the hopper. The control valve is operable between a first position for applying suction from the at least one suction source to the hopper, and a second position providing an exterior opening in at least one of the control valve and the first extraction duct for exhausting pressurized fluid from the hopper and/or collecting at least some of the air and powder that is exhausted from the powder.

Abstract: A diagnostic apparatus for a powder coating material pump includes a detector that uses pressure or flow to detect a fault in the pump, the diagnostic apparatus being external the pump, internal the pump or a combination of external and internal the pump. Another diagnostic device is provided for a powder coating material pump, and includes a light source in close proximity to the pump, the light source having an on condition and an off condition wherein one or both of the on condition and off condition provides information about the pump performance. An exemplary pump is a dense phase powder coating material pump.

Abstract: A dense phase pump has two housings that are attached together using a single releasable fastener. The fastener can be released to allow the two housings to be separated thereby providing access to replaceable components. The replaceable components may include one or more pinch valves or one or more barrier elements. A pinch valve for a dense phase pump has a shape or profile for aligning the pinch valve when the pinch valve is installed in a pinch valve body. The pinch valve optionally has two end flanges, with each end flange having a shaped periphery. The two end flanges may have the same size and shape so that the pinch valve can be installed in either of two orientations that are inverse. A dense phase pump has a pump chamber that can be purged by purge gas that enters the pump off-axis from a purge path axis.

Abstract: Apparatus for detecting powder flow along a powder flow path includes a light source and a light detector for detecting light from the light source directed across the powder flow path as powder flows through said powder flow path. A circuit receives the output from the light detector and determines an average or RMS of the signal received by the light detector. The circuit may determine whether there is flow or no flow of powder or whether there is a change in flow rate of powder. Preferably, the apparatus is used in combination with a dense phase powder pump, which causes the powder to flow in pulses from the pump outlet into the powder flow path. More preferably, the light source and detector are enclosed in a housing that is connected between the pump outlet and a powder feed hose which supplies powder to a spray gun or hopper.

Abstract: A color changer has a common feed passage that is connected to two or more inlet passages. The common feed passage can be reverse purged in a direction that is opposite a direction of powder flow through the common feed passage. A valve element seals a supply port that connects the inlet passage to the common feed passage to eliminate dead space and form a near bore line seal. The valve element is an elastic material that expands in response to applied compressed air inside the valve element.

Abstract: A dense phase powder coating system includes a powder supply, dense phase pump, a spray gun and a diverter valve that can be used to select between conveying powder to the spray gun or circulating the powder back to the powder supply. The diverter valve may include two pneumatically actuate valve members. In one embodiment, the powder spray gun applies powder coating material to inside surfaces of a tubular container. A spray nozzle concept also is presented having a nozzle body with a conical deflector. The spray nozzle provides an uninterrupted flow between spray nozzle outlet holes and a deflector surface. The deflector may be integrally machined with the nozzle body to provide a one piece spray nozzle.

Abstract: A selectively configurable spray gun may include a gun body comprising a selectable forward section and a rearward section. The rearward section may be connected with either of two or more selectable forward sections so as to selectively configure the spray gun to operate either with a dense phase powder supply configuration or a with dilute phase powder supply configuration. The rearward section may include a selectable powder flow path that is connectable at an inlet end to a source of dense phase powder and at an outlet end to a selectable spray nozzle in the selectable forward section that may optionally include a diffuser. An adapter may be used to connect the rearward section with a selectable spray nozzle or air cap. A manual spray gun embodiment is also presented. A selectively configurable spray gun for use with a dense phase powder supply may include a smaller diameter powder tube that extends through a larger diameter powder tube.

Abstract: A color changer has a common feed passage that is connected to two or more inlet passages. The common feed passage can be reverse purged in a direction that is opposite a direction of powder flow through the common feed passage. A valve element seals a supply port that connects the inlet passage to the common feed passage to eliminate dead space and form a near bore line seal. The valve element is an elastic material that expands in response to applied compressed air inside the valve element.

Abstract: A dense phase powder coating system includes a powder supply, dense phase pump, a spray gun and a diverter valve that can be used to select between conveying powder to the spray gun or circulating the powder back to the powder supply. The diverter valve may include two pneumatically actuate valve members. In one embodiment, the powder spray gun applies powder coating material to inside surfaces of a tubular container. A spray nozzle concept also is presented having a nozzle body with a conical deflector. The spray nozzle provides an uninterrupted flow between spray nozzle outlet holes and a deflector surface. The deflector may be integrally machined with the nozzle body to provide a one piece spray nozzle.

Abstract: A powder spray gun includes a powder flow path inlet and a powder flow path outlet, the powder flow path inlet being connectable in a first configuration to a dilute phase powder pump and in a second configuration to a dense phase powder pump, wherein the powder spray gun comprises a spray nozzle that is the same for the first and second configurations. The powder flow path is provided by a powder tube that extends through the gun, with the powder tube having a first diameter at an inlet portion of the spray gun and a second diameter at an outlet portion of the spray gun, with the second diameter being greater than the first diameter. The powder flow path may also include a conical transition portion, and a member for adding air to the powder flow.

Abstract: A nozzle assembly for a material application device includes an expansion chamber for slowing down the velocity of powder fed to the nozzle from a dense phase pump. The nozzle assembly includes a nozzle insert that forms the expansion chamber and provides air assist function. The nozzle includes an integral deflector, and further includes a passageway for a charging electrode so that the electrical path is routed away from the powder path, while permitting the electrode tip to be centered in the powder spray pattern from the nozzle. The nozzle also includes air wash for the electrode. The nozzle outlet orifice has a cross-sectional area that is equal to or greater than the inlet cross-sectional area so that a slow moving dense phase powder cloud is produced by the nozzle.

Abstract: Apparatus and method for electrostatic charging of a container for an electrostatic coating operation includes a support member for supporting a container during an electrostatic coating operation with the support member comprising a non-metallic conductive material or electrically semiconductive portion that directly contacts a surface of the container. The electrically semiconductive portion comprises non-metallic, resistive or low conductivity material and is coupled to a source of electrical energy such that the container is electrostatically charged to an opposite polarity to offset or reduce electrostatic charge build up produced by the electrostatic coating operation.