A dense phase powder pump for particulate material, comprising: a first housing , a gas permeable filter disposed in said first housing characterized by : a pinch valve housing adapted to receive four pinch valves , a body comprising four pressure chambers , wherein the pinch valve housing is transparent and wherein said pinch valve housing is removable as a unit from the pump , four pinch valves installed in said pressure chambers , each pinch valve , comprising: a body having a central particulate material flow passage therethrough and a pair of diametrically opposed and longitudinally extending ribs along opposite sides of the valve body , a first end flange on a first end of said body and a second end flange on an opposite end of said body , wherein each said first end flange and second end flange have a larger outside diameter than said body , at least one end flange of said first end flange and said second end flange having a shaped periphery for aligning the pinch valve when the pinch valve is installed in said pressure chamber , wherein said at least one end flange has a circular periphery with at least one non-circular portion. a first housing , a gas permeable filter disposed in said first housing characterized by : a pinch valve housing adapted to receive four pinch valves , a body comprising four pressure chambers , wherein the pinch valve housing is transparent and wherein said pinch valve housing is removable as a unit from the pump , four pinch valves installed in said pressure chambers , a pinch valve housing adapted to receive four pinch valves , a body comprising four pressure chambers , wherein the pinch valve housing is transparent and wherein said pinch valve housing is removable as a unit from the pump , four pinch valves installed in said pressure chambers , each pinch valve , comprising: a body having a central particulate material flow passage therethrough and a pair of diametrically opposed and longitudinally extending ribs along opposite sides of the valve body , a first end flange on a first end of said body and a second end flange on an opposite end of said body , wherein each said first end flange and second end flange have a larger outside diameter than said body , at least one end flange of said first end flange and said second end flange having a shaped periphery for aligning the pinch valve when the pinch valve is installed in said pressure chamber , wherein said at least one end flange has a circular periphery with at least one non-circular portion. a body having a central particulate material flow passage therethrough and a pair of diametrically opposed and longitudinally extending ribs along opposite sides of the valve body , a first end flange on a first end of said body and a second end flange on an opposite end of said body , wherein each said first end flange and second end flange have a larger outside diameter than said body , at least one end flange of said first end flange and said second end flange having a shaped periphery for aligning the pinch valve when the pinch valve is installed in said pressure chamber , wherein said at least one end flange has a circular periphery with at least one non-circular portion. <EOS>