Abstract: A composite concrete pipe in which both the inner and outer surfaces are plastic. The pipe may be formed of any diameter by forming the inner and outer plastic surfaces from helically wrapped interlocking plastic strips to form the diameters desired.

Abstract: A pressure control and regulating device for the proper filling of pneumatic tires and the like which device includes a filling stem receiving end for removeably attaching the same to a tire during filling and a pressure line receiving end to which the source of air pressure is attached with a pressure release, spring calibrated mechanism arranged between such ends which spring will open the unit for release of pressure to atmosphere upon the pressure reaching a predetermined level, the release directing the air from the unit past a whistle producing passage for the production of a constant pitch sound.