Molten metal pouring pipe for pressure-casting machine

In a pressure-casting machine that contains a molten metal delivery system, which comprises:

• a mold;
• a closed vessel arranged below said mold;
• a molten metal pouring pipe made of a refractory, said molten metal pouring pipe having a center axis, a length of at least 4 m, and an outside diameter of at least 350 mm;
• an upper end of said molten metal pouring pipe being attached substantially vertically from below to an opening in a bottom wall of said mold of the pressure-casting machine;
• a lower end of said molten metal pouring pipe extending through a lid of said closed vessel arranged below said mold, and said lower end being immersed into molten metal received in a ladle arranged in said closed vessel;
• and
• said molten metal pouring pipe comprising at least two pipe sections connected to each other in series and in a liquid-tight manner;
• the improvement wherein:
• said at least two pipe sections have mutually engageable screw threaded sections for connecting said pipe sections to each other by means of a threaded joint formed by engagement of screw threads of said mutually engageable screw threaded sections, said screw threaded sections each having tapered surfaces provided with said screw threads, said tapered surfaces each having an inclination angle within a range of from 2.0.degree. to 15.0.degree. relative to the center axis of said molten metal pouring pipe, whereby molten metal is moved upwardly through said pouring pipe, under pressure, with liquid tightness.