A vacuum melting system for KNO3-Sorbitol Propellants. Two melting systems for KNO₃-sorbitol motors with reduced intervention during the melting process and with the possibility to apply vacuum in order to reduce the air bubbles, have been developed. The main objective is increased safety and reproducibility.

The two systems are for the P-100, a motor with a diameter of 9.6 cm and one for the smaller KNSB58, a 6.0 cm diameter motor. The first picture shows the different components of the larger system.

The systems consist mainly of two identical aluminum tubes A en B. A is coated at the inside and will eventually contain the propellant grain after melting. The lower tube A is pressed in the bottom plate D and kept in place by means of an O-ring. Part E hold both tubes A and B together with 2 O-rings. The cover plate F is provided with a tube G which allows to apply vacuum to the liquid propellant. The screws H (of which only 2 out of 6 are shown in the drawing) hold all parts together. I is the central rod. It is fixed to the bottom plate with the screw K which is fixed to part J.