FIELD: technological processes.
SUBSTANCE: return valve is equipped with sealant arranged in the form of ring. Ring may be displaced between open position of channel for melt and closed position of channel for melt. On front surface of ring groove is provided that forms ring bulge. Bulge is made with the possibility of bending under the effect of injected material for provision of seal between specified ring portion and wall of melt channel. Groove may be of V-shape form.
EFFECT: increase durability of return valve sealant operation and efficiency of its sealing.
13 cl, 9 dwg
