| 摘要 |
The invention relates to a valve that contains a piston (2) linked with the valve body (8) and received in a housing (4), and a stuffing box (14) interposed between the piston (2) and the housing (4). The stuffing boxes of valves used for media having a high melting point and being operated close to the melting point risk being damaged by so-called freezing medium due to the adhesive properties of the medium in temperature ranges below the melting point. The aim of the invention is therefore to improve such a valve with few constructive efforts in such a manner that the material of the stuffing box reliably works in the liquid range of the medium. To this end, the housing (4) is provided with a heating device (16) in the area of the stuffing box (14). The axial length of said heating device is larger than the axial length of the stuffing box (14), and the heating device (16) axially protrudes beyond an axial end (22) of the stuffing box (14) by a predetermined length (24, 28). |
