| 摘要 |
PURPOSE:To plate only the necessary part of a valve body and also to reduce the cost of plating treatment by covering a connecting part and both sides of a through- hole of the valve body and immersing it in plating liquid and communicating both the space of the inside of a cover and the through-hole to outside air. CONSTITUTION:Covers 8A, 8B are respectively fitted to the up-and-down connecting parts 4A, 4B of a valve body 3 for a ball valve, and caps 9A, 9B are respectively fitted to both sides of a through-hole 5. The valve body 3 is positioned so that the upper aperture part of the upper cover 8B is communicated to the outside air side and thereafter immersed in a plating treatment vessel 15. Further a ventilating pipeline 17 wherein the inside space of the through-hole 5 and outside air are communicated thereby is fitted to one hand of the cap body 9B. Even when the temp. of plating liquid 7 rises in a time of plating treatment, the air incorporated in the through-hole 5 is exhausted through the ventilating pipeline 17 and the inside of the through-hole 5 is not made to a high-pressure state. The up-and-down covers 8A, 8B are communicated via a hollow part, the space of the inside of the upper cover 8A is communicated to outside air, and therefore is not made to the high-pressure state. As a result, only the spherical surface part of the valve body 3 is brought into contact with plating liquid 7 in a good state and subjected to plating treatment.
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