| 摘要 |
A ball valve assembly and method of construction. The valve includes a one-piece ball and shaft in a valve housing formed of a body portion and an end portion, the body portion being cast. The body portion has a flow port at a first end thereof and a large opening at a second end thereof, and an elongated passageway is formed in the body portion for receipt of the shaft. A relatively thick wall portion is disposed toward the body first end and a relatively thin wall portion toward the body second end around the passageway. The passageway can be smooth bore or threaded throughout its length. A scallop may be formed in the relatively thin wall portion extending substantially perpendicular to the direction of elongation of the passageway, the scallop being machined or being formed during casting. The shaft is inserted through the body portion large opening and through the scallop to and through the passageway, and then the ball is moved so that it is in sealing relationship with sealing means associated with the body portion. The end portion is connected to the body portion, and a bushing is affixed in operative association with the passageway threads or bore for supporting and sealing the shaft. The interfaces between the body portion and the end portion, and between the bushing and the body portion may be welded where a poisonous fluid or the like is to be valved by the assembly. |
