阀门密封结构图

结构说明和工作原理 About the structure and working principle

(一)浮动式球阀 Floating ball valve

1、阀门开、关位置指示Indication of valve's open and close positions：       

球、阀杆、手柄是一个装配单元，阀杆头部采用扁方结构，由手柄所处位置容易辨别出阀门是处于开位置或关位置。当手柄或阀杆头部的扁方与管线平行时，阀门处于全开位置；当手柄或阀杆头部的扁方与管线垂直时，阀门处于全关位置。

Ball, stem and handle are one assembly unit. The stem head is a flat-square structure and the valve is easy to be seen either in the opened or closed position from the place the handle is in. When the handle or the flat-square of the stem head is parallel with the pipeline, the valve is in the fully opened position; while in the fully closed one when vertical to the pipeline.

2、锁定装置Locker：       

为防止误操作阀门，在阀门的全开和全关位置可用挂锁锁定阀门，特别是安装在野外的阀门或当工艺流程中不允许开或关阀门时，为防止其他人员错误操作阀门，将阀门位置锁定是很重要的。

To prevent maloperation of the valve, a hanging lock can be used to lock it when in the fully opened or closed position, which is very important especially for the valve mounted outside or not allowed to be opened or closed by the technological flow.

3、阀杆防飞结构Stem fly-resisting structure：       

当介质通过阀门时，阀体中腔的压力可能将阀杆推出。为防止这种情况发生，在阀杆下部设置一防飞出结构(图1)。这样，即使火灾时，填料、止推轴承被烧损或其它原因引起填料等损坏，阀体内的介质压力将使阀杆台肩与阀体上密封面紧密接触，防止介质大量从损坏的填料部位处泄漏。

The stem may be pushed out by the pressure in the middle cavity of the body when the medium goes through the valve. To prevent this, a fly-resisting structure is made on the lower part of the stem (Fig. 1). In this way, even if the packing and/or thrust bearing are burnt out in a fire or damaged by other causes, the medium's pressure inside of the body will have both stem flange and upper sealing face of body tightly contacted so as to prevent a lot of medium from leaking from the damaged packing place.

4、防静电装置及防火结构Electrostatic-proof device and fire-fighting structure：       

设计了防静电装置(图2)和防火结构(图3)。当发生火灾时，一旦阀座被烧损，球体将直接和阀体上的金属面接触，从而阻止介质大量从烧损的阀座处泄漏。

Both electrostatic-proof device (Fig. 2) and fire-fighting structure (Fig. 3) are designed. Once the seat ring is burnt out in case of a fire, the ball would be directly contacted with the metal face of the body so as to prevent a lot of medium from leaking from the burnt place of the seat ring.

6、全通径或缩径Full or reduced diameter：       

阀门公称通径与管线内径一致(客户要求时可为缩径)，以便管线清扫(图6)。

The valve nominal diameter is identical to the inner diameter of the pipeline (which can be reduced one if so required by users) for the sake of cleaning (Fig. 6).