1. The lifting screw of the non rising stem gate valve only rotates without any upward or downward movement, and only one rod is exposed. Its nut is fixed on the gate plate, and the gate plate is lifted by the rotation of the screw, without a visible gate frame; The lifting screw of the rising stem gate valve is exposed, and the nut is tightly attached to the handwheel and fixed (not rotating or axially moving). The gate is lifted by rotating the screw. The screw and gate only have relative rotational motion without relative axial displacement, and the appearance is a door-shaped bracket.

2、暗杆闸阀看不见丝杠，而明杆的能看见丝杆。

2. The blind stem gate valve cannot see the screw, while the open stem can see the screw.

3、暗杆闸阀在开关时方向盘与阀杆是连接在一起相对不动的，它是通过阀杆在固定点转动来带动阀瓣向上提升和下闸来完成启闭的。明杆闸阀则是通过阀杆与方向盘的螺纹传动来提升或者降下阀瓣。说简单点就是明杆闸阀是阀瓣连着阀杆一起做上下运动，方向盘始终在固定点。

3. When a non rising stem gate valve is opened or closed, the steering wheel and valve stem are connected together and relatively stationary. It is achieved by rotating the valve stem at a fixed point to drive the valve disc up and down to complete the opening and closing. Rising stem gate valves raise or lower the valve disc through a threaded transmission between the valve stem and steering wheel. Simply put, a rising stem gate valve is a valve disc that moves up and down together with the valve stem, and the steering wheel is always at a fixed point.

闸阀按阀杆的构造可分为：

Gate valves can be divided into:

1、明杆闸阀：明杆闸阀：阀杆螺母在阀盖或支架上，开闭闸板时，用旋转阀杆螺母来实现阀杆的升降。这种结构对阀杆的润滑有利，开闭程度明显，因此被广泛采用。通常在升降杆上有梯形螺纹，通过阀门顶端的螺母以及阀体上的导槽，将旋转运动变为直线运动,也就是将操作转矩变为操作推力。明杆闸阀的启闭件是闸板，闸板的运动方向与流体方向相垂直，明杆闸阀只能作全开和全关,不能作调节和节流。

1. Rising stem gate valve: Rising stem gate valve: The valve stem nut is placed on the valve cover or bracket. When opening and closing the gate, the valve stem nut is rotated to achieve the lifting and lowering of the valve stem. This structure is beneficial for the lubrication of the valve stem and has a significant degree of opening and closing, therefore it is widely adopted. Usually, there is a trapezoidal thread on the lifting rod, which transforms the rotating motion into linear motion through the nut at the top of the valve and the guide groove on the valve body, that is, the operating torque is converted into the operating thrust. The opening and closing component of the rising stem gate valve is the gate, and the movement direction of the gate is perpendicular to the direction of the fluid. The rising stem gate valve can only be fully opened and fully closed, and cannot be adjusted or throttled.

2、暗杆闸阀：暗杆闸阀又叫旋转杆闸阀(亦叫暗杆楔式闸阀)。阀杆螺母在阀体内，与介质直接接触。开闭闸板时，用旋转阀杆来实现。暗杆闸阀的启闭件是闸板，闸板的运动方向与流体方向相垂直，闸阀只能作全开和全关,不能作调节和节流。阀杆螺母设在闸板上，手轮转动带动阀杆转动,而使闸板提升，通常在阀杆的底端有梯形螺纹，通过阀门底端的螺纹以及阀瓣上的导槽，将旋转运动变为直线运动，也就是将操作转矩变为操作推力。

2. Non rising stem gate valve: Non rising stem gate valve, also known as rotary stem gate valve (also known as non rising stem wedge gate valve). The valve stem nut is in direct contact with the medium inside the valve body. When opening and closing the gate, it is achieved by rotating the valve stem. The opening and closing component of the non rising stem gate valve is the gate, and the movement direction of the gate is perpendicular to the direction of the fluid. The gate valve can only be fully opened and fully closed, and cannot be adjusted or throttled. The valve stem nut is located on the gate plate, and the handwheel rotates to drive the valve stem to rotate, causing the gate plate to lift. Usually, there is a trapezoidal thread at the bottom of the valve stem. Through the thread at the bottom of the valve and the guide groove on the valve disc, the rotational motion is transformed into linear motion, that is, the operating torque is transformed into operating thrust.