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、暗桿閘閥看不見絲杠，而明桿的能看見絲桿。

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

3、暗桿閘閥在開關時方向盤與閥桿是連接在一起相對不動的，它是通過閥桿在固定點轉動來帶動閥瓣向上提升和下閘來完成啟閉的。明桿閘閥則是通過閥桿與方向盤的螺紋傳動來提升或者降下閥瓣。說簡單點就是明桿閘閥是閥瓣連著閥桿一起做上下運動，方向盤始終在固定點。

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.

閘閥按閥桿的構造可分為：

Gate valves can be divided into:

1、明桿閘閥：明桿閘閥：閥桿螺母在閥蓋或支架上，開閉閘板時，用旋轉閥桿螺母來實現閥桿的升降。這種結構對閥桿的潤滑有利，開閉程度明顯，因此被廣泛采用。通常在升降桿上有梯形螺紋，通過閥門頂端的螺母以及閥體上的導槽，將旋轉運動變為直線運動,也就是將操作轉矩變為操作推力。明桿閘閥的啟閉件是閘板，閘板的運動方向與流體方向相垂直，明桿閘閥只能作全開和全關,不能作調節和節流。

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、暗桿閘閥：暗桿閘閥又叫旋轉桿閘閥(亦叫暗桿楔式閘閥)。閥桿螺母在閥體內，與介質直接接觸。開閉閘板時，用旋轉閥桿來實現。暗桿閘閥的啟閉件是閘板，閘板的運動方向與流體方向相垂直，閘閥只能作全開和全關,不能作調節和節流。閥桿螺母設在閘板上，手輪轉動帶動閥桿轉動,而使閘板提升，通常在閥桿的底端有梯形螺紋，通過閥門底端的螺紋以及閥瓣上的導槽，將旋轉運動變為直線運動，也就是將操作轉矩變為操作推力。

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.