Rising Stem Gate Valves
The rising stem is fixed to the gate and they rise and fall together when the valve is operated, providing a visual indication of the valve position and the ability to lubricate the stem. The nut rotates around the threaded rod and moves it. This type of valve has a threaded stem inside, and the packing wears out due to the up and down and rotational movement of the stem. This type is only suitable for installation on the ground.
Non-rising stem gate valve
The non-rising stem enters the gate through the threads and rotates as the wedge is raised and lowered inside the valve. The rotation of the wheel operates the valve, but the stem does not come out of the housing. They occupy less vertical space because the stem stays inside the valve body. Non-rising valves are almost always equipped with an indication of the valve position. Gate valves with non-rising stems are suitable for above-ground and underground installations.