Introduction to the distinction between open-stem gate valves and dark-stem gate valves
Release time:
2024-10-22 16:19
伟拓 伟拓流体设备 WATO Wuhan Weituo Fluid Control Equipment Co., Ltd
Gate valve (gate valve) is an opening and closing parts of the gate, the direction of movement of the gate and the direction of the fluid perpendicular to the gate valve can only be fully open and fully closed, can not be adjusted and throttling. The gate valve is sealed by the contact between the valve seat and the gate. Usually, the sealing surface is surfacing with metal materials to increase wear resistance, such as surfacing 1Cr13, STL6, stainless steel, etc.
Domestic production of gate valve manufacturers more, the connection size is mostly not uniform. Mainly divided into the following categories:
1, according to JB/T2203-1999 "gate valve structure length" production of the mechanical department standard valve;
2, according to GB/T12221-2005 "metal valve structure length" production of national standard valve.
3. American standard valves produced according to ASME B16.10-2009 "face-to-face and end-to-end dimensions of valves.
Gate valve according to the structure of the stem can be divided:
1 stem gate valve: the stem nut on the bonnet or bracket, when opening and closing the gate, use the rotating stem nut to realize the lifting of the stem. This structure is beneficial to the lubrication of the valve stem, and the degree of opening and closing is obvious, so it is widely used.
2 Dark rod gate valve: The stem nut is in the valve body and is in direct contact with the medium. When opening and closing the gate, it is realized by rotating the valve stem. The advantage of this structure is that the height of the gate valve always remains unchanged, so the installation space is small, suitable for large diameter or limited installation space of the gate valve. This structure is equipped with an opening and closing indicator to indicate the degree of opening and closing. The disadvantage of this structure is that the valve stem thread not only cannot be lubricated, but also directly accepts the erosion of the medium and is easily damaged.
The main difference between bright stem gate valve and dark stem gate valve:
1. The lifting screw of the dark rod flange gate valve only rotates without moving up and down. Only a rod is exposed. The nut is fixed on the gate. The gate is lifted by the rotation of the screw without visible gantry. The lifting screw of the open rod flange gate valve is exposed. The nut is tightly attached to the handwheel and is fixed (does not rotate or move axially). The gate is lifted by rotating the screw, the screw and the gate only have relative rotational movement without relative axial displacement, and the appearance is a gate-shaped bracket.
The dark rod valve cannot see the lead screw, while the bright rod can see the lead screw.
3. When the valve is switched on and off, the steering wheel and the valve stem are connected together and relatively immobile. It is opened and closed by the valve stem rotating at a fixed point to drive the valve clack up and down. The open stem valve raises or lower the disc through the threaded drive between the stem and the steering wheel.
To put it simply, the open stem 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.
2022-12-19
Wuhan Weituo Fluid Control Equipment Co., Ltd
Address: 1706, Building D, Wuhan Living Room, No.8 Hongtu Avenue, Dongxihu District, Wuhan City
Telephone:0086-18942929031 0086-18571829295
Landline:0086-027-83612831
Fax: 0086-027-83612830
E-mail:watosong@watovalve.com
Website:www.watovalve.com
