Many domestic manufacturers produce gate valves, and connection dimensions are largely inconsistent. They are mainly divided into the following categories: 1. Machinery Ministry standard valves manufactured according to JB/T2203-1999 "Gate Valve Structural Length"; 2. National standard valves manufactured according to GB/T12221-2005 "Metal Valves Structural Length"; 3. American standard valves manufactured according to ASME B16.10-2009 "Valves Face-to-Face and End-to-End Dimensions".
Gate valves are classified into two types based on the structure of their gate: wedge gate and parallel gate. Wedge gate valves have three structures: single gate, double gate, and resilient gate.
Gate valves are further classified into flat gate valves and knife gate valves based on their structural type.
The working principle of a manual gate valve: Turning the handwheel, through the threaded movement between the handwheel and the valve stem, raises or lowers the valve plate connected to the valve stem, achieving the opening and closing action.
Based on the body/shell material, gate valves can be classified as:
- Metal valves: such as carbon steel valves, alloy steel valves, stainless steel valves, cast iron valves, titanium alloy valves, Monel valves, copper alloy valves, lead alloy valves, etc.
- Metal-lined valves: such as rubber-lined valves, fluoropolymer-lined valves, lead-lined valves, plastic-lined valves, enamel-lined valves.
- Non-metal valves: such as ceramic valves, glass valves, and plastic valves.
