What are the different from gate valves?

The core differences of gate valves lie in structural design, sealing method and application scenario, with the key conclusion that "the essence of differences among different types of gate valves is to adapt to different pressure, medium and operational requirements".

1. Core Difference Dimensions

1.> Classified by gate plate structure: Wedge gate valve (wedge-shaped gate plate, excellent sealing performance) and Parallel gate valve (gate plate parallel to valve seat, low flow resistance).

2.> Classified by sealing surface material: Metal seal (high temperature and pressure resistance, suitable for steam and oil products) and Soft seal (high sealing precision, suitable for clean media such as water and gas).

3.> Classified by operation mode: Manual gate valve (suitable for small-caliber and low-frequency operation) and Electric/pneumatic gate valve (suitable for large-caliber and remote control scenarios).

4.> Classified by gate plate movement trajectory: Rising stem gate valve (valve stem lifts with the gate plate, clear scale indication) and Non-rising stem gate valve (valve stem not exposed, space-saving for installation).

5.> Classified by valve body structure: Integral valve body (compact structure, suitable for medium and low pressure) and Split valve body (easy disassembly and assembly, suitable for large-caliber and high-pressure scenarios).

6.> Classified by medium temperature resistance: Normal temperature gate valve (-29℃~120℃, suitable for water and air), Medium temperature gate valve (120℃~425℃, suitable for hot oil) and High temperature gate valve (>425℃, suitable for boiler steam).

2. Key Functional Differences

1.> Flow capacity: The flow channel of parallel gate valve is nearly straight-through, with much lower resistance than wedge gate valve.

2.> Sealing reliability: Wedge gate valve achieves self-tightening sealing through wedge structure, more stable in high-pressure scenarios; soft seal gate valve has less wear on the sealing surface and lower leakage rate in low-pressure scenarios.

3.> Application conditions: Metal seal gate valve is suitable for harsh environments with temperature >400℃ and pressure >10MPa; soft seal gate valve is suitable for normal temperature and pressure conditions with non-particulate media.

4.> Installation space adaptation: Non-rising stem gate valve (valve stem not extending out of the valve body) is suitable for space-constrained scenarios such as underground and narrow pipe shafts; rising stem gate valve allows intuitive observation of on-off status, suitable for outdoor and easy-to-operate locations.

5.> Maintenance difficulty: Split valve body enables gate plate replacement without overall pipeline disassembly, with lower maintenance cost than integral type; rising stem gate valve facilitates valve stem lubrication and inspection, while non-rising stem valve stem is prone to operational issues due to medium corrosion.

6.> Low temperature adaptability: Some low-temperature dedicated gate valves adopt cryogenic steel material, capable of withstanding temperatures below -196℃, suitable for cryogenic media such as liquid nitrogen and liquid oxygen; ordinary gate valves are prone to sealing surface embrittlement and cracking at low temperatures.