API gate valves are industrial valves manufactured in accordance with the standards of the American Petroleum Institute (API). They are designed for high-pressure and harsh working conditions such as oil, natural gas and chemical industries. Their core features and technical points are as follows:
1. Definition and Standard Specifications
Core Definition
API gate valves are cut-off valves that realize the opening and closing control of pipeline media through the vertical movement of the gate to meet the sealing requirements of high-pressure pipeline systems in the fields of oil, chemical industry, and power.
Implementation Standards
The design and manufacturing follow the standards of API 600 (steel bolted bonnet gate valve), API 6D (pipeline valve specification) and ISO 10434, and the inspection standard is API 598.
2. Structural Design Features
Valve Body and Material
The valve body adopts casting/forging technology, and the materials include carbon steel (WCB), stainless steel (CF8/CF8M) and alloy steel (WC6/WC9), and the pressure resistance level covers Class 150~2500 (up to PN420).
Large-diameter models (DN15~1500) are often equipped with an extended valve body to adapt to the needs of long-distance pipelines.
Sealing technology Bidirectional elastic gate: It can automatically compensate for valve body deformation to avoid leakage caused by temperature or pressure fluctuations.
Double sealing structure: Some models integrate metal hard seals and fire-resistant graphite packing to meet API 607 fire protection requirements.
3. Performance parameters
| Performance Dimension | Technical indicators |
|---|---|
| Pressure bearing capacity | Class 150~2500 (up to PN420), test pressure according to API 598 |
| Temperature range | -196℃ (cryogenic conditions) to +560℃ (high temperature steam) |
| Sealing level | Leakage rate meets ANSI B16.104 Class VI (zero leakage) |
| Drive mode | Supports handwheel, gearbox, electric actuator or pneumatic device |
4. Core advantages
Low flow resistance design: The full-bore structure reduces the pressure drop of the medium and is suitable for long-distance pipelines.
Anti-particle wear: Carbide sealing surfaces (such as tungsten carbide) can withstand the erosion of solid particle-containing media.
Emergency protection function: Some models are equipped with an emergency grease injection interface, which can quickly inject sealing grease for temporary plugging in case of sudden leakage.
5. Typical application scenarios
Oil and gas transportation: high-pressure natural gas pipelines (Class 600 and above), LNG tank inlets and outlets.
Chemical plant: high-temperature reactor medium cut-off, corrosive liquid control.
Power system: power station boiler water supply pipeline, steam drain system.
Selection suggestions
The material and sealing form should be comprehensively selected based on the medium characteristics (corrosiveness, particle content), temperature and pressure curve and fire protection requirements. The alloy steel + metal seal configuration is preferred for high temperature and high pressure scenarios
