NPT, short for National Pipe Taper, is a type of tapered pipe thread used in American national standards, commonly found in pipe connections. In ball valves, NPT threads are typically used to connect fittings with the same thread. This thread features a large angle and a small taper, making it a thread type with excellent sealing performance.
NPT ball valves are ball valves designed with NPT (American National Pipe Taper) interfaces and are widely used in industries such as petroleum, chemical, natural gas, water treatment, and pharmaceuticals for controlling fluid flow or regulating flow. Their core feature lies in the combination of interface standards and structural design, meeting the sealing and operational reliability requirements under various operating conditions.
Core Design Features
NPT Thread Interface
Utilizes American standard tapered pipe threads (NPT) with a thread angle of 60°. Sealing is achieved through a tapered fit, suitable for medium and low-pressure piping systems.
Interface sizes range from 1/8" to 4", allowing direct connection to standard NPT fittings, instruments, and other equipment, reducing adaptation costs.
Spherical Structure
Floating ball or fixed ball design. The floating ball structure achieves sealing through media pressure, while the fixed ball structure reduces operating torque through bearing support.
The ball surface undergoes a hardening treatment (e.g., chrome plating, tungsten carbide coating) to improve wear resistance and corrosion resistance.
Sealing Materials
Soft Seal: Utilizes polytetrafluoroethylene (PTFE), reinforced PTFE, or fluororubber (FKM), suitable for non-particulate media, achieving a sealing class of VI (zero leakage).
Hard Seal: Metal-to-metal seal (e.g., stainless steel to stainless steel), suitable for high-temperature, high-pressure, or particulate media, achieving a sealing class of IV.
Operation Method
Manual: Equipped with a handle, worm gear, or lever operating mechanism, suitable for small-diameter valves.
Electric/Pneumatic: Integrated actuator for remote automated control, suitable for large-diameter or high-frequency operation scenarios.
Performance Parameters
Pressure Range:
Soft Seal: 150LB~600LB (PN16~PN100), maximum pressure resistance 10MPa.
Hard seal: 900LB~2500LB (PN150~PN420), maximum pressure resistance 42MPa.
Temperature range:
Soft seal: -29℃~180℃ (PTFE seal), -10℃~230℃ (fluororubber seal).
Hard seal: -46℃~550℃ (stainless steel).
Applicable media:
Liquids: Water, oil, acid and alkali solutions, organic solvents.
Gas: Air, nitrogen, natural gas, steam.
Special media: Fluids containing particles (requires hard seal structure).
