u packing seal

https://www.apimeivalve.com/product-valve-stem-u-packing-seals.html

U-packing seals are a type of sealing solution that is commonly used in hydraulic and pneumatic systems to prevent leakage of fluids or gases. These seals are typically made from rubber or other elastomeric materials and are designed to fit into a groove or recess in the housing of the system is sealed.

The u-packing seals consist of a packing made of rubber combined with a housing made of Teflon vulcanized. The rubber is the main pressure-bearing element, and the interference of the inner and outer diameters ensures that the housing is tight against the sealing contact surface, thus realizing the sealing principle.

The U-shaped cross-section of the seal gives it its name, as it resembles the letter "U". The seal is typically installed with the open end of the U facing the pressure being sealed, which allows the pressure to force the lips of the U against the surface being sealed, creating a tight seal.

U-packing seals are known for their ability to handle high pressures and provide reliable sealing performance over a wide range of temperatures and operating conditions. They are commonly used in medium-pressure valves with good leakproof performance. As a low-cost valve stem seal is widely used in the petrochemical industry.