Analysis Of 3-way Ball Valve Sealing Form And Technical Requirements

The following information provides a comprehensive analysis of 3 Way Ball Valve sealing types and technical requirements:
The main sealing structure of stainless steel ball valves, the choice of sealing materials, and other factors influence the sealing performance, performance, and reliability of ball valves. Currently, stainless steel ball valves primarily utilize a combined sealing seat structure consisting of an elastic expansion ring and a polytetrafluoroethylene lip seal. Stainless steel ball valves are widely used for quick shutoff, flow direction change, and automatic control in various piping systems. They can be actuated manually, electrically, or pneumatically.
The sealing structure of a stainless steel ball valve consists of three main components: the first is the seal between the main and auxiliary valve bodies, achieved by a seal adjustment gasket; the second is the seal between the main valve body and the valve stem, achieved by standard "V"-shaped packing or O-rings, forming the ball valve's external seal. The third is the seal between the ball and the main and auxiliary valve bodies, achieved by the sealing seat, forming the ball valve's main seal. The sealing performance of the main seal structure affects the performance of the ball valve and is a critical sealing structure in ball valve design and manufacturing.
The following points focus on the non-metallic seal (also known as soft seal) structure of the ball valve's main seal. 1. Ball Valve Sealing Requirements: National standards stipulate that the sealing performance of non-metallic sealed ball valves must meet Class A requirements of GB/T13927 "General Valve Pressure Test."
2. The main factors affecting the sealing performance of stainless steel ball valves are the roughness of the sealing surface and the roundness of the ball.
3. The main sealing structure of the ball valve utilizes a combined seal seat consisting of an elastic expansion ring and a polytetrafluoroethylene lip seal seat. This utilizes the excellent elastic-plastic deformation capacity of the metal elastic expansion ring to enhance its overall elastic-plastic deformation and compensation capabilities, improving the sealing performance of the ball valve. The use of a sealing seat with an elastic element eliminates the need for seal adjustment gaskets, enabling the elastic element to achieve and adjust the pre-compression. The sealing seat with an elastic element not only achieves the necessary pre-compression but also compensates for the pre-load pressure within the elastic deformation range of the elastic element, resulting in a relatively long service life for stainless steel ball valves.