In industrial pipelines, ball valves and globe valves are two indispensable core control components. Their working principles and application scenarios are vastly different, directly affecting the efficiency of fluid transportation and the overall safety of the system. 

Ball valve: Streamlined design with rotary opening and closing mechanism 

The core advantage of the ball valve lies in its straight-through flow channel design. It achieves on-off control by rotating the ball around its axis by 90° through the movement of the valve stem. 

Advantages: The opening and closing process is fast, taking only 0.5 to 2 seconds to complete a 90° rotation. The flow resistance coefficient is also relatively low, ranging from 0.05 to 0.1 (equivalent to the same pipe length). 

- Feature: The hard-sealed ball valve adopts a metal-to-metal sealing structure, ensuring sealing reliability even in 300℃ high-temperature heavy oil pipelines. In contrast, the soft-sealed ball valve (such as the polytetrafluoroethylene valve seat) is suitable for clean media with zero leakage requirements in the pharmaceutical industry. 

Application: It is particularly suitable for media containing particles, high viscosity, and corrosive substances. It is used for emergency shut-off in long-distance oil pipelines, applied in multi-phase flows in chemical industries, and for precise sampling in laboratories. 

Case Study: In the catalytic cracking unit of an oil refinery, by replacing the traditional gate valve with a hard-sealed V-type ball valve, the system pressure drop decreased from 0.8 MPa to 0.2 MPa, resulting in annual energy savings of 1.2 million yuan. The shearing effect of the ball valve increased the throughput rate of catalyst particles by 40%, and the wear cycle of the valve seat was extended from 3 months to 18 months. 

Stop valve: A vertical movement-based forced sealing mechanism 

The stop valve achieves opening and closing by the valve stem pushing the valve disc to move vertically along the center line of the valve seat. Its forced sealing feature requires continuous pressure to be applied during the closing process. 

Advantages: The opening and closing speed is slow. The valve disc needs to move up and down by 10-30mm, taking 5-15 seconds. The sealing level is high, capable of reaching ANSI Class IV-V (minor leakage). 

Features: In the high-temperature steam pipelines of thermal power plants, the forged steel stop valve, with its hard alloy clad sealing surface of the valve disc and valve seat, can withstand a pressure of 4.0 MPa and a temperature of 540℃. The angle type stop valve effectively reduces the crystalline deposition of the medium by changing the flow direction in the silica removal workshop of alumina production. The valve body is designed for disassembly, facilitating regular cleaning. 

Application: It is suitable for cleaning media and situations requiring flow regulation. It can be applied in steam regulation in thermal power plants, as well as for precise sampling in laboratories. 

Case Study: A biopharmaceutical factory selected 316L stainless steel soft-sealing stop valves for its cleanroom. During the SIP (in-line steam sterilization) verification process, the temperature uniformity inside the valve body reached ±2℃, meeting the requirements of FDA certification. Compared to the ball valve solution, the system's microbial contamination rate decreased by 92%.