Screwed safety relief valves" refers to safety relief valves that are designed with threaded connections, often referred to as screwed connections. These valves are typically installed in systems where a threaded connection is suitable for securing the valve to the pressure vessel or piping. It's important to note that while screwed safety relief valves offer advantages in terms of ease of installation and compact design, their use is often limited to lower-pressure applications. In higher-pressure and critical applications, flanged or welded connections may be more common. As with any safety relief valve, proper sizing, installation, and adherence to industry standards are crucial for their effective and safe operation.