Shutoff valves must be designed to withstand what in relation to the system's working pressure?

Shutoff valves play a crucial role in the safety and functionality of a compressed natural gas system. The design requirement that these valves must withstand four times the system's working pressure ensures that they can operate safely under maximum stress conditions. This level of durability is essential to prevent failures that could lead to leaks, explosions, or other hazardous situations.

By requiring shutoff valves to withstand four times the working pressure, the industry addresses potential pressure surges or fluctuations that may occur during operation. This is especially important for CNG systems, where high pressure is inherent to their design and function. Such a robust design provides an added safety margin, ensuring that the valves will not fail even under extreme circumstances, thus protecting both equipment and personnel.

In contrast, lower multiples such as one and a half, two, or five times may not provide sufficient assurance of safety and reliability. While they are also important considerations in design, they do not meet the established safety standards that are critical for the high-pressure environment of a compressed natural gas system. Therefore, the requirement for shutoff valves to withstand four times the working pressure is a crucial standard in ensuring the integrity and safety of the entire system.