Excess flow valves in propane systems are designed with a bypass not to exceed what size opening?

Excess flow valves in propane systems serve a critical safety function by automatically shutting off or restricting flow in the event of a sudden drop in pressure, which typically occurs during a leak or a catastrophic failure in the system. The design of these valves includes a bypass feature that is calibrated to allow a designated amount of gas to flow while still providing protection against excessive flow.

The size of this bypass opening is crucial for ensuring that the valve can effectively monitor and respond to flow conditions without becoming overly restrictive during normal operation. The bypass size, which is specified to not exceed a particular drill size, plays a key role in maintaining operational efficiency while still safeguarding the system.

In this context, a #60 drill size opening is established as the maximum size for the bypass in excess flow valves. This size strikes a balance between allowing enough gas flow for efficient system operation and providing an effective safety mechanism to prevent excessive flows in emergency situations. Understanding this specification is important for anyone involved in propane gas installations and safety assessments to ensure compliance with safety regulations and optimal system performance.