Where should a readily accessible manual shut-off valve for a commercial appliance be installed?

The proper installation location for a readily accessible manual shut-off valve is in the valve train drop or riser. This point is ideal because it allows for quick access to the shut-off valve in the event of an emergency or when service is required. Installing the valve in such a location ensures that personnel can easily reach it without having to navigate around the appliance or disrupt any ongoing operations.

Positioning the shut-off valve in the valve train drop or riser also aligns with safety regulations and best practices. It ensures that gas flow can be safely interrupted to the appliance without complications, which is essential for maintenance and emergency situations. Accessibility is a critical factor here, and this location strikes a balance between accessibility and safety, allowing for a quick response when necessary.

In contrast, while the other options may seem viable, they do not prioritize accessibility or practicality as effectively. For example, having the shut-off valve at the customer service entrance may not be convenient in urgent situations where immediate access to the appliance is required. Similarly, installing it only near the appliance does not provide a strategic location for safety in the event of line work or emergencies that may necessitate access to the main supply line.