Where must service valves be positioned according to the Water Supply Regulations?

The positioning of service valves is crucial for allowing easy maintenance and isolating parts of the plumbing system when necessary. According to the Water Supply Regulations, service valves must be positioned at inlets to all float-operated valves. This specific requirement helps ensure that maintenance can be performed effectively without needing to shut off the entire water supply. When service valves are located at the inlets of float-operated valves, it provides the ability to isolate those specific components for repair or replacement, thereby maintaining the integrity and functionality of the overall system.

The need for service valves in such locations is particularly important because float-operated valves control the water level in storage tanks and cisterns. Having a service valve at the inlet allows for troubleshooting or replacement without disrupting service to the other parts of the plumbing system, which supports efficient operation and reduces downtime.

In contrast, while the positioning of service valves at main supply points or after the pressure relief valve may also be important, it does not address the specific regulation focused on maintenance access for float-operated valves. Similarly, placing a service valve at the outlet of the storage vessel serves a different regulatory need concerning system isolation and may not directly pertain to the maintenance aspects that the Water Supply Regulations prioritize for float-operated valve systems.