Does the service main have a PRV? I'm assuming the building is tied into the public water main. Was there any recent changes to the public service, increase flow or pressure? Were new fixtures (ie flush valves) added that required more pressure?
The IPC does not directly state the type of connection to the sanitary system. In fact 411.2 states: Waste connections shall not be required for emergency showers and eyewash stations. The thought behind this is that if there is an accident, it can be properly contained without affecting the...
