IPC 607.3

IPC 604.8 / Manufacturer installation requirements

IPC Section 604.8 and manufacturer requirements mandate a strainer upstream of every PRV to prevent debris from fouling the valve seat. Without a strainer, particulate in the water supply causes the PRV to fail — either stuck open (allowing dangerously high pressure downstream) or stuck closed (cutting off water supply to the zone).

IPC 605.11.2

Lead solder is prohibited on any pipe or fitting in a potable water system. Only lead-free solder (0.2% maximum lead content) may be used per the Safe Drinking Water Act and plumbing codes.

IPC 605.24

Dissimilar metals (steel valve body to copper pipe) must be joined with a dielectric fitting to prevent galvanic corrosion.

IPC 607.3 (thermal expansion control) / project specification

Don't misread the code here. IPC 604.8 only governs WHEN a pressure-reducing valve is required (static pressure over 80 psi) plus its setting/bypass rules — it does NOT mandate a relief valve downstream of each PRV. The actual code requirement is thermal-expansion control on the closed system per IPC 607.3, which is normally satisfied by an expansion tank at the water heater/closed zone, not a relief valve at every PRV. A downstream relief valve at a high-rise PRV station is still good practice / spec: if the PRV fails open, piping and fixtures rated for 80 psi could see 150+ psi. Know what code mandates (expansion control, IPC 607.3) versus what the spec adds (PRV-failure relief).

IPC 607.3.2

When a backflow preventer or check valve is installed on the water service (creating a closed system), a thermal expansion tank is required. Without it, heated water expanding has nowhere to go and can cause dangerous pressure buildup.

IPC 608.1

A garden hose submerged in a pool creates a direct cross-connection. If a back-siphonage event occurs, contaminated pool water can be drawn into the potable supply. Hose bibbs must have vacuum breakers and hoses must never be submerged.