California Code of Regulations (Cal. Code Regs.): Title 24 – California Building Standards Code > Cal. Code Reg. §3120B.17 Direction of flow.
§3120B.17.1 (no title)
The direction of flow for the recirculation equipment shall be labeled clearly with directional symbols such as arrows on all piping in the equipment area.
§3120B.17.2 (no title)
Where the recirculation equipment for more than one pool is located on site, the equipment shall be marked as to which pool the system serves.
§3120B.17.3 (no title)
Valves and plumbing lines shall be labeled clearly with the source or destination descriptions.