Parallel and Series Control Valve

Control Valves in Parallel

The resulting K_v or C_v if two valves are installed in parallel can be calculated as

Kv_t = Kv₁ + Kv₂          (1)
where
Kv_t = resulting Kv
Kv₁ = Kv valve 1
Kv₂ = Kv valve 2

Control Valves in Series

The resulting K_v or C_v if two valves are installed in series can be calculated as

1 / (Kv_t)² =  1 / (Kv₁)² + 1 / (Kv₂)²           (2)