HVAC systems use a swing check valve to prevent reverse flow in chilled water loops. The low head loss of a swing check valve makes it energy efficient. A bronze swing check valve is common for closed loop hydronic systems.

The disc of a swing check valve opens with a very low cracking pressure (0.5 psi). For vertical risers, a spring‑assisted swing check valve ensures closing even at low flow. The hinge of a swing check valve should be lubricated for quiet operation.

When multiple chillers are paralleled, each pump discharge needs a swing check valve. A non‑slam swing check valve reduces water hammer in long piping runs. The body of a swing check valve can be insulated to prevent condensation.

In a cooling tower bypass, a swing check valve prevents mixing of supply and return water. The seat material of a swing check valve is often EPDM for HVAC use. A 4‑inch swing check valve in a 12‑inch line would create pressure drop.

Therefore, sizing a swing check valve correctly is important. Some swing check valve models have a visual position indicator. For glycol mixtures, a stainless steel swing check valve resists corrosion.

The cover plate of a swing check valve can be removed for inspection without taking the valve out. A spring‑loaded swing check valve is also called a “silent” check valve. In variable flow systems, a swing check valve with a damped hinge reduces clatter.

Installing a swing check valve backwards will block flow completely. The arrow on a swing check valve must point downstream. For low temperature applications, a swing check valve with extended bonnet prevents freezing. A properly selected swing check valve lasts the life of the HVAC system.