Ball Valves for HVAC & Building Services

For chilled water HVAC systems with 20–40% propylene or ethylene glycol antifreeze, brass 2-piece ball valves (PTFE seats, chrome-plated brass ball, DZR brass body) to PN16 are the standard choice for DN15–DN50. For DN50–DN150 headers, carbon steel ASME B16.34 Class 150 ball valves with PTFE seats work well. SS 316L should be used for: (a) coastal buildings where chloride corrosion of brass is a risk; (b) systems using ethylene glycol treated with corrosive inhibitors; (c) pharmaceutical or laboratory buildings where contamination risk is a concern. Avoid standard yellow brass in ethylene glycol systems with high pH treatment chemicals — dezincification risk. The glycol itself (propylene or ethylene at 20–40%) is compatible with PTFE seats, Viton O-rings, and carbon steel/SS 316L bodies. Ensure the ball valve pressure-temperature rating covers the chiller plant design pressure (typically 10–16 bar working pressure for multi-storey systems).

Under PED 2014/68/EU (Pressure Equipment Directive), ball valves used in building services are classified as 'pressure accessories.' The CE marking requirement depends on nominal size and maximum allowable pressure (PS): Group 2 fluids (water, glycol, air — non-hazardous) require CE marking for ball valves DN25 and above at PS > 0.5 bar; Group 1 fluids (steam) require CE marking from DN10 at PS > 0.5 bar. For very small HVAC ball valves (DN15–DN20 water/glycol), CE marking is not required, but the manufacturer must still comply with Good Engineering Practice (GEP). In practice, reputable HVAC valve manufacturers CE-mark their entire range from DN15 upwards for market acceptance. For heating systems in Germany, the DIBt approval and DVGW certification may also be required. Always request the Declaration of Conformity (DoC) and CE certificate from the valve supplier for all PED-covered valves.

Yes, ball valves can be used for steam isolation in commercial HVAC steam heating systems, subject to correct specification. Key requirements for steam service ball valves: (1) ASME B16.34 rated — Class 150 covers up to 10.2 bar at 399°C steam; Class 300 for higher pressure steam; (2) Body material: SS 316 or carbon steel WCB — NOT brass/bronze above 3 bar steam (dezincification risk; brass limited to low-pressure steam below 1.5 bar per most specifications); (3) Seat: PTFE with a carbon-fibre or glass-fibre reinforced compound for steam to 200°C — pure PTFE softens at 260°C; metal seat required above 260°C; (4) Packing: Graphite-reinforced PTFE or pure graphite for steam service — avoid pure PTFE packing above 200°C; (5) Position: Ball valves should NOT be used for steam throttling — they are ON/OFF isolation only; steam control requires globe or V-port ball valves. Ball valves on steam condensate return lines (80–100°C flash steam + condensate) are completely standard — SS 316L or WCB body, PTFE seats.