Valves and flow equipment for district heating systems

District heating systems transfer thermal energy from a central heat source to buildings, industrial facilities and substations through hot water or steam networks. Their operation depends on controlled flow, pressure and temperature in the supply and return lines, as well as safe isolation of individual network sections.

Valves in district heating installations are selected according to operating temperature, design pressure, differential pressure, required flow rate, network length and substation operating conditions. Correct sizing helps limit pressure losses, hydraulic instability, noise and temperature deviations at consumer connection points.

Typical applications

• Main hot water supply and return networks.
• Steam and condensate networks in steam-based district heating systems.
• Building substations with heat exchangers and domestic hot water circuits.
• Heat generation stations with boilers, CHP, biomass or geothermal sources.
• Bypass, filling, draining and venting lines.
• Circulation pumping stations, pressure regulation stations and hydraulic balancing points.
• Auxiliary compressed air, treated water and automation networks.

Equipment selection criteria

• Network supply and return temperature.
• Operating pressure, design pressure and valve differential pressure.
• Required flow rate and allowable pressure drop.
• Material compatibility with hot water, steam, condensate or treated network water.
• Isolation, control, non-return, balancing or protection function.
• Resistance to thermal expansion, load cycles and demand variations.
• Remote operation, position indication and connection to BMS or SCADA systems.
• Access for inspection, maintenance and isolation of network sections.

Indicative equipment

• Isolation valves for main supply and return lines.
• Control valves for flow, temperature and differential pressure regulation.
• Balancing valves for hydraulic adjustment of branches and substations.
• Pressure reducing valves and differential pressure regulators for stable operation.
• Check valves for pump protection and backflow prevention.
• Safety and relief valves for protection of networks, vessels and heat exchangers.
• Steam traps and condensate equipment in steam networks.
• Line strainers for protection of heat exchangers, control valves, pumps and instruments.
• Electric and pneumatic actuators for remote and automated operation.

For each installation, the thermal load, supply and return temperature difference, differential pressure, installation point, isolation requirement and network control logic should be reviewed. These data define the valve type, nominal size, pressure class, construction materials, tightness requirements and suitable actuation method.