Static balancing valve Termojet DN25 (Rp 1") SBV

The Termojet SBV DN25 static balancing valve is the largest size in the SBV range, designed for hydraulic balancing of main pipelines and large heating or cooling circuits. Connection Rp 1" (internal thread), flow coefficient Kvs 8.59 m³/h at four spindle turns, maximum pressure PN 20 bar, temperature range –20…+120°C. Body — brass CW617N, EPDM seals, working fluid — water or glycol up to 50%. All in one body: balancing, pre-setting, measurement and shut-off.

Technical Specifications

Operating Principle

The valve is installed on the return main pipeline or a large-diameter distribution manifold. Rotating the spindle from 0 to 4 turns sets the flow cross-section corresponding to the required heat-carrier flow rate. At maximum opening the flow capacity is Kvs 8.59 m³/h — sufficient for balancing large heating circuits. Built-in measuring nipples allow connecting a differential pressure gauge without installing additional fittings. The set spindle position is locked and retained during service openings of the valve. The shut-off function allows the main line to be fully closed for system maintenance.

Applications

• Main distribution manifolds. SBV DN25 is installed at the outlets of the main boiler room manifold to balance between the primary building zones — floors, wings or functional blocks.
• Multi-storey residential buildings, office and shopping centres. Balancing large-diameter risers — each floor or section receives the calculated heat-carrier flow rate, and thermal comfort is equalised throughout the entire facility.
• Underfloor heating systems for large areas. For balancing between several underfloor manifolds in buildings of 200+ m² or commercial facilities.
• Industrial cooling and air conditioning. Rp 1" and Kvs 8.59 cover flow rates in centralised chiller systems for production and warehouse premises.
• DHW boilers and heat exchangers. Balancing the flow through the water heater relative to the main heating circuit — ensures DHW priority without installing an additional controller.

Advantages of Termojet SBV DN25

• Kvs 8.59 m³/h — the highest value in the SBV range: covers flow rates for circuits with a capacity of up to 50–60 kW at a standard 10°C differential.
• PN 20 bar — maximum pressure with no restrictions for commercial and industrial systems with elevated operating pressure.
• Full function set — balancing, pre-setting, nipple measurement and shut-off in one assembly instead of four separate devices.
• Glycol up to 50% — reliable operation in antifreeze systems, including geothermal circuits of heat pumps.
• Brass CW617N and EPDM — a combination that meets the standards of leading balancing valve manufacturers, without import mark-ups.

SBV DN25 and the Heat Pump

Systems with a heat pump and an extensive network of underfloor heating or fan coils are particularly demanding in terms of hydraulic balancing: even a minor flow imbalance increases the load on the circuit pump and reduces heat transfer efficiency. The Termojet SBV DN25 valve on the main distribution manifold ensures uniform supply of low-temperature heat carrier to every zone — the heat pump operates at its optimum operating point and the COP increases. For more information on system design and equipment selection, visit the Termojet heat pumps website.

Frequently Asked Questions

Which SBV size to choose: DN15, DN20 or DN25?
Base your choice on the pipeline diameter and the calculated circuit flow rate. DN15 (Kvs 2.56) — for apartment unit connections and small branches; SBV DN20 (Kvs 5.39) — for medium-capacity risers and branches; DN25 (Kvs 8.59) — for main distribution pipelines and large circuits. If the circuit flow rate exceeds 80% of the Kvs of the selected valve, choose the next size up.

Is a balancing valve needed if the system is already in operation?
Yes, and often precisely then. If some rooms fail to reach temperature or the system is noisy — these are signs of hydraulic imbalance. Installing an SBV on each circuit and adjusting based on differential pressure gauge readings equalises the flow without replacing pipes or the pump. View the full range of balancing valves in the Termojet balancing valves — catalogue.