Danfoss XB52M-2 36/36 2-pass brazed plate heat exchanger, G 2", 72 plates, PN 25
- Application: 2-stage DHW (stage I — preheating from district heating return, stage II — post-heating to setpoint)
- Heat capacity: ~55-125 kW (depending on flow and ΔT)
- Nominal pressure: PN 25 (25 bar) — both circuits
- Connection: G 2" external thread (ISO 228/1)
Where XB52M-2 36/36 is used
The 2-pass XB52M-2 is designed for DHW production in district heating substations where maximum utilisation of the district heating return temperature is required. In stage I, cold potable water is preheated by the district heating return flow (typically 40–55 °C); in stage II, it is post-heated by the supply flow to the setpoint (usually 55–60 °C). This scheme lowers the district heating return temperature — important both for network operational efficiency and where the utility applies penalties for excessive return temperatures.
Typical applications: apartment block substations with DHW demand ~55-125 kW, schools, hotels, offices, industrial buildings.
Technical specifications
| Parameter | Value |
|---|---|
| Code | 004H4543 |
| Series | Danfoss XB52M-2 (Micro Plate™, 2-pass) |
| Model | XB52M-2 36/36 |
| Number of plates (stage I / II) | 36 / 36 (total 72) |
| Nominal pressure (PN) | 25 bar (both circuits) |
| Connection | G 2" external thread (ISO 228/1) |
| Plate material | Stainless steel 1.4404 (AISI 316L) |
| Brazing filler | Copper |
| Temperature range | -196 … +180 °C |
| Height (without feet) | ~684 mm |
| Width | 256 mm |
| Weight | ~28.0 kg |
| Construction | Brazed, hermetic (gasket-free); 2-pass design with divider plate |
| Certification | PED 2014/68/EU, category II |
| Media | Water, glycol solutions; potable water on secondary side |
Heat transfer capacity — quick calculation
Capacity depends on flow rate, ΔT and log mean temperature difference. General formula: P = Q × ΔT × 1.163 (kW, Q m³/h, ΔT °C).
DHW example: with secondary potable flow Q = 1.8 m³/h (cold 10 °C → hot 55 °C, ΔT ≈ 45 °C) → P ≈ 94 kW. Real capacity headroom depends on the primary (district heating) supply schedule and stage balance.
When to choose XB52M-2 36/36
- District heating substation DHW system with capacity demand ~55-125 kW
- When the utility imposes limits or penalties on district heating return temperature
- Apartment blocks, schools, office buildings, hotels — where DHW peak demand matters
- When a compact, maintenance-free solution is required (brazed gasket-free construction)
- Compatibility: typical package — Danfoss ECL Comfort 310 controller + AME actuator + VF/VFG regulating valve + ESMU/ESMT sensors
B2B delivery and logistics via Amegata.lt
- 24-hour delivery across Lithuania (from our warehouse in Vilnius)
- Competitive B2B pricing — often below market average
- 30-day payment terms for companies (per contract)
- Free technical consultation for sizing selection (HEXact calculation)
Official Danfoss catalogue: store.danfoss.com/p/004H4543
Frequently asked questions
How does a 2-pass exchanger differ from a single-pass one?
In a 2-pass exchanger the primary flow passes through two sections separated by a divider plate. In DHW applications this allows the returning primary flow's energy to be used for initial water preheating — the district heating return temperature drops and system exergy efficiency rises. Where the district heating utility controls return temperature, a 2-pass scheme is often mandatory.
Can glycol mixtures be used?
Yes, on the primary (district heating) side — ethylene or propylene glycol solutions up to 50 %, with appropriate inhibitors. On the secondary (potable water) side glycol is not allowed — only potable-grade water.
What maintenance is required?
The brazed gasket-free construction requires no periodic disassembly. Recommended only CIP (Clean-in-Place) chemical flushing every 3–5 years or sooner if fouling signs appear (rising pressure drop, falling heat transfer). Use food-safe cleaning agents on the potable secondary side.
Is it suitable for potable water?
Yes. Stainless steel 1.4404 plates and copper brazing meet potable water system requirements (EN, DVGW, WRAS and similar certifications). Per PED — Fluid Group 1 (copper brazing, TP scheme).
Is it suitable for regions with aggressive (chloride / ammonia) water?
District heating water in some Lithuanian regions contains elevated chlorides or ammonia — copper brazing may shorten service life. Alternative — Danfoss XB models with stainless steel brazing (nickel / SS variants) or Alfa Laval AlfaNova. For hard water with elevated Ca/Mg carbonate content, limescale gradually builds up on the plates and reduces heat-transfer efficiency; for such systems gasketed (plate-and-frame) exchangers are preferable, as they can be periodically opened for mechanical or CIP cleaning. Contact us — we will select a model suited to your water conditions.
