Hexonic LB31-70H-1 brazed plate heat exchanger, 1", 70 plates, PN 30
- Application: primary/secondary loop separation — district heating, DHW, process
- Heat capacity: ~105-210 kW (depending on flow rate and ΔT)
- Nominal pressure: PN 30 (30 bar)
- Connection: G 1" external thread (both sides)
Where LB31 LB31-70H-1 is used
The 70-plate Hexonic LB31 exchanger is typically selected for: multi-family substation user branches, domestic hot water (DHW) primary exchanger for small-to-medium systems, underfloor heating loop separation, fireplace with water jacket separation. The brazed gasket-free construction requires no periodic disassembly maintenance that gasketed exchangers would need. The compact housing (plate 286 × 113 mm, depth 174.5 mm) fits even in small technical rooms.
Technical specifications
| Parameter | Value |
|---|---|
| Code | 0203-0642 |
| Series | Hexonic LB31 |
| Model | LB31-70H-1 |
| Number of plates | 70 |
| Plate profile | H (higher chevron angle) |
| Passes | 1 (1-pass, 4 connections) |
| Nominal pressure (PN) | 30 bar |
| Max working temperature | 230 °C |
| Min working temperature | -195 °C |
| Connection | G 1" external thread (S1-S4) |
| Plate material | Stainless steel AISI 316L (1.4404) |
| Brazing filler | Copper (Cu) |
| Plate dimensions | 286 × 113 mm |
| Unit depth (F) | ~174.5 mm (formula: 10 + 2.35 × N, N = 70) |
| Weight | ~9.6 kg |
| Construction | Brazed, hermetic (gasket-free) |
| Media | Water, glycol solutions up to 50 %, other media compatible with stainless steel and copper |
Heat transfer capacity — quick calculation
Capacity depends on flow rate, ΔT and logarithmic mean temperature difference (LMTD). General formula: P = Q × ΔT × 1.163 (kW, Q m³/h, ΔT °C).
Example for heating mode (primary 90/70 °C → secondary 65/40 °C): at Q ≈ 6.8 m³/h and effective ΔT ≈ 20 °C → P ≈ 157 kW. With higher flow and wider ΔT, capacity scales linearly up to the plate area limit.
When to choose LB31-70H-1
- When ~105-210 kW capacity range is needed
- When a compact, gasket-free hermetic construction is preferred
- When the working media are water or glycol mixtures (up to 50 %)
- When budget constraints favor brazed over gasketed, and service conditions allow copper brazing
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
Official Hexonic catalogue: hexonic.com/brazed-plate-exchangers/L
Frequently asked questions
What does "H" mean in Hexonic model codes?
"H" denotes a higher plate chevron angle — higher heat transfer coefficient, higher pressure drop. Standard (no "H") variant — lower Δp, less intensive transfer. "H" is preferred for higher-ΔT service; standard for lower-flow systems.
Can glycol mixtures be used?
Yes. Hexonic LB31 series is compatible with ethylene glycol and propylene glycol solutions up to 50 %, when appropriate inhibitors are used. For DHW — only potable-grade fluids allowed.
What maintenance is required?
Brazed gasket-free construction requires no periodic disassembly maintenance. Recommended only CIP (Clean-in-Place) flushing every 3-5 years if fouling signs appear (rising pressure drop or falling heat transfer).
Is it suitable for potable water?
Yes. Stainless steel AISI 316L plates and copper brazing meet potable water system requirements (WRAS, DVGW and similar certifications, depending on country).
Is it suitable for regions with aggressive water?
In some regions, district heating water contains elevated chlorides or ammonia — in such systems, copper brazing may shorten service life. In these cases we recommend the Hexonic Luna series (stainless steel brazing, copper-free) or gasketed plate exchangers with EPDM/NBR gaskets. 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 the model best suited to your water conditions.
Is insulation needed?
In heating systems where heat losses to the room should be minimized, the APFI series insulation shell is recommended (polyurethane foam with aluminum cover, up to 135 °C). In substations, insulation is nearly a default choice.
