KOSA Filtration · Thermal Equipment
Sanitary Plate Heat Exchanger Selection Guide
How to select a sanitary plate heat exchanger: counter-flow principle, sizing inputs (kW, LMTD, pressure drop, fouling), 316L plates, NBR/EPDM/FKM gaskets, and hygienic disassembly for CIP.
Key Takeaways
- A sanitary plate heat exchanger (PHE) transfers heat through thin corrugated 316L plates in counter-flow — high U-values in a small footprint.
- Sizing is driven by duty (kW), LMTD, allowable pressure drop and fouling — not plate count alone.
- Gasket choice (NBR / EPDM / FKM / FKM-FDA) sets the temperature and food-contact limit; frames and plates are typically 316L, Ra ≤ 0.8 µm for hygienic duty.
What a sanitary plate heat exchanger is
A plate heat exchanger is a stack of thin, corrugated metal plates clamped in a frame. Two fluids flow in alternate channels; heat passes through the plate walls without mixing.
In hygienic service the plates are 316L stainless with a smooth electropolished surface, and the unit is built to dismantle for CIP and inspection — that is what makes it "sanitary" versus an industrial shell-and-tube unit.
How it works (counter-flow)
Plates are gasketed so fluid A and fluid B enter at opposite ends and flow past each other in opposite directions. Counter-flow gives the highest log-mean temperature difference (LMTD) for a given duty, so a PHE reaches the same kW in a fraction of the footprint of a shell-and-tube exchanger. Corrugations induce turbulence at low Reynolds number — high heat-transfer coefficient with low fouling.
What you need to size one
| Input | Why it matters |
|---|---|
| Thermal duty (kW) + inlet/outlet T | Sets heat-transfer area and LMTD |
| Flow rates of both streams | Drives velocity, pressure drop, turbulence |
| Allowable pressure drop | Limits plate count and channel width |
| Fouling factor | CIP frequency / product viscosity margin |
| Service fluids + temperature | Selects gasket and plate alloy |
Plates and gaskets
| Part | Typical choice | Note |
|---|---|---|
| Plate | 316L (UNS S31603) | Ra ≤ 0.8 µm; Ti or 904L for aggressive duty |
| Gasket | NBR / EPDM / FKM | EPDM: -40~150°C; FKM: higher T, some food grades |
| Frame | 304 / 316L | Clamp pressure distributed evenly |
Gasket temperature and extraction limits define the safe operating envelope — confirm against your product and CIP chemistry before specifying.
Hygiene and cleanability
A sanitary PHE is selected for easy disassembly: plates and gaskets come out for visual inspection and CIP. Single-pass, wide-gap plate geometries are available where the product is viscous or contains particles. Where 3-A or EHEDG alignment is required, confirm the model and gasket material meet the relevant guidance before purchase.
Need a sanitary PHE sized?
Send KOSA your duty, temperatures, flow rates and fluids — we return a plate count, gasket choice and footprint.
Request a quoteRelated: Electropolished 316L pipe · ASME BPE vs 3-A standards · Technical bulletins
Frequently asked questions
What is a sanitary plate heat exchanger?
A stack of thin corrugated 316L plates in a clamped frame. Two fluids flow in alternate counter-flow channels and exchange heat through the plates without mixing. It is built to dismantle for CIP and inspection.
How do I size a sanitary PHE?
From thermal duty (kW) and inlet/outlet temperatures (sets area and LMTD), both flow rates (velocity, pressure drop), allowable pressure drop, fouling factor, and the two service fluids/temperatures (selects gasket and plate alloy).
Which gasket for food contact?
EPDM covers roughly -40 to 150°C and is common for food/CIP; NBR for lower temperature oils; FKM for higher temperature and some aggressive duty. Confirm extraction limits and CIP compatibility before specifying.
Authoritative references
- 3-A Sanitary Standards
- ASME BPE — Bioprocessing Equipment
- ASTM A270 — sanitary tubing (plate alloy reference)
Request a Quote from KOSA
Tell us about your 316L stainless piping, filtration, valve or heat-exchanger requirements. The responsible KOSA specialist will get back to you with a quotation and technical proposal.