Plate Heat Exchangers Base Specification, Rev 0 Version 1.0

Overview

Written by authors from Alfa Laval, Wieland, Kelvion and Danfoss, the specification defines the standard to which plate heat exchangers must be designed and supplied for OCP-ready facilities. The scope covers white space (CDUs, immersion, direct-to-chip, single- and two-phase cooling), grey space (chillers, interchangers between cooling towers or dry/adiabatic coolers and sources such as river, sea or borehole water) and heat-recovery interfaces such as district heating, greenhouses and swimming pools.

General requirements sit in the environmental and regulatory section. The complete assembly must be designed and manufactured to PED 2014/68/EU, ASME BPVC Section VIII Division 1 or local rules specified by the client, with certification for both circuits. ISO 9001 applies to production; REACH/RoHS and ISO 14001, 45001, 14025, 14040/14044, 14067 and 50001 are listed for environmental and safety compliance. Every unit needs an Environmental Product Declaration. Thermal lab testing is optional; minimum documents are a declaration of conformity, a pressure test certificate, a manual in the regional language and 2D/3D drawings on request.

One advisory design parameter covers all types: wall shear stress (Tau) should be chosen by application, with a suggested target of 25 Pa. Higher values create more turbulence and suit fouling-prone duties such as open cooling towers and seawater; lower values can suit clean DTC/CDU loops. The label must carry supplier, model, serial number, test date, place of manufacture, minimum and maximum operating temperature, design pressure, volume and graphical hot/cold port identification.

For gasketed (plate-and-frame) units the test pressure must be stated: for connections up to DN100, 10 minutes at test pressure; above DN100, 10 minutes plus 20 minutes at working pressure; both sides get an unbalanced pressure test. Units must be AHRI liquid-to-liquid certified, nozzle velocity is capped at 6.5 m/s, frames must be fully bolted (no welded frames) with individual plates removable, and spares must be available for 10 years. Plates are 316/316L, 304/304L or titanium; gaskets are one-piece moulded nitrile, EPDM or FKM with relief grooves.

For copper-brazed and alternative bonded units the test pressure is 1.43 x service pressure under PED/CE and design pressure under UL. Single-phase units are tested with air or helium, two-phase units leak-tested with helium per EN 1779:1999. The options are 316L plates with at least 99.9% copper braze, nickel-based braze, or 100% stainless units bonded without copper or nickel; nozzle velocity is limited to 5.5 m/s. Appendix A's chloride and pH water-quality graphs are informative and non-binding.

Key points

1. Scope spans CDUs, DTC and immersion systems, chillers, tower/dry-cooler interchangers, natural-water free cooling and heat-recovery separation circuits.
2. Assemblies must follow PED 2014/68/EU or ASME BPVC Section VIII Div. 1 and be tested to that code; every unit needs an EPD.
3. Suggested wall shear stress (Tau) target is about 25 Pa; higher for fouling-prone duties, lower for clean DTC/CDU loops.
4. Gasketed units: both sides unbalanced pressure test; 10 minutes up to DN100, 10 minutes plus 20 minutes at working pressure above DN100.
5. Gasketed units must be AHRI liquid-to-liquid certified, with nozzle velocity at most 6.5 m/s and spares available for at least 10 years.
6. Frames must be fully bolted; welded frames and welded reinforcements are not permitted, and single plates must be removable without moving adjacent plates.
7. Plates are Alloy 316/316L, 304/304L or titanium; gaskets are one-piece moulded nitrile, EPDM or FKM with leak-relief grooves.
8. Brazed units: test pressure 1.43 x PS (PED/CE) or design pressure (UL); two-phase units helium leak-tested per EN 1779:1999.
9. Brazed options: copper-brazed (316L, at least 99.9% copper), nickel-brazed, or 100% stainless without copper or nickel; nozzle velocity limit 5.5 m/s.
10. Labels must show design pressure, operating temperature range, volume and clear hot/cold stream identification.

Using it in design

• Record in catalogue entries the type (gasketed/brazed), plate and gasket materials, AHRI certification, design pressure and temperature, code (PED/ASME) and EPD embodied carbon.
• Flag copper-brazed units on loops whose fluid chemistry or material-compatibility rules exclude copper, and consider nickel-brazed or 100% stainless alternatives.
• Prefer serviceable gasketed units with a higher Tau on fouling-prone condenser or open-tower loops.
• Reserve plate-withdrawal service space for gasketed frames in plant-room layouts.
• Add the nozzle-velocity limits (6.5 m/s gasketed, 5.5 m/s brazed) to the hydraulic selection checklist.
• Verify plate material (316L, 304 or titanium) against water chloride level using the Appendix A graphs.

Who should read it

Mechanical design engineers and suppliers specifying or selecting plate heat exchangers for CDU and cooling-plant duties.

Document contents

1. License
2. Compliance with OCP Tenets
3. Change Log
4. Overview
5. Environmental / Regulatory Requirements
6. Pressure vessel code requirements/options
7. Quality standards for production
8. Environmental and Safety Standards
9. Plate heat exchangers (General)
10. Mandatory Product Label Information
11. Gasketed Plate Heat Exchangers
12. Design Standards
13. Frame Specification
14. Channel plate Specification
15. Gasket Specification
16. Copper Brazed and Alternative Bonded Material Plate Heat Exchangers
17. Appendix A - Water Quality Graphs; Chloride and pH

Related standards

• PED 2014/68/EU
• ASME BPVC Section VIII Div. 1
• AHRI Standard 400
• ASTM B170

Read the document

Publication details

Authors

Reeves, G. (Alfa Laval); Hudelmaier, F. (Wieland); Verma, A. (Kelvion); Padhmanabhan, S. (Danfoss)

Publisher

Open Compute Project Foundation

Year

2025

Document number

Rev 0 v1.0

Document language

English

Source type

Industry body

Access

Open licence — downloadable

Licence

OWFa 0.9 — Open Compute open specification licence; redistribution permitted

Licence evidence

www.opencompute.org

Citation