Decoding PSI Ratings: Key Differences Between ASME and PED Standards

What if we told you that there is more than one standard pressure rating system for manufacturing equipment?

If this is news to you, it could completely change the way you look for a plate heat exchanger solution.

While all industries follow best manufacturing practices, American companies often use plate heat exchangers rated by the American Society of Mechanical Engineers (ASME). Whereas those overseas usually work with the European Pressure Equipment Directive (PED). If you aren't familiar with both measurements, it’s easy to misinterpret the difference between them.

So, let’s talk about what to look for in your plate heat exchanger pressure rating (and how to know you’re getting the right durability for your product and process).

ASME vs. PED Pressure Ratings

Pressure ratings help you determine how much pressure your equipment can handle under normal production conditions. Chances are you’ve seen at least one of the two PSI types as you’ve shopped around for a heat exchanger:

• The American Society of Mechanical Engineers (ASME) code is commonly used in North America
• The European Pressure Equipment Directive (PED) code is standard in Europe

What few people know is that ASME and PED codes are not interchangeable. 

Take AGC’s PRO8-SA frame rated with both ASME and PED code, for example:

Wondering why the max PSI rating is lower for the same exact frame using ASME? It’s not! It just uses a different design calculation.

ASME code also requires more robust materials in comparison to PED code, meaning the structural steel used to create the frame is thicker.

If you compare two plate heat exchangers with the same PSI rating, one is 200 ASME and the other is 200 PED; the ASME-rated frame will be built stronger than the frame with the same rating in PED. As a result, PED-rated frames tend to be less expensive. As you can see in this image, it's possible to experience a connection failure caused by excess pressure on a frame if the rating is misinterpreted.

Awareness of the multiple PSI ratings is the best way to inform yourself and ensure you are finding the best solution for your manufacturing needs as a plate heat exchanger buyer.

Plate Heat Exchanger Pressure Ratings Aren’t All the Same

Pressure ratings have been the wild west of the plant equipment world for decades. 

At AGC, each of our custom plate heat exchangers can be rated using ASME or PED code to help you make the best buying decision for your manufacturing needs.

Interested in seeing what we can bring to your plant? All of our plate heat exchanger frames are made right here in the United States, along with an entire line that uses ASME design criteria.