A very common question among the plumbers and homeowners that which is better PEX A or PEX B.
The question is obvious because nobody wants to change the pipework after a few months or years.
The truth is A, B or C after PEX are just the identifier for the manufacturing process, nothing to do with quality or performance.
Also, all the manufacturing processes must meet the same international standard like SDR9 dimensional standard, ASTM F876 and ASTM F877 standards.
PEX A vs PEX B
Despite the similarities, there are certain differences as the manufacturing process is different and the companies are different.
| Traits | PEX A | PEX B |
|---|---|---|
| Manufacturing Process | Peroxide (Engel) method | Silane or Moisture Cure method |
| Cross-linking Ratio | Highest degree of cross-linking among all PEX types. | Lower degree of cross-linking ratio than PEX A. |
| Crystallinity | Lower crystallinity | Higher crystallinity |
| Flexibility | Highest | Stiffer than PEX-A |
| Coil Memory | No coil memory | Noticeable coil memory |
| Bursting Pressure | Lower than PEX B | Highest among all PEX |
| Wall Thickness | Higher than PEX B | Lower than PEX A |
| Resistance | Lower than PEX B | Highest oxidative & chlorine resistance |
| Manufacturers | Uponor, Mr. PEX, Rehau | Viega, Watts,Everhot |
| Price | Lowest among all PEX | 100-160% higher than PEX-B |
Which is Better PEX A or PEX B?
As you can see in the table, there are differences between the PEX types.
But Company made them in a way so that the every PEX can provide almost similar result.
For example: PEX A has a lower crystallinity than PEX B. So, PEX A has got lower density and lower strength. To cope up with this PEX A is made with higher degree of cross linking and wall thickness.
Despite the differences, all the PEX has minimum minimum bending radius, temperature & pressure ratings, pipe wall thickness and ID/OD dimensions.
So, as a installer or hose owner what you need is checking the minimum performance requirements as specified by American Standards and Building Codes.
Also make sure the PEX types are third-party certified for end use application.
1. Radiant Floor Heating: Make sure pipe meet the ANSI/NSF 14 standards & marked with nsf-rfh or the actual standard.
2. Plumbing Pipework: Should be NSF-approved and marked with pw-G, NSF-61-G. Also meet the ANSI/NSF61 & ANSI/NSF372 standards, lead-free standards.
3. Chlorinated Water: Must meet ASTM F2023 compliance and imprinted on the pipe.
Hi, My name is Ralph D. Moniz. I am a plumbing service provider. You can contact with me here https://pexsystem.com/contact/. You can read to my blog by typing the word “PEX System” into Google or Yahoo.