Category M equivalent in EN 13480

[gatossi]

We are designing a process plant under EN 13480, one of the fluid is Hydrogen Cyanide and our HSE team has deemed it as a "Category M fluid". As far as I am aware, Category M is not defined as such under EN 13480 (or PED).

Am I missing anything in EN13480 that lays down rules for designing a Lethal Fluid piping system?
if not, I am planning to use B31.3 Chapter VIII as a "guide" (although our material selection shows a non-metallic for this fluid, which is explicitly prohibited in Chapter VIII) but I am not sure how a NoBo will take this.

 

[XL83NL]

Afaik, EN 13480 doesn't have this. I can't imagine that a NoBo may have any rejection on your proposal, as long as the Cat M requirements are additional and/or more stringent than EN 13480 requirements. Point of attention may for example be the NDE acceptance criteria. If B31.3 is more stringent, it can be a challenge to get all the details in a properly revised NDE procedure and have the NDE guys follow those rules (since they deviate from their standard work, that is where it may become difficult to make sure you follow the procedure - its become non-standard).

The 'PED substantiation' for B31.3 fluid service, if you like to call it like that, is that the PED category will define additional requirements for stuff like NDE, pipe supporting, etc based on the testing group.

Afaik, EN 13480-5 para 8.2.1 knows 3 service levels; standard, creep and fatigue. There isnt more differentation.



Huub
- You never get what you expect, you only get what you inspect.