NItrogen distribution system welding requirements

GOOD VALIDATION PRACTICE (cGVP) EQUIPMENT VALIDATION
1

Hi,
We have a nitrogen distribution network in our sterile (injectable) plant. The piping, outside of clean rooms is made of copper (sections in clean rooms are made of SS). We are going to add a piping section with valve on the copper section of the distribution system that is located in the mechanical area. A section of the piping will be welded and I was wondering what are the requirements/specification for welds on a nitrogen distribution system on copper material ?

I have done this kind of verification on SS WFI distribution system where orbital welding is required, along with welder certificate and inspection report…

Are these requirements also applicable to copper nitrogen distribution system ?

NB. Our nitrogen is ultimately product contact.

2

You are correct about WFI piping/welding requirements.

You are also correct that N2 systems aren’t as stringent. N2 can be product contact, since they are used to blanket product But the risk is much less for the following reasons

1 - 100% N2 doesn’t promote microbial growth (while WFI can grow microbes pretty quickly)
2 - N2 typically has a sterilizing filter at point of use (WFI typcially doesn’t have this)
3 - N2 is corrosive on the welds/pipes (WFI is pretty corrosive).

I’ve seen N2 pass with a pressure test and quick weld inspection, but I’ve also seen rigorous standards and treated similar to WFI. It is based on how advanced your company is and thier internal engienering practices.