H4nkj
Chemical
- Jun 29, 2022
- 4
Hello all,
Long time lurker, first time poster.
I have been given a seemingly easy task but I'm hitting a wall. We have a nitrogen header piped through ISO 8 Clean Room laboratories. This is currently fed from a bulk LN2 tank and I need to disconnect that feed and supply the header from a MicroBulk LN2 tank. In the ceiling, this nitrogen header is all copper. At the point of uses in the labs, all the regulators and nozzles are stainless. I am concerned that the copper is not adequate enough for the application and it all needs to be replaced with stainless (which will be a much more difficult project).
A co-worker reached out to several old colleagues and they all asked if we reviewed ASME B31.3. I've since purchased and reviewed the standard but it wasn't much help. The standard is more revolved around the temperature and pressure ratings of different materials and little to do with how the material impacts gas quality. There is a paragraph in the "High Purity" section that states "Materials commonly used in high purity process piping systems include austenitic, ferritic, and duplex stainless steels, and nickel and nickel alloys," but this doesn't seem like enough to hang my hat on.
I also came across another post from this forum. Commenters were pretty unanimous that 316 SS is the 'industry standard' for that application but no one produced any specifications to back this up.
I reviewed the ISO 14644-1 (Classification of air cleanliness by particle concentration) and ISO 14644-4 (Design, construction and start-up). Everything revolves around air particulate count and the design and construction section only talks about materials used to construct the room (floors, walls, benchtops) and nothing about gas headers. In my application, the nitrogen will be used as an agitator under a fume hood and used to pressure transfer the product from a filter to collection vessel. In the pressure transfer step of the process, the N2 will be vented into the room. The nitrogen purity is 99.999% at delivery. If we can determine that 99.999% nitrogen in copper tubing will not have a negative quality impact on our product, I'm wondering if I can just install a particulate filter at every point of use to avoid raising the particulate count and effecting the ISO 8 clean room status.
Any comments or guidance would be appreciated. I would love to find a standard that I could use to defend my decision.
Long time lurker, first time poster.
I have been given a seemingly easy task but I'm hitting a wall. We have a nitrogen header piped through ISO 8 Clean Room laboratories. This is currently fed from a bulk LN2 tank and I need to disconnect that feed and supply the header from a MicroBulk LN2 tank. In the ceiling, this nitrogen header is all copper. At the point of uses in the labs, all the regulators and nozzles are stainless. I am concerned that the copper is not adequate enough for the application and it all needs to be replaced with stainless (which will be a much more difficult project).
A co-worker reached out to several old colleagues and they all asked if we reviewed ASME B31.3. I've since purchased and reviewed the standard but it wasn't much help. The standard is more revolved around the temperature and pressure ratings of different materials and little to do with how the material impacts gas quality. There is a paragraph in the "High Purity" section that states "Materials commonly used in high purity process piping systems include austenitic, ferritic, and duplex stainless steels, and nickel and nickel alloys," but this doesn't seem like enough to hang my hat on.
I also came across another post from this forum. Commenters were pretty unanimous that 316 SS is the 'industry standard' for that application but no one produced any specifications to back this up.
I reviewed the ISO 14644-1 (Classification of air cleanliness by particle concentration) and ISO 14644-4 (Design, construction and start-up). Everything revolves around air particulate count and the design and construction section only talks about materials used to construct the room (floors, walls, benchtops) and nothing about gas headers. In my application, the nitrogen will be used as an agitator under a fume hood and used to pressure transfer the product from a filter to collection vessel. In the pressure transfer step of the process, the N2 will be vented into the room. The nitrogen purity is 99.999% at delivery. If we can determine that 99.999% nitrogen in copper tubing will not have a negative quality impact on our product, I'm wondering if I can just install a particulate filter at every point of use to avoid raising the particulate count and effecting the ISO 8 clean room status.
Any comments or guidance would be appreciated. I would love to find a standard that I could use to defend my decision.
