Ultrahigh Purity Gas Specification 3

[PEDARRIN2]

I am writing/editing a specification for an ultrahigh purity nitrogen system for a series of adjoining class 100 clean rooms.

The project is a design build so there is an installing contractor on board.

I was given a standard specification (15481) to serve as the basis of my specification. I found a similar specification for a Sandia Labs project.

In the specification, there is a section that requires field flushing the piping whenever a cut is made to the pipe.

The pipe is to be flushed with an alcohol/DI water mix and blown dry with 0.01 micron nitrogen from a cryogenic source. The contractor is balking at this section since he feels, due to the nature of the installation, which has a main routing through the facility with branches to the individual rooms (all of which are in a clean room environment), requiring many field cuts - that it would not be possible to get the piping completely dry with the nitrogen.

Since there was the specification from Sandia, I am thinking that it might be possible to do this but I have no way of knowing if the Sandia contractor was held to this requirement in the specification. There is a section where the inspector/QC representative can make modifications.

I need to know if somebody has any experience with this type of work that could help me to determine if the requirement is valid and the contractor is just being lazy.

I have also posted this question on a clean room forum - but wanted to see if anybody here could help.

 

[BigInch]

Why make specifications if the contractor won't have to follow them. I doubt Sandia is in the habit of wasting time with meaningless specifications.

 

[PEDARRIN2]

I don't know if the Sandia project was a design/build like mine. If it was a bid project, the contractor would have to follow the specification in order to get the job.

In my case where the contractor and I are on the same "team", he already has the job - he is questioning the requirements.

He has done specialty gases - just not in a semi conductor clean room environment. He can do the welding and other stuff - he is just questioning the requirment for the field flushing with the alcohol and DI and getting it dry enough for the work to be done with it in the clean room.

 

[BigInch]

OK I don't have any experience at clean room work, but from what I do know about it I can tell you with complete certainty that it IS a totally different ball game. I think the problem might be that your working with a "friendly" and he hasn't any experience. Actually that is the REAL problem. Why on Earth are you working with a contractor that has no experience doing his job. It's usually bad enough for the engineer and contractor to be on the same team anyway, but being you both have no experience at the job you're trying to accomplish, seems like a recipe for total disaster. He's asking why and you don't have a clue. How you gonna get this thing built seeking daily advice on the internet? Somebody's got to find some experience somewhere ... very soon. In the meantime, it's probably not a good idea to run around questioning Sandia, as they are the only ones you've found so far with any experience at all. What say you just follow Sandia's lead, until somebody else with a ton and a half of experience in clean room works checks in here. Sorry, but that's the best advice I can give you.

 

[PEDARRIN2]

I totally agree with your statement and I gave you a star for agreeing with what I feel about the mess.

I don't like the design build philosophy because it, in my opinion, comprimises the design to maintain a construction cost the contractor has given. I always have to check with the contractor to see if what I am designing is within his bid budget.

The contractor I alluded to is a subcontractor the mechanical contractor has brought in to do this work since he isn't qualified for the work himself. The subcontractor has worked with electropolished stainless steel of the same quality as the specification. He has worked with gases much more agressive and sensitive as nitrogen - but has never run into the flushing requirement in the field.

In my opinion, my company is not really qualified to do this - but we are doing this project. We are also researching other engineers/companies, who are qualified to review the spec to help us to understand what is involved and where, if anywhere, the spec can be edited. We are also looking in a lot of other arenas for assistance. This was just one I was pursuing.

I have advised the same thing as your last statement - follow the spec unless somebody who has actually done it tells us different.

We'll see where it goes.

Thanks for the to the point comments.

 

[BigInch]

I wish I could have given you some better advice, what I said being pretty much obvious, but sometimes the obvious is the most difficult thing to keep your faith in, especially when you can't see the forest for the trees and athe obvious is being questioned by an impetuous contractor!!! OK, so you're the engineer and you're stuck with what you're stuck with, so just make anybody that wants to do anything contrary to what you have learned so far prove it until your damned, well and good satisfied. Otherwise stick to what you've learned so far.

 

[vpl]

It might be worth checking in with Sandia Labs. It might take a few tries to get to the right person, but the nice thing about government organizations is that they take the "serving the public" fairly seriously.

Patricia Lougheed

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[BigInch]

Patricia, star 4U because your advice was even better than mine.