Holdfast Training Services Trial Blog

To Mark/Jim and others who are interested

At the moment I am working on a design check of a liquid nitrogen cryogenic system.

The exact questions / issues that I am looking into are:

1. Standards / Regulations / design guidance as to the materials to be used for the liquid nitrogen line and the cyrovent line.

2. Standards/Regulations for frequency for Cryovent cut ins on Liquid Nitrogen Line

3. Standards / regulations of venting liquid nitrogen boiloff

 I have looked at ASHRAE refrigeration guide Chap 47, but this does not seem to have the answers I need. the others around me aren’t sure where else to go.

THe Sub-contractor who is installing the system seems sure of themselves and is stating the original design was inadequate and it should be installed the way they are doing it (which oddly costs more).

(Definition of Cryovent – a port that allows the boiled off nitrogen to escape.)

In brief

I have been finishing off various items within the handover of the Steam Sterilization Plant, and starting to get more stuck into more aspects of the main USAMRIID project

Key Interesting points

Snagging and deficiencies lists within SSP.

We have generated a comprehensive snagging list for the SSP, and the discussion about what is exactly stated in the specification has ensued. It is interesting that despite the fact that no 5% retention is held no one is concerned that the contractor will not make good his mistakes, this is due to the power that the federal government (Us) has to command them to work, and the fact that it is essential for the contractor to stay onside with the Corp of Engineers for continuing work.

Testing of PALL filters.

In order to filter the high pressure steam the other gaseous waste from the SSP, HEPA filters are used to clean the air. These operate at high pressure and high flow rates. The testing of these filters has taken 3 weeks, due to the complex nature of the filter skids, and the fact that the method of testing has had to be changed several times to find a test that will allow the filters to pass. We have had to ensure ourselves then reassure the client that the “easier to pass” tests do give the same level of assurance and will be repeatable within their operation and maintenance schedule.

Investigating “Leak in system”

Within the SSP all non expected liquid waste is drained down to the basement, from where it is pneumatically lifted to the storage tanks on the top floor, ready for processing with the other effluent. The receiver/ejectors in the basement have been firing more than would be expected, and so I have been researching to try and find a plausible source of the water, as we were concerned that it might be a symptom a larger problem.  Having isolated an onsite Auto-Clave this appears to have prevented the consistent leak, and so this more easily fixed than we had feared.

Design Alteration to the SSP

As mentioned in previous Blogs a design fault has been recognized, and is in the process of being corrected. In the meantime most of the other work has been finished to the original timeline, and so is nearing completion. A difficulty has arisen in so far as the contractor wants to know whether they are to hand over the building now as originally agreed in the contract and the original design, or continue maintenance of the facility for a few months until the design change is finalized and complete, and so they can hand over a fully working facility. Clearly either of these two options causes costs, and have their own advantages and disadvantages. Trying to extract these costs from the design contractor is apparently unlikely to succeed due to the contract style employed by the Corp of Engineers and federal Government.

USAMRIID

Duct Testing

Conducting and signing off the pressure tests of the installed air ducts – ensuring that they are adequately air tight,

Coating Application

Due to the higher heat and humidity than would be seasonably be expected it is causing some concern for the application of coatings. These are quite sensitive to atmospheric conditions, and it has been agreed in the contract that within selected high containment (high value)  areas they will be monitored, this has worked for these selected areas, however the non monitored areas are noticeably less controlled and a lower quality of finish is achieved.

It has been decided that the cheapest and easiest way would be for the Corp to monitor all the others areas with HOBO data loggers, and then provide this information to the contractors. This is another example of the Corp assisting the Contractor more than might be usual, and so at least from our side the partnership relationship seems to be going well!

Partnering

Having observed different members of the contractor and Corp interact it has become clear that the “partnering” spirit is mostly more visible in the Corp (probably due to the more relaxed approach to budgets), and also very highly personality dependant. It appears that the Latham report has not been fully read and digested by the older members of the contractors. Partnering with someone who does not want to reciprocate seems in some ways to be worse than both being adversarial, and both playing the same game.

Lack of Shop Drawings

In some of the areas of the USAMRIID project the Corp have allowed the contractor some flexibility of the detailing, in order to allow them to find the most cost effective solution at the time of construction. This is now causing some difficulties as the contractor is now unable or unwilling to provide shop drawings, and so signing them off as an acceptable method is difficult, as are inspections. This is leading to some disputes where the contractor is stating that our lack of movement on the inspections is delaying them, but we are in turn waiting for the shop drawings in order to do the inspections. They seem to be obstinately not listening!

Valve Access

Due to the high density of services within the USAMRIID there are many places where it is difficult to get to the commissioning and isolation valves of the mechanical system because other systems have since been placed in the way. This is clearly unacceptable and will also be very costly to correct, due to the number of places where it has occurred. This does seem to be an elementary error, that should really have been stopped before it got this far, however the number of services will make any solution difficult to implement. I am considering suggesting the use of highly trained monkeys for the O&M crew, as they will be smaller and also able to climb on the ducts.

What have I learnt?

Valve access

As early as possible in the design process the maintenance of the plant must be considered, otherwise it is doomed to fail. Within this project it would probably have led to even more services floors, and a higher price-tag so would have been inevitable. A full 3D services plan would have helped for the visualization of services clashes.

Testing and Commissioning

Do not underestimate the time and budget required for the testing and commissioning, especially on complex projects. Problems will be found, this is the point of the process. Ensure there is a plan in place for making larger and time consuming alterations.

Coating Application

The sheer act of monitoring will increase the level of workmanship, as long as it is done across the board and against clear and relevant criteria.

Partnering

Can be effective, yet the stick is also still required at times. Try to imbue a partnering attitude from as early on as possible, and work hard to maintain this.