A Plenum Holiday

Cooke Vacuum wishes all our friends a big fat plenum for the new year.   Ok, a weak wordplay, the antonym of vacuum,  but a nice word, barely-used and low mileage.

What do we hope for in the coming months?   A lot less war,  first and foremost.  A lot less religion applied as a weapon.   Much more attention to improving the lot of man on the planet.   A return to the vital role of science and technology in solving the problems of science and technology.    Restoration of faith in society,  government,  civilization.

Much more specifically,  we hope that your kids can find careers like yours,  have valid reasons for exploring the wonder of the physical world,  touch,  measure, design, invent and create.   Even get their hands dirty.   We hope that national funding for science catches up with the reality of a global economy.   We hope that curiosity and altruism edge out placidity and greed.   We hope that the work that we do pleases us,  and helps others.   And at Cooke, we hope that you continue to challenge us  to build the furniture of understanding.

Best wishes, now and always,

Richard and everyone

Energy Savings and High Vacuum

We make diffusion pumps – an antique but robust and effective route to high vacuum, especially in little and very large systems. Between the diff pump and a cryotrap, there’s a great deal of energy expended. A 20″ pump may use 15kW, with nearly all that power going into the cooling water, which is another story, since almost everybody is forced to use chillers. Cryo pumps also use a great deal of power, and, like diff pumps, can’t be turned on very quickly, so they’re generally left on all the time. They need a recirculating chiller to function as well. (Or, if air-cooled, the same burden thrown on the building’s HVAC – murderously expensive in clean rooms.) Turbomolecular pumps ramp up quickly, and use tens of watts instead of thousands, but in many applications, either cost or chemical considerations rule these out. Then, there’s liquid nitrogen, an increasingly expensive cryo trap filler.

For some applications, such as semiconductor fab or heat treating furnaces, there’s almost no choice: you use whatever technology is traditional and is known to work, regardless of energy consumption. For others, such as

And The Question is….Aluminum

And the answer is, sure, use aluminum. It’s light, chemically a better bet than stainless, a great vacuum material. So, other than major semiconductor tools hogged out of a solid, steamer trunk-sized billet of very clean forged aluminum, why all this stainless? One reason: flanges. Metal-sealing (CF) flanges are rather complex as aluminum/hard material hybrids- can you say ‘explosive bonded’? Nearly all of the flanges, fittings, adapters, feedthroughs etc. are available only in stainless, and you just can’t weld them to aluminum chambers, so generally, the chambers tend to be stainless. Parts that don’t have to weld on, such as doors, are easy with aluminum. Welding aluminum is sometimes thought to be tricky… and it is, especially if a join has to be reworked, and maintaining tight dimensional tolerances without careful and complete fixturing can be impossible.

If you do choose to design the light stuff into a vacuum project, then, do the following:

Blog along with us

A new owner of an older Cooke system writes asking about “blogging along” with us to learn the mysterious art of system rebuild. This is not as outrageous or naive as it sounds. Because we have thousands of systems out there, and because many of them are owned second-, third- or more-hand, often by people new to high vacuum, there is a need for help in restoring, adapting, or maintaining. My closest competitor charges $3200/day to send a man out – presumably plus travel. Clearly beyond most budgets! We answer many, many telephone or email inquiries, almost always for free; our customers, even if they’re not original purchasers, can’t afford on-site help. But, from a business standpoint, what we do is crazy!

The suggestion from our more businesslike friends is to charge for telephone and written help beyond warranty, something lower than a typical field service rate, but enough to pay for someone to do it. How exactly we can do this remains unclear, especially since few of our (university, especially) customers can easily approve charges by themselves. We certainly don’t want to drive anyone away, but those hour-long conversations about how to tell if a pump has departed, where to buy something we don’t sell, or what to do if an ion gauge doesn’t light up….. they have to addressed a little better. Open-ended PO’s? Charge card numbers? Anyone who can offer suggestions — blog us!