How to create a vacum?

[FishDog3]

What do I use to pump out the air inside a sealed pipe through a service valve, I am thinking about making a heat pipe.

[cjtune]

You'll need an industrial vacuum pump -not easy to get and operate...

BTW, how are you going to fill in the freon under vacuum? Won't it eveporate easily?

[LimeyGreg]

You can find vacuum pumps at McMaster-Carr or at any good air conditioning supplier, they aren't cheap, and the higher the vacuum they can pull the more expensive they are. You might try a scrap yard, I picked up one for $80, it's a brute but it sure works well on my vacuum oven.

[Magistrate]

vacuum oven?

[LimeyGreg]

Yes, vacuum oven. I repair flexible endoscopes, when I have the time, as a side job. They contain fiberoptic bundles for both light and vision as well as cables and wires. When a fluid invasion occurs it needs to be removed, not an easy task on a sheathed bundle of umpteen thousand fibers.

The oven runs at a fairly low temperature and the vacuum helps pull the moisture from the bundle as well as reducing it's evaporation point. The vacuum is cycled several times during the process and a final purge is done with helium (hygroscopic). It basically speeds up the drying process and helps minimize the staining that can occur in the image bundle during a lengthy drying period.

It's also useful for de-gassing adhesives and coatings prior to application. Another use is in mould making to remove bubbles from the casting and to accelerate curing.

[PDL]

Now aren't you glad you asked???

Now there is someone who knows his job and LIKEs his job.

Hats off to ya!!

[Kingslayer]

LimeyGreg (Jul 11, 2001 08:43 p.m.):
Yes, vacuum oven. I repair flexible endoscopes, when I have the time, as a side job. They contain fiberoptic bundles for both light and vision as well as cables and wires. When a fluid invasion occurs it needs to be removed, not an easy task on a sheathed bundle of umpteen thousand fibers.

The oven runs at a fairly low temperature and the vacuum helps pull the moisture from the bundle as well as reducing it's evaporation point. The vacuum is cycled several times during the process and a final purge is done with helium (hygroscopic). It basically speeds up the drying process and helps minimize the staining that can occur in the image bundle during a lengthy drying period.

It's also useful for de-gassing adhesives and coatings prior to application. Another use is in mould making to remove bubbles from the casting and to accelerate curing.

Ummm....hehe....ahhhhh...hehe....hehe........He said gas!