Monday, April 8, 2013

Sucking Through a Coffee Stirrer

Have you ever tried using a coffee stirrer as a straw? I have attempted to use a coffee stirrer as a straw when I was really thirsty, needed a straw, and none were available. After all, they do look like a straw: they have a small hole running up the middle. In fact, you can get a little bit through, but the process is slow and frustrating. The restriction created by the small hole in the coffee stirrer just will not allow very much through. When you connect your vacuum pump up through standard 1/4” hoses, leaving the Schrader cores in the Schrader valves, you are essentially forcing your vacuum pump to draw through a coffee stirrer. It’s not impossible, but very slow and frustrating. The restriction imposed by the Schrader valve and small diameter hoses restrict how much gas can come through, slowing the process down. You can dramatically reduce the time it takes them to evacuate a system by removing these restrictions. In fact, removing the restrictions will do far more than getting a bigger vacuum pump. The same pump you already own can probably evacuate systems in half the time you are accustomed to by simply removing the restrictions (assuming you keep the pump clean and change the oil). The biggest restrictions are the Schrader valve cores. You can buy two vacuum rated core removal tools and dramatically reduce your evacuation time, even using the same hoses and gauges  (so long as they don’t leak). The core removal tools allow you to remove the core, evacuate the system, charge the system, and then replace the cores. Next, you might want to use 3/8” or even 1/2” hoses to evacuate rather than 1/4” hoses that came on your charging manifold. That replaces the coffee stirrer with a properly sized straw. Finally, you should consider using a manifold with a larger bore. Any one of these improvements will make a noticeable difference; all together, the effect is close to amazing. Appion sells a Megaflow Speed kit that packages these three components together. Tru-Tech sells a Rapid Evac Kit that contains the hoses, valve core tools, and some Nylog vacuum sealer. They are both a little expensive compared to standard manifolds or 1/4" hoses, but they work much faster. Just ask yourself this – how much would you pay to cut your evacuation time in half.

If you teach air conditioning, you should contact Appion. They are giving away a vacuum pump to schools that purchase one of their Megaflow Speed Kits. While you are at it, ask for one of their recovery machines too. Note: this deal is just for schools – they are not giving away a recovery machine and vacuum pump with every gauge set sold. E-mail and ask for details on their educational program.

Warning: After you use better equipment you won’t want to return to your old coffee stirrers.

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