Vacuum Relief Valves

To save wear and tear on pumps, relieving vacuum during idle time is a good idea. May 15, 2012

Question
Does anyone have a source for reasonable priced pneumatic or electric vacuum valves? My rover 30 shuts the vac flow completely off to my Becker pump when not running. It heats up the pump and runs it hard unnecessarily. I just need something I can have open up when others are closed to release the pump. I am also considering adding another pump so I may need valves to engage the second pump.

Forum Responses
(CNC Forum)
From contributor M:
Try Rankin Industries; they may have direct replacement OEM units at about 1/2 the cost from the factory. I used to buy all my Pneumax and Univer valves from them.



From contributor C:
Why don't you add a relief valve? Your pump would simply overcome spring tension, open the valve, and allow enough air through to keep your pump cool. Plus you would not have to worry about flipping a switch or being electrically/pneumatically dependent. Check with Republic Blower - they have relief valves that can be adjusted to the pressure you want it to open.


From the original questioner:
You may or may not know that the Becker has a built in relief valve. It is set at about 21" of mercury. The function of the relief valve is to let in the bare minimum of air as to not let the pump overheat. This has the pump working at its highest level and highest heat possible. Also other than start-up, itís at the highest current draw and this is going on as no work is being performed. There would be a great savings in wear, heat, and electrical draw if you can open the inlet to free flow air when not in use. Becker does not recommend turning the pump off and on as it is hard on the vanes.


From contributor D:
That's the first time I've heard not to turn the pump on and off. I've been doing this for years and had exactly the opposite results. The first couple years the pump ran all day, every day. I got pretty efficient with the vane rebuild kit after the second time. However, six-seven years later with judicious use of the pump only when actually needing it, I've not noticed any premature wear. These pumps get scary hot only after running for 20 minutes. I might be wrong, but I just think Becker wouldn't mind selling more new vanes and pumps.


From the original questioner:
Becker mentions that turning the pump on and off a lot lead to chipping of the blades, not wear per say. If you have rebuilt the pumps then you know how they slam to the outside with centrifugal force when turned on. At $1200 for a set of vanes I don't like the risk, the heat, or the wasted electricity.

Now back to the original question. Does anyone know where to purchase vacuum valves at a reasonably price? How about a high price source, any source?



From contributor C:
Try Valterra, they may have a pneumatic gate valve up to 4" that you can use to provide that added airflow. I have used those kinds of valves to isolate tables before, and it should work for your application.