Gauge to measure DC Vacuum?

[Rob Will]

Where can I get a couple of wall-mounted manometers to monitor the vac in my DC system?

I also want to put a gauge between the blower and exhaust filters to monitor back pressure. Each gauge would need to hook up with a small vinyl tube etc.

Thanks, Rob

[David Giles]

Dwyer makes an inclined manometer that will provide the pressure differential between two points. Or you can make one with clear plastic tubing and a ruler.

[Victor Stearns]

http://www.dwyer-inst.com/htdocs/pressure/Series2000Price.cfm

Dwyer is the leader for this type of measurement.

[CW McClellan]

I found and bought a couple on the "e" brand new -they come in different pressures to :D cheap

[Rob Will]

http://www.dwyer-inst.com/htdocs/pressure/Series2000Price.cfm

Dwyer is the leader for this type of measurement.

Thanks men.
I wonder what sort of pressure range I should select for these two gauges? (The system is a 7.5 hp belt drive Oneida, 28" cyclone dia.)
I'm not sure what the maximum vac from this unit is.

Gauge 1.) Cyclone Inlet (negative pressure)
Gauge 2.) Filter Inlet (positive pressure)

Maybe Robert Witter will see this and help us out.

Here's a pic of the Dwyer Gauges:


Rob

[David Giles]

Most of the smaller cyclones seem to run 6-10" WG suction pressure (1psig = 27.7 inWG). I'd guess that your bigger unit could run up to 15" WG. But you may just want to measure the pressure drop between two points which would be considerably less. A 0-10" gauge should take care of most your needs.

If you already have the cyclone hooked up, install tubing taps at any two points. Connect flexible tubing between the two points. Fill the tubing with 12" of water in each vertical leg. Start the cyclone. The water level will move in each leg. The difference in water height is the actual pressure drop between the two points in "inches water gauge" or "inches water column".

Now you can buy the right pressure gauge.

[Rob Will]

Most of the smaller cyclones seem to run 6-10" WG suction pressure (1psig = 27.7 inWG). I'd guess that your bigger unit could run up to 15" WG. But you may just want to measure the pressure drop between two points which would be considerably less. A 0-10" gauge should take care of most your needs.

If you already have the cyclone hooked up, install tubing taps at any two points. Connect flexible tubing between the two points. Fill the tubing with 12" of water in each vertical leg. Start the cyclone. The water level will move in each leg. The difference in water height is the actual pressure drop between the two points in "inches water gauge" or "inches water column".

Now you can buy the right pressure gauge.

Makes sense to me David.
Thanks,
Rob

[Matt Meiser]

Grainger sells the Dwyer gauges.

[Rob Will]

Thanks for the tip about the Dwyer gauges on eBay. I snagged a 0-4" WC for the filter plenum back pressure and a 0-15" WC for the main duct vacuum pressure.

With all gates shut tight the system generates about 10" WC.
With one 8" port wide open it holds about 6" WC
With freshly cleaned filters the filter back pressure is at 0.5" WCI purchased two surface mounting plates directly from Dwyer and installed everything in a visible location next to the DC room door.
1/4" Polyethylene tubing is hidden inside the wall and connects the gauges to the filter plenum and to the main suction pipe. Here is a pic of the gauges installed. The system is operating here with one 8" port open. Filter backpressure is on top. Main suction is on the bottom.

Again, thanks for the tip.

Rob

[Steven DeMars]

Are you doing this to determine how much vacuum you are losing due to a clogged filter? Not sure what you are trying to accomplish. If this is the case, I would "think" you would get a more accurate reading looking at vacuum nearest the intake of your blower. :)

[Rob Will]

Are you doing this to determine how much vacuum you are losing due to a clogged filter? Not sure what you are trying to accomplish. If this is the case, I would "think" you would get a more accurate reading looking at vacuum nearest the intake of your blower. :)

Hi Steven,
Yes, I am measuring vacuum near the blower intake. The back pressure gauge is connected to the filter plenum.

Here's the plan: With clean filters and one 8" port wide open, measure the vacuum pressure and filter back pressure. I'm not looking for a specific number just a baseline.

With the same port open and as the filters get dirty we should see the backpressure start to increase and the main suction start to decrease.

Hopefully, experience will show me things like how many gates I can have open and still maintain dust removal. In time, a quick glance at the gauges will tell me if I have too many or too few open and also if the filters are becoming restrictive.

Rob

[Steven DeMars]

:)If you want to really see what is going on, throw a CT across one leg of your power to your blower. The amount of amperage will definitely tell you how you are doing also . . . Might as well cover every angle . .

[Rob Will]

:)If you want to really see what is going on, throw a CT across one leg of your power to your blower. The amount of amperage will definitely tell you how you are doing also . . . Might as well cover every angle . .

Great minds think alike;):D:o. The wall is still open on the back side and the electric panel is only about 3' to the left. The DC is on a dedicated 3-phase circuit. I thought about putting a digital amp gauge on the wall just above the pressure gauges.

That will have to go on the back burner for now ----- I've got Daytona tickets GLOAT GLOAT GLOAT :D

Thanks,
Rob

[Steve Milito]

You could make a manometer out of plastic tubing and colored water like this (http://www.komar.org/faq/manometer/).