Is having 2 vacuum pumps twice the vacuum

[halladaymaple]

Hi all:

I have 2 Delaval 73 vacuum pumps. The first one is in service and the second is a spare (everyone should have a spare) My question is.... What would happen if I install both vacuum pumps on the same line? The both have the same motors on them as well. Would it get to MAX VAC faster ? would it increase my MAX VAC, would it overcome leaks that occur? would it be a waste of time.... I am going to plumb it up this spring and see, but if anyone has tried this before I would like to hear what happened.

Thanks
DH

[spud]

Your electric bill is going to be twice as much.:lol: Two pumps will have more CFMs but it might not matter depending on the size of your mainlines. I would just save the other as a back up.

Spud

[BreezyHill]

DH, you will have more CFM on to the system.
Yes, you will bring the system to your max reading faster than running one pump.
No, two pumps will not increase your max inches of Hg reading.
It will over come leaks up to the cfm ability of the pumps and then your reading will drop.

A spare pump plumbed in is a great idea. Last two seasons I have run a D 73 and a D 75. &5 is the main unit and 73 was the spare. the 73 actually runs higher vac readings than does the 75. 75 maxes out at or near 27 and the 73 goes to 29 plus a needle. Last season I stopped running the 75 except for startup in the morning or if there was a leak. The last week of season I had some tubing failing that was 3-4 seasons old and ran both to keep up with the leaks best I could.

Mine are upstairs above the releaser and are connected to a 3" tee on a 3" pvc that goes down stairs to the releaser. I run an oil reclaimer on both and refill the reservoir on the 73 by hand. These are great sap pumps since they have metal veins that cool with drip oil very well. I use a fan on the 73 mostly for cooling. Temp control trns fan on at 180 and off at 175. Just a box fan and it does great.
The pumps:
12207
This was a bad day...the 75 spun a shaft and I had to weld the rotor to the shaft after realigning the oiler ports for the veins. It waited til sap stopped running.

The releaser:
12208

Good Luck!

Ben

[mellondome]

If you plumb both of them into the system, put gate valves between the vac and where you join them. That way you can posatively shut either one off without affecting the other.

[BreezyHill]

MD is right, a ball valve for isolation of the pump is a good design addition. The 73 on the left has a isolation valve and you must use a swing check valve to prevent oil from going to the water trap. They to will isolate in the event of a pump failure but a ball valve is nice to check each pumps affect on the system.

Ben

[halladaymaple]

Thanks Breezy Hill for the PIX. I will add shut offs to each. I plan on only using one 73 at a time, just nice to cut over quickly in case.

What Horse power are your pumps you run with the 73 and what RPM?

220 or 120 V

Thanks again


DArrell

[BreezyHill]

120 volt on the 73 and the 75 is 220 the 73 is 3/4hp and the 75 is a 2 hp and the rpm is just under the max on the pump tag. I can check if you need exact speed.