I would like to know this if I put a pump at point a near my well shed that has 25 psi output rating and a vacuum pump with the same rating 100 feet higher up the hill will I get water up the hill at a 75 degree angle . It would cost too much to go around and power is limited and must be split. No way to put a pump midway It has to be this way. The vacuum pump on top can be bigger.

Our go-to pump expert will be along shortly but I'm wondering why you control box is set at 25 PSI. Is that all the pressure it will produce? More details please, TTom

In theory the greatest amount of height that a vacuum pump can lift water is about 32 feet (amount of water head equal to 1 atmosphere). Actually in practice it's somewhat less than that - perhaps 20-25 feet due to losses along the pipe. If the output of the first pump is 25 psi, or about 1.8 atmospheres, it can push water uphill about 32ft x 1.8 = 56 feet. So the maximum amount of elevation change you can get with this arrangement is about 75-80 feet. You say the hill is 100 feet - is that it's height, or the distance along the slope? You should consider installing a more powerful pump at the well head to push water up the hill.

I'm like Speedball. Why is the first pump limited to only 25 psi?

How far from water is the pump? Is this pulling from a well or from a stream/lake? I'm thinking you could go with a sub pump if possible and just pump it to the top.

Might add that even if the pump/vacuum pump could get it to the top of the 100 foot climb, you still have what would be a trickle of water with very little pressure. In other words, not very usable.

BTW, nice math work ebaines. I figure it this way. One psi will raise a column of water about 2.3 feet. So 25 times 2.3 would be 57.5. That's an approximate figure. Your 56 feet is no doubt much closer to the truth, but one way or the other, it won't get the water close enough for the vacuum pump to help out.