Pump head pressure

tupes · Nov 12, 2014

I'm currently in the process of getting an external pump for my rodi and saltwater water barrels to mix and also pump it to my tank after its mixed. Basically I'm going to have it so I can mix my saltwater then I'm go to have it where I can attach a hose when I ready and it'll pump to the saltwater to my tank. All plumbing will be done with pvc.

My question is about head pressure. When looking at max head of a pump 16' 20' or whatever is it just referring to pumping straight up or is it total length of tubing to pump water. While mixing I only have to pump about 2' when sending water to my tank it Has to go approximately 20' in a hose.

heathd.hd · Nov 12, 2014

Pretty sure that's straight up. There's other ways to calculate horizontal pressure loss.

JBNY · Nov 12, 2014

The simplicity sake you can think of the spec as just referring to pumping straight up, but the tubing, connectors, pipe size ect all have a bearing on what the actual head pressure ends up being.

evolved · Nov 12, 2014

It's a culmination of things. Total head pressure (head loss) is essentially the resistance to work the pump must overcome. The main contributors to head loss are gravity and frictional losses, but components like valves, bends, tees and the like also have a minor contribution.

So the 2' of vertical rise will probably be the biggest contributor for you, but 20' of horizontal run can add up in frictional loss. How much so depends on a few things, but mainly the pipe diameter.

If I'm just to guess a number for you, you probably have 3-5' total head loss.

jservedio · Nov 12, 2014

evolved said:
It's a culmination of things. Total head pressure (head loss) is essentially the resistance to work the pump must overcome. The main contributors to head loss are gravity and frictional losses, but components like valves, bends, tees and the like also have a minor contribution.

So the 2' of vertical rise will probably be the biggest contributor for you, but 20' of horizontal run can add up in frictional loss. How much so depends on a few things, but mainly the pipe diameter.

If I'm just to guess a number for you, you probably have 3-5' total head loss.

Besides vertical, elbows (or any bend) have pretty much the biggest effect on head pressure - the friction from the pipe is pretty negligible when compared to elbows in the system.