WorldWide Drilling Resource

Terms Part 8 by Bill Corey Pentair Water Training Institute Flow rate or capacity, we are talk- ing about an amount of water moving past a certain point in a given amount of time. Most of us talk in gallons per minute, but we could also use the phras- es liters per minute or cubic meters per hour . I also like to talk here about velocity of the water. To do so, let’s take a look at a cubic foot. It looks like this: If you were to fill a cubic foot with water, it would hold 7.486 gallons. If you wanted the water to move through a square foot in one second, it would have to move at a velocity of 1 foot per sec- ond (fps). We need to remember velocity can be turned into energy and, of course, energy costs money. So keeping energy costs down means watching how fast the water is moving. Bernoulli taught us 1 cubic foot of water will always take up 1 cubic foot of space. So if we wanted to move this same water through a ½- inch by ½-inch area, it will change how the water moves. It would look like the next illustra- tion (½ foot by ½ foot by 4 feet long). If you wanted the water to move through here in one second, it would now have to move at a velocity of 4 fps. Of course, what we are really looking at here is pipe sizing. The larger the pipe, the less friction loss I will have; the smaller the pipe, the more friction loss I will have because I will have more velocity, and the faster something moves, the more friction there is. So flow rate or capacity are locked hand in hand with velocity. The faster something moves, the more friction loss we will have; and the more of some- thing we try to squeeze into a small area, the more friction loss we will have. This is why we suggest you upsize the pipe on both sides of the pump. But NEVER use larger pipe on the discharge side of the pump - it can be the same as the suction side, but never larger. Next month, let’s talk about some fittings. Bill Bill Corey may be contacted via e-mail at admin@ worldwidedrillingresource.com 67 WorldWide Drilling Resource ® AUGUST 2014