WorldWide Drilling Resource

Terms Part 12 by Bill Corey Pentair Water Training Institute So we talked about how to use the friction loss chart last month, and I men- tioned we would look at the chart on fit- tings. In the friction loss chart, there is a multiplier used to tell how many feet of head you will lose per 100 feet of pipe. It is not the same when you talk about fit- tings. With fittings, what you do is convert the fitting, say an elbow, into a straight piece of pipe. The chart on this page shows how long the elbow would be if it were straight pipe. We use this chart in our professional condensed catalog. As you can see, it is very limited, but it does give you steel, cop- per, and plastic. Note the plastic men- tioned here is Schedule 40 Ridge PVC. The reason I’m pointing this out is because steel pipe and Schedule 40 PVC have the same ID (inside diame- ter), which means the velocity in each of these pipes will be so close to the same we would not be able to tell the differ- ence. You will also note, if you look at the 90° standard elbow 1¼-inch, the copper and steel pipe has the same amount of straight pipe, four feet. But when you look at the plastic pipe, it has a straight factor of seven inches. Now we al l saw last month that plastic pipe had about half the friction loss of steel pipe, so why would the steel elbow have less straight pipe than the plastic elbow? The answer is the way the pipe is made. If you look at the steel or copper elbow, because the next piece of pipe goes inside the elbow, it means the elbow has to be larger on the exit than the entrance. When, however, you look at the plastic pipe, the entrance and exit are the same size; and for that matter, the elbow is the same size all the way through it. This, of course, will increase the velocity of the water and make the elbow count as a longer pipe. We have an engineering manual with many more fittings, but all in steel. If you would like this in an Excel file, please contact me, and I will see that you get a copy. It has several fittings and pipe sizes up to 48 inches for steel and 12 inches for both Schedule 40 PVC and Schedule 80 PVC. It even has smooth bore hose to 8 inches and there is a pipe size chart with the ID of all pipe starting with 1/8-inch, going to 48 inch- es. I’ve added color to the charts to 89 WorldWide Drilling Resource ® DECEMBER 2014 make it easier to determine which pipe should be used with which flow. Have a wonderful holiday, and see you all next month. Bill michele@ worldwidedrillingresource.com