The vertical loop, vented at the top, presents a constant head situation to the pump. The vent at the top can just be an upended tee. Grit pumps are normally open or recessed impellor pumps. and they work best if there is some minimum head available.
Steve
I have designed sewerage pumping facilities, and constructed and installed pump/level systems for 40+ years. Everything but the pump POWER cables cables should be intrinsically safe.Cable seals are a pain both to install and to deal with during maintenance. IS barriers and downstream wiring...
Sorry about being so late. With vacuum "ejectors" it is not unusual to see 3 to 5 times the input pressure as the output. Be conservative about headloss in small piping, sometimes there are many more fittings that you expect. I have used mostly turbine pumps if I felt the calcs were trustworthy...
I see on sheet 96 of 336 (the mixed up plan sets) shows three area drains (referred to as “DD”, Deck Drains?) are indicated in the sloped area surrounding the pool. And the pool is a simple rectangle, no stairs shown. But on later sheets the drains don’t show. The 2018 report indicates that the...
I worked on an existing 4500 PVC foot sewer force main laid parallel (in the same trench) to a gravity sewer line. Very low pressure at the pump discharge. The line design (Plans) showed fittings around the gravity manholes. Very low pressure at the pump discharge. Failures were monthly, some...
I have seen sunlight damaged PVC above the water line, and have always used metallic (preferably SS) until about 12-inches below the water level. For EQ tanks that are sometimes empty I used all SS.
Steve
The thread form is completely different. The thread form of a M20 bar is straight and Metric dimensioned while the FNPT is tapered and NPT threads are inch. As to diameters, well M20 is M20 while NPT, or pipe diameters, are wildly different.
Steve
Assuming that both ends are underwater and the apex of the syphon is not higher than about 23-25 feet above the source, put a line size tee with the side outlet facing upward at the high point, add about 1-foot of pipe with a cap. At the very top, connect a 3/8 or ½-inch hose leading to a small...
With the second pump 100 feet higher than the first, and the check after the second, the pipe connecting the first to the second will contain a high vacuum. Two things come to mind, first, the need for a 2-3 inch vacuum/air valve prior to the second pump so as not to expose the pump body to a...
Do not fall into the trap of locating the second pump to far up the gradient, it should be well below, so that the first pump sees a lot of inlet pressure. I have started the low pump first and then after 5-10 sec., started the second. I have seen it done many ways, but I have only used one...
Weird timing, as of 4:30 last evening I was handed a G-R drawing of two submersibles in series (two sets actually).They are sewage, 100 GPM at 95’ each pump or 100 GPM at 190’ per set. They are across the line starting, with one wet and one dry. They have been installed for 14 years and we have...
The title suggests a “combination” air valve. These typically have a large float and a large vent, with the float rising (or falling) with water level. BUT, the large float may seal the large orifice and say there if air accumulates and the pressure is constant or higher. It is held shut by...
If you are working with Gray Cast made in the 1960’s it will be the same OD as todays AWWA specified Ductile Cast. If you were working with cast pipe made in the 1920’s then you may have pipe cast in a sand mold. For this you would measure the circumference and calculate the OD. You would then...
