Question:
Does anyone have a recommendation for a riser to use as a retrofit on concrete tanks? I’ve had a couple of customers request them and I’d like to get into adding them. There isn’t anyone locally selling concrete risers so my only option is plastic. Does anyone make their own concrete risers? If so, what type of concrete do you use?
Answers:
I have had good luck with the Polylok Inc. risers. They have an adapter ring that makes it easy to install on the tanks.
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As a precaster, we offer concrete risers, but they can be hard to handle and most folks don’t want a concrete lid with rebar handles sticking up, especially on new construction. We also offer a product called Ultra-Rib that fits in our 24-inch manholes, can be cut to any length, and has a heavy plastic lid secured with screws. For tanks with odd-size openings, we offer Polylok adapter rings that are ready for either 20- or 24-inch riser rings. Polylok makes its riser rings in 6- and 12-inch lifts that are easily installed. We currently sell the 20-inch, which still allows good access. One drawback using concrete or Polylok risers is not being able to cut them to an exact height.
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The precast tanks in our area have two 21-inch round concrete lids that are beveled. Black ABS culvert can be easily cut to length with a hand saw, placed in the hole, sealed with caulking and the original lid put on top and buried a few inches below grade.
For tanks that aren’t more than 2 feet deep, I prefer precast concrete risers; you can’t beat the price or durability. If the tank is deeper than 2 feet we use a FRALO (Roth Septech Tanks) tank adapter ring, plastic culvert pipe and FRALO lid.
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Our company uses a ribbed 24-inch smooth in-wall pipe that comes in 20-foot lengths at about $15 to $18 per foot. We cut it to fit with a reciprocating or circular saw. We purchase the lid from Hedstrom Plastics. The lids come with a seal and screws. They can be filled with sand and the price is very reasonable. When it is installed, we pour a bag of concrete mix around the bottom to make it watertight. Just make sure you backfill evenly to keep the riser/manhole from sliding out of place.
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I like to use black culvert pipe that’s smooth inside. We use lids that slide on the inside and sit flush with the diameter of the pipe. We also use the square-drive fasteners to secure the lids to the pipe for safety. It keeps curious kids from opening lids. The plastic pipe makes it easier to handle and bring to grade. Concrete risers are either too tall or too short for most applications. We use cast risers, but plastic is a personal preference.
Looking For a Jetter Upgrade
Question:
I’m putting together a new jetting system. The one I currently have does 9 gpm at 3,600 psi. It does a pretty good job, but I thought this time I might go big or get off the porch. So since the price of the pumps and drives rise pretty quickly as you go bigger, I’m wondering what would get me the best bang for my buck. Should I go for more volume, or higher pressure? My current setup is great for 4-inch pipe, but it doesn’t really have the jam for 6-inch or bigger.
Answers:
The trick is in matching the tool at the end to your pump. The orifices need to be sized for the flow of the pump. If you have four orifices that need 6 gpm each, you need more pump (or smaller orifices). You can base your pump on your tool’s needs, or you can make your tool fit your pump, but what is important is that the water leaving the orifices is traveling at least 100 fps and that the tool be as close as possible to what you want to clean.
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I have just been offered a deal on the same pump as I have, which is 9 gpm at 3,600 psi. Instead of buying a bigger one, what would be the downside to using two pumps in tandem? I would have the same pressure with double the volume. I could put a check valve after each pump to keep the flows separate. Any reason why that wouldn’t work?
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What is your water supply? Can you provide them 18 gpm without cavitation? Other than that, no problem.
