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Question:

I am using a jet with 2,100 psi/11 gpm. Recently I have encountered an 8- and 10-inch main with sand. Though it was not blocked up, the residents on the street in the complex complained of a strong sewer smell. The manholes have some sewage accumulation. I was not able to flush out all the sand using a nozzle with three forward and six rear jets. What would be the best nozzle type for my jetter to use? Or is an upgrade in gpm needed? Or both?

Answers:

The 8- and 10-inch pipe might be a bit much for the pressure and flow you have on that machine. If you have a wide spray nozzle with a loop attached to the front of it, you could attach a camera to it and watch what you are jetting and cleaning. It would take a lot of work, but it could be done. You might be able to get a large nozzle drilled to meet your machine’s size.

The psi and gpm of a machine equals a cleaning pressure unit (CPU). I do know one of the manufacturers had a CPU to what size pipe it could clean in a certain amount of time. Manholes are vents, too. They will give off smells from time to time. If you can, try a rain guard in it or silicone it up big-time.

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Is the sand hard and settled, or is it easy to stir up? If the sand is easy to get moving (not hard and settled), and is all on the pipe bottom, and is not plugging the line, then you could work it with a flusher nozzle that has all jets back at a wide angle and none forward. Note that forward jets do nothing for you when you do not need to unplug the line; they just are a waste of precious gpm that could add to the back-jet’s flow for maximum flushing power (and hose-pulling power).

Another thing that can help is to add some weight to the nozzle to keep it down in the sand. You should be using a nozzle extension (10-inch-long Schedule 80 pipe-nipple between the nozzle and the hose) to keep the nozzle from wandering into laterals, and if you weigh down the extension nipple, it will help keep the nozzle down in the sand. Some guys even jet up to the next manhole and then tether a brick or some other weight to the nozzle to help keep it down in the sand and debris as you pull back.

Also, a nozzle with fan-type jets (that fan out the spray like the hand-guns at a self-service car wash) will do better at keeping the sand in suspension as you pull the nozzle back to remove the sand.

But, if it is hard-settled sand, then I’d definitely recommend the Warthog head, which will slowly rotate and dig up the hard stuff so you can flush it out with a nozzle like I just described. Also, your 11 gpm is a bit light for working 8- to 10-inch pipe. It’s not bad — it will just take you a while.