Feedback on pipe bursting to rehabilitate old pipelines?
asked 8 March 2016 asked by Sam (3870 points)
Hi, I have used this technique to refurbish several Ø 100 cast-iron pipes and upsize them with Ø 125 HDPE in the last few years. It's a technique that works quite well and is cost-effective, but the site in question has to be a good fit, i.e., with as few components as possible on the stretch of pipe being replaced (valves, connections...). It should be in a straight line and be made of grey iron (not sure it works on ductile/spheroidal graphite iron). We actually use a pipe-splitting method with cutters or blades to slice the host pipe while an expansion head peels it open and the new HDPE is fed in. (You'll have to condemn the first few meters of the HDPE, which will be banged up during insertion and a PN-16 flange is essential). You have to excavate and remove all clamps, t-fittings, and valves before pipe bursting, which is what makes the operation expensive if you have a lot of connections on your pipe section. If service cannot be interrupted, using this technique means you'll also have to set up a temporary override (often aerial) hooked up to all connections, auxiliary pipes.... Again, this means prepping several work areas and can add to your costs. The upshot is there are several constraints to take into account upstream before choosing this method. Hoping to have shed a bit of light on your question