Its been an interesting few weeks with the Snowdon hydro. The flange coupler (the bit which joins the plastic pipe to the ductile iron pipe) has let go… a little bit. We had known a month or so ago that it needed changing as the team at the farm has seen a leak in the pipe. When the section was dug out the coupler in question had slipped some 4cm off the ductile iron pipe. We had a problem! Luckily the monsoon season or back to back storms had just finished which allowed us to dig up a section of the pipe in order to replace the faulty coupler. This second coupler was installed and leaked immediately…but the third coupler. you guessed it! This has held.
In our mopping up and evaluation of the project all of us have agreed that we would install MDPE plastic pipe all the way next time. The Ductile was half the price for the lower 200m section butthis type of pipe has been a lot less forgiving in terms of its ability to bend and adapt to the terrain. Trenches have been deeper and angles have had to be more gradual. We would have still needed the coupler to join the plastic to the steel in the turbine building anchor block but that would be off the mountain and ‘probably’ easier to manage…juries still out on that one. If this is the worst thing we have on the whole project I consider it a minuscule problem considering we have a potential 100 years of life. It has been annoying rather than a big problem…normal service has resumed!