Gracol contracted to FDI to produce FRP pipwork for the drainage system for the second trailrace tunnel:
This required 6, 800 diameter pump pipes and 4, 600 diameter drainage pipes. This pipework was tested to meet tequired standard for 30 bar pressure and certified for 100 years opperation in underwater conditions:
Photos show (testing of pipework) assembley of final shape with stainless steel ring flange backing plate and centre ring band to lock pipe into concrete retaining wall. Loading the truck was also quite an effort. Final installation shows the pump side with sealed pipe end. The pumps are not connected until dewatering is required for tunnel maintenance.
Installation of pipework
These are examples of GRACOLITE flanges and elbows..
