Horizontal Grouting of Pipeline
To grout inside horizontal PVC casing as annular fill around 220KV cable, solution gel to comprise predominantly bentonite, sand & cement.
Geo-loop grouting system
Model 40x500,trailor mounted and towed by Renault Kerax 380 truck 4WD.
Pumping pressure capability 500psi and/or
Mudslayer 350 Limited Access
Bentonite mixing /batching/pumping unit, self powered mounted on tracks
We envisage 1200ltrs of mixture per 100mtr horizontal pipe with cable pulled through pipeline.
Our mix ratio per 1000 ltrs of water (Est 83mtrs of horiziontal pipe line) is; XXx25kg bags bentonite:XXkg sand & XXkg cement This mix ratio will require confirmation to achieve sustainable gel solution.
Depending on back pressure in pipe ,we can select to pump using our bentonite pumping plant and/or by geo loop grout plant. The latter item has higher pressurised pumping against a pressure head.
Pumping from the bottom up to discharge through a inspection/injection point with levered gate valve which remains open during pumping of grout stage, when grout is visually being pumped to waste, a lever valve is shut down. We anticipate inspection/injection points every 100mtrs,however we may be able to extend the pumping interval from a standing location at one inspection/injection point to achieve consistency of discharge in a number of inspection/injection points . Firstly,8 bags of bentonite to be mixed by centrifugal pumping method through reducing nozzle ,allowing for emptying of 1x25kg bag every 3mins. Bentonite is not suitable for mixing by paddle or colloidal mixing techniques.
Cement & sand to be added at a rate of XXkg & XXkg respectively per 1000ltr of water
1st man responsible to operate plant and mix to correct grout, adjust pumping ratio and take samples.
2nd and/or 3rd man to deliver bentonite bags to mixer pot and remove waste bags to waste skip. Shovel appropriate sand & cement mix with bentonite into mixer pot. Refuel petrol tank. When grout is back to surface or all grout has been pumped to wash out pumping lines ,the valves are to be closed and pipe works disconnected.
Health & Safety
All relevant borehole information is to be on site and reviewed before any operations take place. Full PPE to be worn at all times. All relevant COSHH sheets for cementing procedure should be available on request