Ductile iron pipes encased in a concrete bedding ( 100mm all round the pipe )should be used to minimise any breakage due to sagging.
If possible, allowance to be made to provide a covered trench within the building just in case the pipe needs to be replaced.
Your choice of pipe coupled with the length you are running will probably result in excessive head loss, thus rendering your pumps ineffective - unless of course the discharge is minimal.
For pipes running under vehicular loads, the ground cover is inadequate - you run the risk of having the...
