Interior lining of steel penstock

I am not from the related field and still taking the liberty to reason it out. My reply may be off topic. A higher thickness pipe / plate would always exposed to corrosive as well as abrasive water quality (even after one layer is taken away). When a coating is provided, it has special adhesive, anti corrosive and anti abrasive property. The life of this coating and therefore the life of pipe plate would pay more than the cost of extra thick pipe / plate. Overall life span would also play an important role.

Depending on the depth of your pockets, and the anticipated water pressure, you might wish to cinsider some type of Tetra-Flouro-Ethylene material (Teflon comes to mind). Another thought is Fiberglass with an Aramid lining for ballistic resistance. Due consideration should be given to joint design because TFE doesn't like elevated temperaturs, found in welding. Neither does Fiberglass; although, with sea-water cooling, we have used Fiberglass for exhaust pipe on boats.

Teflon coating has been recommended by hydro generating unit manufacturers, but its performance is not proven. I have seen damages to turbine and penstocks due to cavitation and silt, where the damage was enormous and had to undergo massive renovation works. In one case, the turbine was beyond repair and had to be replaced. I haven't come accross fiberglass protection. Have they been used in penstock where the velocity of flow can go upto 35ft/ sec? Please let me know where they have been used and how is its performance

Thanks!

Samuel Chelliah

Hello everybody:

I give a lot of thanks to all for the comments.

Dear Samuel, I will be waiting for that information.