Well, will the corrosion and wear you are trying to prevent for "two years" be on the inside of the temporary pipe, or the outside?
Continuous immersion, or air + salt water tides, or air + salt spray, or air + waves and impact?
What is the fluid inside the pipe? What pressure and temperature?
When the "paint" goes bad in less than 2 years, what is the penalty when the pipe corrodes through? Oil spill? Fire, flooding, feasts or famine?