Most prime movers require careful coupling alignment at or above what SFM?

The correct answer reflects the critical nature of precise coupling alignment for prime movers, especially as their speed increases. At or above 3,600 surface feet per minute (SFM), the dynamic effects of vibration, thermal expansion, and potential misalignment can lead to significant and detrimental impacts on system performance and longevity.

When machinery operates at high speeds, such as those at or exceeding 3,600 SFM, any misalignment can cause increased wear, vibration issues, and potentially failure of components. Thus, meticulous alignment becomes crucial to ensure smooth operation and to minimize mechanical stress on the system.

Machines operating below this threshold may still require proper alignment, but the implications of misalignment are less severe compared to higher speeds, where the forces involved can exacerbate the issues. Properly aligning couplings and ensuring they are within specified tolerances is essential for the efficiency and reliability of the machinery involved.