ITMC Mechanical Systems & Equipment Maintenance 4

Question 1

During a routine inspection, a technician finds a roller chain with 3% elongation. The correct action is to:

Accepted Answer

Replace the chain immediately

Answer

A chain elongation of 2-3% or more causes pitch mismatch with sprocket teeth, leading to rapid wear and should be replaced.

Question 2

Which lubrication method delivers a metered, continuous supply of oil directly to rolling element bearings in high-speed applications?

Accepted Answer

Oil mist lubrication

Answer

Oil mist systems atomize oil and deliver it via air pressure to bearings, minimizing churning losses at high speeds.

Question 3

A centrifugal pump installed below the fluid reservoir operating with a positive suction head is called a:

Accepted Answer

Flooded suction installation

Answer

A flooded suction installation has the pump inlet below the fluid level, so gravity feeds the fluid to the pump without priming.

Question 4

When diagnosing a pneumatic cylinder that extends but will not retract, the technician should first check the:

Accepted Answer

Directional control valve for proper shifting

Answer

A 4-way directional control valve that fails to shift will prevent the cylinder from reversing direction.

Question 5

What does the term 'interference fit' mean in the context of shaft and bearing assembly?

Accepted Answer

The shaft is slightly larger than the bore so assembly requires force or heat

Answer

An interference fit means the shaft OD is slightly larger than the bore ID, requiring force or thermal expansion to assemble.

(ITMC) Industrial Technology Maintenance Certification Practice Test