ITMC Pneumatic Systems 4

Question 1

In a meter-out flow control configuration, the restrictor is placed:

Accepted Answer

On the exhaust side of the actuator port

Answer

Meter-out restricts exhaust flow leaving the cylinder port, providing smoother speed control especially under varying loads.

Question 2

A pneumatic system operates at 90 PSI. A cylinder with a 3-inch bore extends against a 500 lb load. What force does the cylinder generate? (π ≈ 3.14)

Accepted Answer

Approximately 636 lbs

Answer

Force = Pressure × Area = 90 PSI × (π/4 × 3²) = 90 × 7.07 ≈ 636 lbs, which exceeds the load so the cylinder will extend.

Question 3

What is the purpose of a pilot-operated check valve in a pneumatic holding circuit?

Accepted Answer

To lock an actuator in position and release it only when pilot pressure is applied

Answer

A pilot-operated check valve blocks flow in both directions until a pilot signal unlocks it, allowing a cylinder to be held firmly in position.

Question 4

Compressor oil carryover into the air distribution system is MOST damaging to which component?

Accepted Answer

Rubber and polyurethane seals and tubing

Answer

Petroleum-based compressor oil degrades rubber and polyurethane seals and tubing, causing swelling, softening, and eventual failure.

Question 5

Which diagnostic tool is MOST effective for locating pneumatic system leaks?

Accepted Answer

Ultrasonic leak detector

Answer

Ultrasonic detectors sense the high-frequency sound generated by air escaping through leaks, allowing precise location even in noisy environments.

(ITMC) Industrial Technology Maintenance Certification Practice Test