Rigging, Hangers, and Supports Flashcards

When inspecting a wire rope sling before a lift, which defect requires the sling to be immediately removed from service?

Answer: Six randomly distributed broken wires in one rope lay

Six or more randomly distributed broken wires in one rope lay is a disqualifying defect per ASME B30.9.

A spring hanger is used instead of a rigid support when:

Answer: Thermal expansion causes the pipe to move vertically during operation

Spring hangers accommodate vertical pipe movement caused by thermal expansion while maintaining a controlled load.

What is the purpose of a pipe anchor (fixed point) in a piping system?

Answer: To prevent all movement and absorb forces at a specific location

An anchor restrains the pipe against all movement and absorbs thermal, pressure, and dynamic forces at that point.

Which rigging configuration provides the greatest mechanical advantage when using a block and tackle system?

Answer: Four-part line (double block and tackle)

A four-part line doubles the mechanical advantage compared to a two-part line, allowing a lighter applied force to lift heavier loads.

What does the term 'SWL' stamped on rigging hardware indicate?

Answer: Safe Working Load

SWL (Safe Working Load) is the maximum load a piece of rigging hardware is rated to carry under normal working conditions.

A constant-effort (constant-support) hanger maintains a consistent load on the pipe by using:

Answer: A counterbalance mechanism that keeps force constant throughout travel

Constant-effort hangers use a cam-and-spring or counterweight mechanism to maintain a nearly constant supporting force regardless of pipe position.

When a load is suspended from two sling legs at a 60° angle from horizontal, the tension in each leg compared to a vertical single-leg lift of the same load is:

Answer: Greater than the load weight

As the sling angle decreases below 90° from horizontal, the tension in each leg increases beyond the simple load weight due to the horizontal force component.