Slack must be left in a flexible hose during installation because, when under pressure, it

Slack must be left in a flexible hose during installation because, when under pressure, it

• A. Expands in length and diameter
• B. Expands in length and contracts in diameter
• C. Contracts in length and expands in diameter
• D. Contracts in length and diameter

Answer: (A)

When a flexible hose is pressurized, the internal pressure pushes outward on the wall and also along the length of the hose. This creates hoop (around the circumference) stresses and axial (along the length) stresses in the hose material. As a result, the hose tends to bulge outward (its diameter increases) and also elongate slightly (the length increases). Leaving slack during installation gives the hose room to expand once the system is pressurized, preventing it from pulling tight, kinking, or overstressing fittings. So both length and diameter expand under pressure, which is why the idea that it expands in length and diameter is the correct way to think about it.

When a flexible hose is pressurized, the internal pressure pushes outward on the wall and also along the length of the hose. This creates hoop (around the circumference) stresses and axial (along the length) stresses in the hose material. As a result, the hose tends to bulge outward (its diameter increases) and also elongate slightly (the length increases). Leaving slack during installation gives the hose room to expand once the system is pressurized, preventing it from pulling tight, kinking, or overstressing fittings. So both length and diameter expand under pressure, which is why the idea that it expands in length and diameter is the correct way to think about it.