Steel pipes in water supply: Which statement is the most accurate and generally applicable for design selection and specification?

Introduction / Context:
Choosing pipe materials involves pressure ratings, jointing, corrosion resistance, installation method, and life-cycle cost. Steel is a common choice for high-pressure mains and long river crossings because of its strength and weldability.

Given Data / Assumptions:

• General municipal water transmission context.
• No special linings/coatings assumed unless stated.
• Buried versus above-ground lines impose different thermal and corrosion considerations.

Concept / Approach:

Steel’s high tensile strength and ductility allow economical design at higher internal pressures and for special conditions (e.g., surge, seismic restraints). However, jointing, thermal movements, and corrosion protection must be managed through welding/flanging, anchors/expansion loops, and linings/coatings/cathodic protection.

Step-by-Step Solution:

Verification / Alternative check:

Design manuals specify steel for high-pressure transmission and surge-prone systems, confirming its pressure suitability. Modern practice favors welded/flanged joints, not riveted joints.

Why Other Options Are Wrong:

• Riveted-only joints: obsolete in modern practice.
• No expansion provisions: false for exposed lines; buried lines see less thermal swing.
• 100-year life without protection: unrealistic; coatings/cathodic protection are needed.
• Unsuitable for buried service: incorrect; steel is widely used when protected.

Common Pitfalls:

• Ignoring corrosion control in steel pipe design.
• Assuming thermal issues are identical for buried and above-ground lines.

Final Answer:

Steel pipes are suitable for withstanding high internal pressure.