Horizontal steel pipe shall be supported at _____ foot intervals for 1 1/4 and smaller and ______ foot for 1 1/2 and larger.

Horizontal steel pipe shall be supported at _____ foot intervals for 1 1/4 and smaller and ______ foot for 1 1/2 and larger.

• A. 6, 10
• B. 8, 12
• C. 10, 14
• D. 4, 8

Answer: (B)

Horizontal pipe acts like a beam spanning between supports. The weight of the pipe, the internal pressure, and gravity cause some sag between each support. Smaller-diameter pipes are less stiff and sag more for a given span, so they need supports more frequently. Larger-diameter pipes are stiffer (they resist bending more), so they can be spaced farther apart without excessive deflection. That’s why the standard practice is to support 1 1/4 inch and smaller at eight-foot intervals, and 1/2 inch and larger at twelve-foot intervals.

Horizontal pipe acts like a beam spanning between supports. The weight of the pipe, the internal pressure, and gravity cause some sag between each support. Smaller-diameter pipes are less stiff and sag more for a given span, so they need supports more frequently. Larger-diameter pipes are stiffer (they resist bending more), so they can be spaced farther apart without excessive deflection. That’s why the standard practice is to support 1 1/4 inch and smaller at eight-foot intervals, and 1/2 inch and larger at twelve-foot intervals.