Industrial Piping Support Systems and Classifications

Detailed Analysis of Piping Support Systems

This document explains different piping supports in detail.

Classification Based on Function and Rigidity

Rigid Supports

These supports provide completely stiff resistance, preventing movement in specific directions. They do not allow for thermal expansion.

• Anchor (Fixed Support): Restrains the pipe in all six degrees of freedom (three translational, three rotational). It completely locks the pipe in place.
• Restraint / Guide: Allows the pipe to slide along its longitudinal axis but restricts lateral (side-to-side) movement.
• Stop / Directional Anchor: Allows movement in some linear directions but blocks it completely in another (e.g., preventing forward axial movement while allowing side movement).

Elastic and Flexible Supports

Used when a pipe undergoes thermal expansion or contraction. They support the weight while allowing the pipe to move vertically.

• Variable Spring Hangers: The supporting force varies with the pipe's deflection. Used when thermal movement is relatively small.
• Constant Spring Hangers: Provide a constant supporting force throughout the entire travel of the pipe. Used for critical, high-temperature lines with large vertical movements to avoid transferring stresses to sensitive equipment like pumps or turbines.

Dynamic Supports

These do not interfere with slow thermal movements but immediately lock up during sudden, rapid movements to protect the piping system.

• Snubbers (Shock Absorbers): Act like hydraulic pistons or mechanical brakes. They absorb sudden loads from earthquakes, water hammer, or safety valve discharges.
• Struts: Rigid rods with spherical bearings at both ends, used to restrain dynamic loads in a single direction.

Classification Based on Construction and Installation

Hanging Supports (Hangers)

The pipe is suspended from an overhead structure (like a ceiling or a steel beam) using rod assemblies, clamps, or springs.

• Best for: Maximizing floor space and handling vertical loads.

Resting Supports (Shoes and Saddles)

The pipe rests directly on a structural beam or concrete foundation from below.

• Pipe Shoe: A metal attachment welded or clamped to the bottom of the pipe. It elevates the pipe above the structural steel, protecting the insulation and allowing the pipe to slide smoothly during thermal expansion.
• Pipe Saddle: A welded reinforcement patch that cradles the pipe, used for large-diameter or thin-walled pipes to prevent local deformation.