How to Setup a Clamp Base

Resting supports (Clamp bases, U-bolts and components for guides and anchors) are the most common pipe supports given their high degree of standardization and ease of installation, specially for pipes that rest on structures and pipe racks.

They can be used as a free sliding support, or as guides and anchor points.

Basic Setup

Before proceeding, check Understanding Support Datasheet topic for a better knowledge on information architecture.

Step 1: Enter basic data

• First of all, select ‘Clamp Base‘ on ‘Type of Support’ combo box.
• Define ‘Single/Double Type’ configuration (if double, select how you will enter loads on ‘Load Calculations’ field, by support or spring).
• Enter ‘Operational Load (Hot Load)’ value.
• Enter ‘Vertical Movement (+/-)’ value. Positive or negative values are allowed.

Advanced Setup

The design load is the largest of three

A clamp base is sized on the largest of the corrected vertical, lateral and axial loads — not on their combination. Each is corrected for temperature and material quality, and the governing one drives the selection.

This means a base with a modest vertical load and a large lateral load is sized by the lateral load.

Double supports work the other way round

For spring supports in per support mode, the entered load is divided between two elements. For a clamp base the relationship is inverted: the base carries the whole assembly, so in per spring mode the vertical load it sees is twice the value entered.

Lateral and axial loads are never doubled.

This catches people out when comparing figures on the same datasheet. It is not an inconsistency — it follows from what each component actually supports.

Lateral load limits

The lateral load must stay within a fraction of the vertical load. The fraction depends on the component series and the pipe diameter: heavier series and smaller diameters tolerate proportionally more.

Exceeding the limit does not stop the calculation. The software applies a reinforcement, which appears as a weight above the catalogue value. If you see an unexpected weight on a clamp base, this is usually why.

An anti-rotation trunnion or a double clamp base at 90º or a triple or quadruple clamp base removes the lateral check entirely, on the basis that the trunnion or the additional bases handle the lateral force.

Dimension H and the series step

Dimension H is the clear height between the pipe (BOP) and the base (TOS). It is derived from the catalogue B dimensions and the pipe radius, and averaged across the clamps on multi-clamp configurations.

Above certain thresholds of diameter or height the software steps up from the lighter base series to the heavier one. An anti-rotation trunnion forces the heavier series regardless.