Automet® FAB - Shoe & Trunnion Base Plate Measurement
Overview
Pipe support base plates (such as shoe supports and trunnion supports) follow a measurement sequence similar to flange surveys. Observations define the spatial plane, orientation, and thickness of the support base plate relative to the pipe centerline.
Shoe Support Measurement Sequence
Edge point capture
Edge points define the plane and perimeter of the support base plate. Measurements can be taken using either a Type 7 or Type 9 device adapter. The Type 9 adapter is particularly useful when base plates are too thin to support the Type 7 device securely.
If the underside edge of the plate is accessible, it can be measured as an alternative to the top edge.
Minimum edge point configuration
At a minimum, **three edge points** must be recorded:
- Two points on one edge.
- One point on an adjacent edge.
- Constraint: The two measured edges must **not** be parallel to each other.
Back point capture
The back point establishes the orientation of the base plate edge points relative to the pipe run.
- Placement: Always capture the back point on the support structure heading toward the pipe centerline.
Stop point capture
The stop point measures the physical thickness of the base plate and instructs automet® FAB to complete the feature capture routine.
- Placement: Must be taken on the opposite face of the base plate relative to the edge points.
- Restricted access (deck/surface contact): If the opposing face is resting directly against structural steelwork or a deck surface, place the prism ball directly on the supporting surface adjacent to the plate to capture the stop point.
Trunnion Support Base Plates
Trunnion support base plates are surveyed using identical edge, back, and stop point workflows as shoe supports.
