Incorrect Spot Elevations Shown When Sizing Pipe

Issue

You've placed Spot Elevation callouts in your irrigation plan and are choosing to use these Spot Elevations when sizing lateral pipe or mainline pipe, but the system is either selecting the wrong elevations or you simply don't understand why it's selecting the elevations it's using.

Cause

This issue can result from:

• Lacking Spot Elevation callouts in key locations on the irrigation system, or
• Not having placed enough Spot Elevation callouts throughout the system

Solution

Step 1: Understand how Spot Elevations work with sizing pipes.

The primary step in resolving this issue requires a complete understanding of how the system uses Spot Elevation callouts when sizing pipe.

If you've used our Spot Elevation tool to account for elevation changes and select the Use Spot Elevations option when sizing your lateral or malineline pipes, any head or valve will automatically look for the nearest Spot Elevation callout and assume the head or valve is at that elevation. The system searches for Spot Elevations using a radial search pattern from each individual head in a zone or using each dead-end pipe in an Area for Dripline or Area for Drip Emitters. If the search encounters multiple Spot Elevations, the highest Spot Elevation in the searched area will be used.

Step 2: Troubleshoot your Spot Elevation issue.

The simplest method for troubleshooting spot elevation issues involves drawing a circle from the point in question to the first Spot Elevation callout encountered.

The example image to the right shows a circle drawn from the end of the lateral pipe in the drip area. The first Spot Elevation the circle encounters calls out an elevation of 4,454.8' at the location of the drip zone's valve, which has resulted in an elevation difference of 0'.

 

Note that a Spot Elevation callout has also been placed at the flush valve. The system will not originate the Spot Elevation search from components such as flush valves – only heads and pipe ends. In this example, the Spot Elevation issue could be resolved by either:

• Drawing a length of pipe should near the flush valve, or
• Placing the 4,455.7' Spot Elevation at the other lateral end