Attachment 1 - Installation Instructions and Specifications.pdf

16 August 2021

Installation Instructions

Requirement Name: Repairs and Upgrades to South Linear Move Irrigation System

General Information:

1. Purpose and Objectives of the Acquisition:

The existing 3-span lateral move sprinkler irrigation system is used in several long-term irrigation experiments at USDA-ARS, Bushland, Texas, and is part of a multi-location and multi-institution research program. The program objectives are to compare crop water use and water use efficiency as affected by irrigation application method (drip and sprinkler), irrigation rates (full, deficit, and dryland), crop varieties and rotation, and management (planting rates, planting dates, tillage and residue management, etc.). This requires that sprinkler packages on the lateral move be changed frequently, sometimes several times in one day in order to irrigate the multiple experiments. This imposes substantial time and labor requirements to field operations and makes maintaining experimental treatments difficult.

The addition of a VRI system to the lateral move would substantially reduce time and labor by eliminating the need to constantly change sprinkler heads. In addition, the VRI system would increase the ability to randomize treatments within each experiment, resulting in much stronger statistical analyses.

Finally, the pump that delivers water from the irrigation reservoir to the linear move is approaching the end of its life, thus needs replacing. In addition, the existing pump does not have variable frequency drive required for the VRI sprinkler system.

CONTRACTOR INSTALLATION REQUIREMENTS:

2. Technical Requirements/Tasks:

Existing Lateral Move System:

The VRI system is to be installed to an existing Valley lateral move irrigation system (model

6000). The existing lateral move is oriented north-south and operates in an east-west direction.

Water is supplied by a 4-inch drag hose; water is pressurized by a nearby centrifugal pump, conveyed through an underground PVC pipeline, and connected to the drag hose by several risers along the direction of travel of the lateral move. The lateral move has a cart with a diesel-powered generator on the south end, which supplies power to the wheel motors. The lateral move has 3 spans, with each span approximately 128 ft in length. Each span has 24 sprinkler drops spaced 5 ft apart, for a total of 72 drops in the entire 3-span system. Sprinkler applicators used typically have a flow rate of up to 6.5 gpm, with a total system flow of up to 470 gpm.

VRI Specifications:

Each VRI zone can have up to 6 drops, or a minimum of 12 zones. VRI valves should maintain up to 6.5 gpm to each drop. The control panel and firmware should, at minimum, include GPS and accommodate direct upload of VRI prescriptions. Upgradable panel and firmware options should include upload of prescriptions and control of a variable frequency drive pump by telemetry.

Specific tasks to be performed by the vendor include transportation of all components to the 3-span lateral move, assembly of all components into a working system, and start up and test of the system as detailed in Part G below.

VFD pump specifications:

New variable frequency drive and pump system will be installed. The pump will have the capability to operate at a rated flow of 350 gallons per minute. The drive and pump should be able to operate between 80 and 250 psi. The drive and pump minimum recommended motor rating is 25 hp. Pump needs to be centrifugal in operation and 3 phase 480 volts. The new drive and pump need to communicate with the linear move’s control panel.