Drag Reducing Agent (DRA) Injector Setpoint Management Application Programming Interface (API)

The Drag Reducing Agent (DRA) Injector application provides two methods for managing the rate of DRA injecting into the line:

• Calculated — Injector pump setpoint value is determined as a function of target concentration (parts per million [ppm]) and current flow rate.

• Setpoint Lookup — Injector pump setpoint value is determined by looking up this value given the DRA Product Group and the target flow rate range.

The DRA Injector Setpoint Lookup method provides an Application Programming Interface (API) to allow the import of setpoint values for a number of stations on a given line.

The following table provides an example of the type of lookup table that is meant to be managed by this interface for a particular DRA Injector.

The above table represents a set of DRA injection setpoints that can be associated with a DRA Injector. The DRA Injector application will determine which of these setpoints to send to the field device during operation based on the intersection of the DRA Product Group and the DRA Flow Rate Range that are in effect.

Note: The values used for these two parameters are also definable on a per-pipeline basis using this API.

The following diagram provides an overview of the system topology that DRA Injection Setpoint Management is intended to support.

To effectively use the DRA Injector Setpoint Management Interface, the following base configurations are required:

• DRA Injector devices

• DRA Injector Groups (based on location)

• DRA Lines

In addition to this, the system-wide set of Product Types that DRA Injectors will be injecting into must be defined.

The following diagram details entity relationship involved in the DRA Injector Setpoint Management.

In the diagram above, the tables colored green represent persistent configuration that is managed using the Advanced Database Editor (ADE) and promoted using Management of Change (MoC). The contents of the blue tables are populated using the DRA Injector Setpoint Management Interface. These tables contain configuration parameters that affect the run-time functionality of the DRA Injector application, but they are not manually managed or maintained through ADE.

The following sections provide the necessary background and usage information to enable you to implement an application that will populate the DRA Injector Setpoints using this API.