Service: Automation and Control

Control Strategies

• Assistance with the design, commissioning, startup, documentation, and troubleshooting of instrumentation and control strategies for gas metering facilities.

• Flow computers are being asked to do much more than calculations related to gas measurement. Many are being used for monitoring auxiliary systems such as intrusion, gas detection, filter separator operation, multiple parameter (flow with pressure override) flow control and run switching.

• Flow control and run switching strategies must be based on failure modes. This tact is critical to ensure continuous and correct operation of the facility. Shut-in of the downstream customer do to flow control valve problems or run switching valve problems can have devastating and costly consequences

• Many companies utilize bi-directional flow through a meter station o economically handle gas from or to multiple customers. This is usually done in one of two ways. The first is by having the gas from two or more different sources go through the meter station in only one direction. The flow directions are handled by remotely operated block valves in a manifold configuration. The flow computer must be configured with the correct amount of input/output (I/O) to handle all of the valve inputs and statuses. The flow computer must also be programmed to correctly control flow direction with a remote command from the SCADA system or from the flow computer’s local interface. The second method involves utilizing the bi-directional capabilities offered by ultrasonic meters. Transmitters, pulse trains and/or digital signals must come into the flow computer for both directions. The flow computer needs to handle volume calculations, audit trail, averaging and historical record keeping for both directions as separate meter numbers.

Services Offered:

Measurement
• Lost and Accounted For
• Instrumentation
• Gas Meters
• Meter Stations
• Integration

Automation and Control
• Control Strategies
• Flow Computers
• Communication

Additional Services
• White Papers