The PLC carefully monitors the operation of the control solenoid. The unique pressure switch, utilized by OdorEyes, reports to the PLC each time the solenoid valve operates properly. An alarm is also generated if the solenoid fails in the closed mode.

EcoSystem B/U units utilize the most modern technology available. Should you experience a problem or failure of the PLC, you need not return the entire unit for repair. The PLC is modular, meaning the failed unit can be replace quickly by a new unit shipped via overnight carrier. It is not necessary to disconnect any wires or make any major changes to the system

Basic System Components

Regulator
The system regulator is sized for the flow and pressure required. This is determined by the information supplied by the user with the order. Regulators are equipped with a pressure gauge used for setting the outlet pressure. Outlet pressure should be set for approximately 40 psi above the downstream pressure.

Solenoid Valve
The EcoSystem B/U has a 24 VDC, two-way solenoid valve. The control solenoid is operated by the PLC each time the system pulses. The amount of gas flowing to the tank is determined by the dwell time of the control solenoid. By increasing or decreasing the dwell time, more or less gas can be passed to the tank, thereby increasing or decreasing the injection rate and resets the unit if a failure is indicated. A power-fail circuit provides a safe power-down sequence and subsequent restart.

Gas Flow Meter
The PLC will accept either an analog or digital signal from any type gas flow meter. The meter signal must be representative of instantaneous gas flow in the pipeline. Meters which store pulses and dump them periodically are not acceptable. Pulses must be delivered to the PLC as flow occurs, Digital signals should be in the form of a dry contact. Analog signals my be 1-5 VDC or 4-20 ma dc. Meters may be furnished by the user or by OdorEyes Technologies, Inc.

Odorant Storage Tanks
Storage tanks may be supplied as an integral part of the system or the user may supply them separately. Tanks supplied by OdorEyes Technologies are certified and ASME code stamped with the proper pressure rating for the system. Note that bypass tanks operate at pipeline pressure and must be sized accordingly. Optional relief valves, sight level gauges, skids and containment pans, and other accessories may be obtained as part of the total system package.

Tank Level
The Accu/Level electronic tank measurement system is designed specifically to work in conjunction with the EcoSystem B/U This highly accurate device works with any size odorant tank, but it must be properly sized and the PLC programmed accordingly. The Accu/Level transmitter sends a 4-20 ma do signal to the PLC. This signal denotes the tank level inside the tank.

Temperature Detector
The EcoSystem B/U utilizes a resistance-type temperature detector installed in the tank to allow the system to properly adjust for temperature changes.

The temperature signal is used to compensate for temperature changes in the tank, which directly affect the tank pressure. This allows for the accuracy of the level reading. The PLC maintains a running inventory of the tank level. This information may be programmed in pounds, gallons, inches, ETC. The signal is also used to alter the pulse rate of the odorizer based on temperature (absorption rate changes with temperature). This maintains the accuracy of the odorizer itself.

Programmable Logic Controller
The PLC is a 24 VDC logic controller specifically programmed for odorization, It consists of a modular rack, input/output cards as required and an operator interface keypad. In case of complete power failure, memory is protected by the PLC back-up battery.