Stammen & Associates

Validation Systems

Get the most from your RVP analyzer.

The U.S. Environmental Protection Agency and the California Air Resources Board have issued tighter limits on Reid Vapor Pressure (RVP) in Blended Gasoline. The costs to refiners resulting from these new rules are estimated to be over $200 million/year.

An increase in accuracy of each tenth of a pound (0.1 psi) in the RVP measurement can save an average refinery several hundred thousand dollars per year. This has brought about the need not only to reliably measure RVP on-line, but also to prove the repeatability of the analysis.

The Stammen & Associates RVP Validation System connected to an ABB Model 4100 Low Range (0-20psi) RVP analyzer will automatically prove the repeatability of the analyzer online.

The system consists of a constant pressure cylinder containing a pure validation material with a known RVP value, a double-block and bleed valve manifold with leak detection, sample pressure regulator and PLC with touch screen display.

The PLC monitors the analyzer cycle time, alarm status, and output signal. A man-machine interface allows an operator to conveniently enter data as well as monitor and control all aspects of the validation process.

The sample or validation material is selected by the PLC and flows through the double block and bleed valve and pressure regulator to the analyzer. This minimizes sample transport time, yet conserves validation material. The pressure regulator insures all samples to the analyzer are injected at the same pressure.

The PLC can be programmed to start validation by an external contact closure or by time of day and the day of the week.

The system components includes:

Allen Bradley PLC,
10.5" Quickpanel Touch Screen Color Display with stainless steel bezel, in a Stainless Steel Nema 4X enclosure,
Explosion proof Stainless Steel high/low pressure switch on piston pressure,
Dual block and bleed stainless steel valve manifold with Kalrez seals for oxygenated gasoline service,
Stainless Steel regulators on sample and piston nitrogen pressure,
Stainless Steel valve manifold leak detector with components for nitrogen blanket,
Stainless Steel Division II solenoid valves,
Welker Stainless Steel piston cylinder modified for low pressure applications,
All stainless steel tubing with Swagelok fittings

Items that are typically required to implement the online validation system:

Modifying the existing analyzer sample handling system.
Eliminate existing syringe sample introduction system.
Connect sample stream to validation system’s valve manifold.
Install RS-232 interface to existing analyzer if not already provided.
Connect RS-232 interface to validation system.
Connect 115 VAC power to validation system.
Run "Cycle Reset" and "End of Cycle" contacts from analyzer to Validation System.
Run validation system alarms to refinery control system.
Run analyzer signal from validation system to refinery control system.
Run plant nitrogen to validation system.
Run pure nitrogen to validation system.
Run validation system's manifold valve leak detector to liquid drain system.

For a written quotation, please call PE Systems at 714-671-0660.