Overview of Meter Proving and Calibration for The influence of vapor on calibration

Gasoline Inventory Challenges Fuel Terminal to Automobile Tank.

Automobile Improvements (Background Information) The automobile industry has implemented the Onboard Refueling Vapor Recovery System (ORVR). They call it “Capless Fueling” or “Easy Fuel”. ORVR was required by the Federal Government to be installed in all newly manufactured vehicles in The new system enables the vapors that were once vented into the air or captured by the Stage II Vapor recovery system to be retained inside the automobile and used to fuel the engine. The significance of this is that there is not anymore vapor lost at the fill neck of an automobile when refueling.

Components in a positive displacement meter (Background Information) Cylinder Wall Piston Cup Piston Roller Camshaft Cam

Meter Wear Primary Causes of Unaccounted Fuel Slippage (Dispensing More Than What is Registered): 1.Wear to the piston cups and the cylinder walls. 2.Wear between the valve seat, valve, and counter-valve (when present). 3.Wear to the cam and the piston roller assemblies. 4.Wear to the camshaft bearings, valve keyhole & key (when present). How Meters Wear Over time, the various surfaces which rub against one another will wear and result in minute changes in the dimensions of the various components. Also, if there is grit present in the fuel, the rate of wear will be greatly accelerated. In many older meters, there is a center cavity in which debris can be trapped, accumulate, and can accelerate wear to piston cups and cylinder walls, camshaft bearings, piston roller assemblies, and the cam. Source PMP Corporation

Manufacturer’s recommended calibration schedule Source Gilbarco

Open Neck Prover Method of Operation Fill Prover with 5 gallons of gasoline. View product level on the meniscus. Determine variance

How does vaporization impact meter calibration? When using an open neck prover a small amount of fuel is vaporized when dispensing fuel in the prover. The fuel that is vaporized is not in the prover. Therefore it appears on the miniscus of the prover that vaporized fuel was not dispensed because it is not in the prover. The reality is that it was dispensed however it vaporized

Vapor Elimination Prover (VEP) Specialized Prover used by Crompco’s AccuMeasure Crews

Running Multiple Tests is Important The first 5 gallons cannot be used for accurate meter proving. (see above) Crompco does run a second Fast Flow Test on each meter to ensure repeatability. A Slow Flow Test is run on every meter prior to sealing the meter. As a result a minimum of 20 gallons is run per meter. Approximately 6 meters per store required calibration to be completed twice or more in order to achieve repeatability within the.5 in³ protocol.

Benefits of the VEP VEP eliminates the effects of vaporization in meter proving. The system is very repeatable which will enable the technician to calibrate meters to “0”. VEP is designed & built to National Institute of Standards & Technology Handbook Specifications. –This means it is accredited by NIST & approved by all W&M Agencies. –The results are traceable to NIST’s National Standards. The provers are exclusively developed by Seraphin for Crompco.

Math Behind Metering We have studied the effects of vaporization on calibration and determined that vaporization accounts for approximately.2% of product loss during meter testing/calibration. How much is.2%? –.2% of 5 gallons (which is 1155 in³) is.010 gallons (2.31 in³) per five gallons. –.2% of 1,000,000 gallons is 2,000 gallons Our goal with AccuMeasure is to save as much of the vapor/gasoline loss as possible.

The loss trend on both products change after AccuMeasure was completed. The stage II vapor recovery causes an increase in fuel especially on the Regular product. The calibration improved the Regular by approximately 309 gallons per month. The site pumps approximately 1, gallons per year Corresponding Gasoline Inventory to AccuMeasure Results

Meter Variance & Product Loss