The Seraphin® 5 Gallon (20 Liter) Vapor Retention Prover (VRP™) is a graduated neck, bottom drain vessel built to N.I.S.T. Handbook 105-3 Standards, OIML R-120, Measurement Canada and API Manual of Petroleum Measurement Standards Chapter 4. Using Seraphin's® 5 Gallon (20 Liter) VRP™ can speed the job of calibrating multiple fuel dispensing units, while at the same time, enhancing safety and productivity. It eliminates the need to carry heavy measures filled with fuel while tripling the amount of meters tested as compared to the traditional hand held units.

The VRP™ has a cap mounted on its neck that creates a seal around the dispenser nozzle as the prover is filled and drained also a vent line is fitted from the top of the prover to the product holding tank on which the prover is mounted. The neck is sealed with a flapper and boot to prevent evaporation and retain saturated air during the drain-fill cycle. The volume standard, holding tank and vent line configuration is such that when the prover is drained, the air in the storage tank, which is saturated with gasoline vapor, is drawn through the vent line into the prover, thereby maintaining a saturated environment within the prover. The VRP™ comes with a Flanged Ball Joint that is bolted to a tank and a quick disconnect for removal.

Designed for easy transport and assembly, the Seraphin® Portable Calibration Cart can speed the job of calibrating multiple fuel dispensing units, while at the same time, enhancing safety A popular application is for use maneuvering around docks while calibrating Marina pumps.

The unit is constructed of light weight aluminum components for quick and easy assembly. The 45 Gallon (170 Liter) holding means multiple tests can be preformed prior to wheeling the cart to the fuel station’s underground storage tanks for dumping.
Unit of Measure


Tank Capacity

N/A 45 gal170 L

Tire Size

N/A 8 in


N/A Aluminum

Prover Material

N/A Stainless Steel

Prover Capacity

N/A 5 gal20 L


N/A API Manual of Petroleum Measurement Standards Chapter 4. Measurement Canada N.I.S.T. Handbook 105-3 Standards OIML R-120

Drain Valve Size

N/A 1-1/2 in

Drain Hose Length

N/A 6 ft

Camlock Size

N/A 2 in


  • The cart consists of 4 lightweight components: cart, tank prover and handle
  • The 45 Gallon (170 Liter) holding tank is supported with four pneumatic 8” tires
  • Seraphin’s ® 5 Gallon (20-Liter) Stainless steel VRP™ bottom drain prover is supported by a swiveling ball joint for leveling.
  • Straps ground all components to each other and a strap is provided to ground the unit to the dispenser
  • The drain valve is a 1-1/2” ball valve and a 6 ft quick connect fuel drain hose
  • To comply with Measurement Canada a Drip Point device is available
  • 2” Camlock Quick Disconnect Fittings permits rapid locking and unlocking of the prover to the ball joint so that the prover can be easily removed and stored