ORVR FAQ (For StationWatch.com)

ORVR

(Onboard Refueling Vapor Recovery)

FAQ (Frequently Asked Questions)

Frequently Asked Questions (FAQs) as of April 06, 1998.

Follow links to answers below.

FAQ001 What, exactly, is ORVR?

FAQ002 What, in general, does Vapor Recovery mean?

FAQ003 What is meant by Stage(Phase) I Vapor Recovery?

FAQ004 What is meant by Stage(Phase) II Vapor Recovery?

FAQ005 Why do we need ORVR?

FAQ006 What is the schedule for implementation of ORVR?

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FAQ001 What, exactly, is ORVR?

The initials ORVR stand for Onboard Refueling Vapor Recovery.

The concept of ORVR is to include a system within an automobile (or similar automotive vehicle) such that vapors accumulated in the fuel tanks, as well as new fuel vapors generated during refueling, are captured within the vehicle ("onboard") rather than depending on external methods (known as Stage II vapor recovery) to efficiently collect the vapors before they can escape into the atmosphere.

Current ORVR technologies generally consist of Activated Carbon Canisters (ACC) which absorb the hydrocarbons (HCs) contained in the vapors forced out of the vehicle while refueling is occurring.

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FAQ002 What, in general, does Vapor Recovery mean?

In the context of ORVR and Stage II vapor recovery, Vapor Recovery means the collection of the vapors that would normally escape into the atmosphere (and into the lungs of the motorist) while a vehicle is being refueled. The vapors so collected would be either stored in the Fuel Storage Tank or processed in some manner. In the past vapor recovery systems that address this problem have been termed Stage II vapor recovery systems, with Balance and Vacuum Assist being the major forms of Stage II systems. With the introduction of ORVR, the vapors are not supposed to even be able to leave the vehicle, making the use of external vapor recovery systems unnecessary.

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FAQ003 What is meant by Stage(Phase) I Vapor Recovery?

Stage I vapor recovery is the term applied to the control of vapors during the transfer of fuel from a fuel distribution point via tank trucks to the refueling sites (service stations). In Stage I (called Phase I in some areas), the tank trucks are equipped with a dual hose system, and the Fuel Storage Tanks (FSTs) are equipped with two mating ports for these hoses. One port is for the fuel to be delivered to the FST, and the second port is for the vapors in the FST (in the volume above the liquid fuel level) to be returned to the tank truck. In essence, the tank truck arrives with a full tank of liquid fuel, and exchanges the same volume of liquid fuel for a volume of vapors that were in the FST. The tank truck returns the fuel vapors to the fuel distribution center where they are again exchanged for a volume of liquid fuel. What the distribution center does with the vapors is outside the interests of the ORVR group, but the vapors are essentially recovered and, supposedly, reprocessed.

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FAQ004 What is meant by Stage(Phase) II Vapor Recovery (VR)?

Stage II vapor recovery means the external collection of the vapors that would normally escape into the atmosphere (and into the lungs of the motorist) while a vehicle is being refueled. The vapors so collected are returned to the Fuel Storage Tank (FST), essentially taking up the same volume in the FST that the dispensed fuel occupied. Balance and Vacuum Assist systems are the major types of Stage II systems. With the introduction of ORVR, the vapors are not supposed to even be able to leave the vehicle, making the use of external vapor recovery systems (Stage II) unnecessary. The challenge for existing Stage II VR systems is to continue to efficiently collect vapors from non-ORVR vehicles, while being compatible with ORVR vehicles. Vacuum assist systems will need additonal control logic or vent processor systems to prevent over pressurization of the vapor volume ("ullage") of the Fuel Storage Tanks.

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FAQ005 Why do we need ORVR?

Very good question. ORVR was a very good idea over 20 years ago when the question of collecting the fuel vapors during refueling first became a national health priority. However, it was realized that it would take over 20 years for all motor vehicles to be converted to ORVR, so the EPA (and CARB) decided to implement Stage II, which could be mandated and enforced in a much shorter time frame. However, instead of beginning ORVR conversion at that time as well, no further consideration was made for ORVR (as far as mandated implementation is concerned) until recently when it was mandated nationally to begin in 1998. We are now in the slow, 20 year conversion that began with the 1998 model year automobiles. Only in 1997 did the obvious concern about compatibility with the existing Stage II VR systems (especially vacuum assist systems) become seriously examined.

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FAQ006 What is the schedule for implementation of ORVR?

To the best of our knowledge, the schedule now is as follows:

Automobiles: 40% of 1998, 80% of 1999, and 100% of 2000 and beyond models were to be equipped with ORVR. (A small percentage of total us auto population for many years.)

"Light Duty Trucks" and similar vehicles: 40% of 2001, 80% of 2002, and 100% of 2003 and beyond models were to be equipped with ORVR.

"Medium Duty Trucks" and similar vehicles: 40% of 2004, 80% of 2005, and 100% of 2006 and beyond models are to be equipped with ORVR.

Heavy Duty Trucks and other Vehicles: Not sure if they will ever be required to have ORVR. Last we heard, it was still a discussion item.

CARB Projections

The projections for ORVR penetration in gasoline fueled vehicles for the State of California is given here. The ealier 1998 projection has been updated with CA Motor Vehicle data up to 2002.

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