Browse Topic: Evaporative emissions control systems (EVAP)
This document presents the requirements for a built-in service port to be used in vehicles intended to comply with Enhanced Evaporative Emissions Requirements. The primary function of the Service Port (Valve Assembly-Evaporative Emission Canister Purge Harness Service) is to provide non-destructive access to the evaporative emissions system to enable testing of the integrity of the system. The Service Port is used to introduce air pressure or fuel vapors into, or evacuates them out of, the system. This access may be used for the following evaluations: • Evaporative System Certifications Canister Loading and Purging • End-of-line Testing System Integrity • Service (e.g. OBD MIL on) Leak Location and Repair Verification • In-Use Compliance Testing Canister Loading and Purging • Inspection/Maintenance Testing System Integrity and Purge Check
Under contract to the EPA, Eastern Research Group analyzed light-duty vehicle OBD monitor readiness and diagnostic trouble codes (DTCs) using inspection and maintenance (I/M) data from four states. Results from roadside pullover emissions and OBD tests were also compared with same-vehicle I/M OBD results from one of the states. Analysis focused on the evaporative emissions control (evap) system, the catalytic converter (catalyst), the exhaust gas recirculation (EGR) system and the oxygen sensor and oxygen sensor heater (O2 system). Evap and catalyst monitors had similar overall readiness rates (90% to 95%), while the EGR and O2 systems had higher readiness rates (95% to 98%). Approximately 0.7% to 2.5% of inspection cycles with a “ready” evap monitor had at least one stored evap DTC, but DTC rates were under 1% for the catalyst and EGR systems, and under 1.1% for the O2 system, in the states with enforced OBD programs. Monitor readiness decreased, and DTC rates increased, as vehicles
In gasoline Powertrain systems, the evaporative emission control (EVAP) system canister purge valve (CPV) can be actuated by pulse-width modulated (PWM) signals. The CPV is an electronically actuated solenoid. The PWM controlled CPV, when actuated, creates pressure pulsations in the system. This pulsation is sent back to the rest of the EVAP system. Given the right conditions, the fill limit vent valve (FLVV) inside the fuel tank can be excited. The FLVV internal components can be excited and produce noise. This noise can be objectionable to the occupants. Additional components within the EVAP system may also be excited in a similar way. This paper presents a bench test method using parts from vehicle’s EVAP system and other key fuel system components. The test method achieves the following objectives: first, re-create the conditions that result in excitation; second, establish a controlled environment that provides insight into the noise phenomenon; and finally, set the ground work
In order to meet more stringent evaporative emissions requirements, multiple advancements in vehicle fuel system and carbon canister technologies have been made. Regardless of technological advancements, the vapor pressure of the fuel remains a vital property in controlling evaporative emissions. A series of tests were performed to explore the effects of vapor pressure on multiday diurnal evaporative emissions for 9 and 10 psi Reid Vapor Pressure (RVP) 10% ethanol (E10) gasoline-blend fuels, followed by tests with 7 psi RVP E10 gasoline on a subset of the same vehicles. A test procedure was developed to monitor evaporative emissions, canister loading profiles and breakthrough emissions for each of the fuels. A total of five vehicles were tested on all 3 fuels, blended to represent 7, 9, and 10 psi at sea level. Tests were run over 14 days using the United States (U.S.) Federal Diurnal Cycle (72°F to 96°F) in a Sealed Housing for Evaporative Determination (SHED) at a test facility in
This SAE Recommended Practice applies to nomenclature of emissions and emissions reduction apparatus as applied to various engines and vehicles. Modifying adjectives are omitted in some cases for the sake of simplicity. However, it is considered good practice to use such adjectives when they add to clarity and understanding
Exhaust and evaporative emissions systems have been developed to match the characteristics and usage of the Toyota THS II plug-in hybrid electric vehicle (PHEV). Based on the commercially available Prius, the Toyota PHEV features an additional external charging function, which allows it to be driven as an electric vehicle (EV) in urban areas, and as an hybrid electric vehicle (HEV) in high-speed/high-load and long-distance driving situations. To reduce exhaust emissions, the conventional catalyst warm up control has been enhanced to achieve emissions performance that satisfies California's Super Ultra Low Emissions Vehicle (SULEV) standards in every state of battery charge. In addition, a heat insulating fuel vapor containment system (FVS) has been developed using a plastic fuel tank based on the assumption that such a system can reduce the diffusion of vapor inside the fuel tank and the release of fuel vapor in to the atmosphere to the maximum possible extent. As a result, these
This SAE Recommended Practice is applicable to all E/E systems on MD and HD vehicles. The terms defined are largely focused on compression-ignited and spark-ignited engines. Specific applications of this document include diagnostic, service and repair manuals, bulletins and updates, training manuals, repair data bases, under-hood emission labels, and emission certification applications. This document focuses on diagnostic terms, definitions, abbreviations, and acronyms applicable to E/E systems. It also covers mechanical systems which require definition. Nothing in this document should be construed as prohibiting the introduction of a term, abbreviation, or acronym not covered by this document. The use and appropriate updating of this document is strongly encouraged. Certain terms have already been in common use and are readily understood by manufacturers and technicians, but do not follow the methodology of this document. To preserve this understanding, these terms were included and
This document presents the requirements for a built-in service port to be used in vehicles intended to comply with Enhanced Evaporative Emissions Requirements. The primary function of the Service Port (Valve Assembly-Evaporative Emission Canister Purge Harness Service) is to provide non-destructive access to the evaporative emissions system to enable testing of the integrity of the system. The Service Port is used to introduce air pressure or fuel vapors into, or evacuates them out of, the system. This access may be used for the following evaluations: • Evaporative System Certifications Canister Loading and Purging • End-of-line Testing System Integrity • Service (e.g. OBD MIL on) Leak Location and Repair Verification • In-Use Compliance Testing Canister Loading and Purging • Inspection/Maintenance Testing System Integrity and Purge Check
This SAE Recommended Practice is applicable to all E/E systems on MD and HD vehicles. The terms defined are largely focused on compression-ignited and spark-ignited engines. Specific applications of this document include diagnostic, service and repair manuals, bulletins and updates, training manuals, repair data bases, under-hood emission labels, and emission certification applications. This document focuses on diagnostic terms, definitions, abbreviations, and acronyms applicable to E/E systems. It also covers mechanical systems which require definition. Nothing in this document should be construed as prohibiting the introduction of a term, abbreviation, or acronym not covered by this document. The use and appropriate updating of this document is strongly encouraged. Certain terms have already been in common use and are readily understood by manufacturers and technicians, but do not follow the methodology of this document. To preserve this understanding, these terms were included and
This SAE Standard presents the minimum requirements for nonmetallic tubing with one or more layers manufactured for use as liquid-carrying or vapor-carrying component in fuel systems for gasoline, or alcohol blends with gasoline. Requirements in this document also apply to monowall tubing (one layer construction). When the construction has one or more layers of polymer-based compounds in the wall, the multilayer constructions are primarily for the purpose of improvement in permeation resistance to hydrocarbons found in various fuels. The tube construction can have a straight-wall configuration, a wall that is convoluted or corrugated, or a combination of each. It may have an innermost layer with improved electrical conductivity for use where such a characteristic is desired. The improved electrical conductivity can apply to the entire wall construction, if the tubing is a monowall. (For elastomeric based MLT constructions, refer to SAE J30 and SAE J2405). Unless otherwise agreed to by
In order to correspond to the exhaust emissions regulations that become severe every year, more advanced engine control becomes necessary. Engine engineers are concerned about the Hydrocarbons (HCs) that flow through the air-intake ports and that are difficult to precisely control. The main sources of the HCs are, the canister purge, PCV, back-flow gas through the intake valves, and Air / Fuel ratio (A/F) may be aggravated when they flow into the combustion chambers. The influences HCs give on the A/F may also grow even greater, which is due to the increasingly stringent EVAP emission regulations, by more effective ventilation in the crankcase, and also by the growth of the VVT-operated angle and timing, respectively. In order to control the A/F more correctly, it is important to estimate the amount of HCs that are difficult to manage, and seek for suitable controls over fuel injection and so on. Therefore, the authors have developed a HC concentration measuring technology for the air
This paper discusses an approach to detecting small leaks in an automobile's evaporative emissions systems that is a technique based upon ideal gas laws. It does this by monitoring pressure in the system while the vehicle's engine is off. This low cost solution can be easily implemented on General Motors vehicles using existing components. The topics covered in this paper include details on the background of the problem and the technique, the underlying thermodynamics of the technique, a description of the algorithm, testing and data collection considerations
This SAE Recommended Practice defines standard tube end form dimensions so as to guarantee interchangeability between all connector designs of the same size and the standard end form. This document also defines the minimum functional requirements for quick connect couplings between flexible tubing or hose and rigid tubing or tubular fittings used in supply, return, and vapor/emissions in fuel systems. This document applies to automotive and light truck applications under the following conditions: a Gasoline and diesel fuel delivery systems or their vapor venting or evaporative emission control systems. b Operating pressure up to 500 kPa, 5 bar, (72 psig). c Operating vacuum down to –50 kPa, –0.5 bar (–7.2 psi). d Operating temperatures from –40 °C (–40 °F) to 115 °C (239 °F). Quick connect couplings function by joining the connector to a mating tube end form then pulling back to assure a complete connection. The requirements stated in this document apply to new connectors in assembly
Recently, the California Air Resources Board (CARB) has proposed a new set of evaporative emissions and “Useful Life” standards, called LEVII EVAP regulations, which are more stringent than those of the enhanced EVAP emissions regulations. If the new regulations are enforced, it will become increasingly important for the carbon canister to reduce Diurnal Breathing Loss (DBL) and to prevent deterioration of the canister. Therefore, careful studies have been made on the techniques to meet these regulations by clarifying the working capacity deterioration mechanism and the phenomenon of DBL in a carbon canister. It has been found that the deterioration of working capacity would occur if high boiling hydrocarbons, which are difficult to purge, fill up the micropores of the activated carbon, and Useful Life could be estimated more accurately according to the saturated adsorption mass of the activated carbon and the canister purge volume. As a result, it is presumed that a more adaptable
This SAE Recommended Practice describes a procedure for measuring the hydrocarbon emissions occurring during the refueling of passenger cars and light trucks. It can be used as a method for investigating the effects of temperatures, fuel characteristics, etc., on refueling emissions in the laboratory. It also can be used to determine the effectiveness of evaporative emissions control systems to control refueling emissions. For this latter use, standard temperatures, fuel volatility, and fuel quantities are specified
This SAE Recommended Practice describes a procedure for measuring the hydrocarbon emissions occurring during the refueling of passenger cars and light trucks. It can be used as a method for investigating the effects of temperatures, fuel characteristics, etc., on refueling emissions in the laboratory. It also can be used to determine the effectiveness of evaporative emissions control systems to control refueling emissions. For this latter use, standard temperatures, fuel volatility, and fuel quantities are specified
This SAE Recommended Practice applies to nomenclature of emissions and emissions reduction apparatus as applied to various engines and vehicles. Modifying adjectives are omitted in some cases for the sake of simplicity. However, it is considered good practice to use such adjectives when they add to clarity and understanding
This SAE Recommended Practice describes a procedure for measuring evaporative emissions from fuel systems of passenger cars and light trucks. Emissions are measured during a sequence of laboratory tests that simulate typical vehicle usage in a metropolitan area during summer months: a A 1 h soak representing one diurnal cycle in which temperature of fuel in the vehicle’s tank is raised from 15.6 to 28.9 °C (60 to 84 °F) b A 17.9 km (11.1 mile) drive on a chassis dynamometer c A 1 h hot soak immediately following the 17.9 km (11.1 mile) drive The method described in this document, commonly known as the SHED (Sealed Housing for Evaporative Determination) technique, employs an enclosure in which the vehicle is placed during the diurnal and hot soak phases of the test. Vapors that escape from all openings in the fuel system—both expected and unexpected—are retained in the enclosure, and the increase in hydrocarbon (HC) concentration of the atmosphere in the enclosure represents the
This SAE Recommended Practice establishes uniform laboratory techniques for the continuous and bag-sample measurement of various constituents in the exhaust gas of the gasoline engines installed in passenger cars and light-duty trucks. The report concentrates on the measurement of the following components in exhaust gas: hydrocarbons (HC), carbon monoxide (CO), carbon dioxide (CO2), oxygen (O2), and nitrogen oxides (NOx). NOx is the sum of nitric oxide (NO) and nitrogen dioxide (NO2). Historical techniques still used for some purposes are included in the Appendices. A complete procedure for testing vehicles may be found in SAE Recommended Practice J1094, Constant Volume Sampler System for Exhaust Emissions Measurement. This recommended practice includes the following sections: (1) Introduction (2) Definitions and Terminology (3) Emissions Sampling Systems (4) Emissions Analyzers (5) Data Analysis and Reduction (6) Associated Test Equipment (7) Test Procedures (8) Appendices A, B, and C
The highly preferred SAE Recommended Practice for measuring evaporative emissions from fuel systems of passenger cars and light trucks is the enclosure technique detailed in SAE J171. The sensitivity and accuracy of the enclosure technique is superior to that of the trap method. This recommended practice is retained for historical reference and for use with older vehicles imported into the United States of America. In addition, this trap method is referenced in SAE J171a for making running loss measurements which cannot practically be made in an enclosure. Emissions are measured during a sequence of laboratory tests that simulate typical vehicle usage in a metropolitan area during summer months: (1) A 1 h soak representing one diurnal cycle in which temperature of fuel in the vehicle’s tank is raised from 60 to 84°F (15.6 to 28.9 °C). (2) A 7.5 mile (12.1 km) run on a chassis dynamometer. (3) A 1 h hot soak immediately following the 7.5 mile (12.1 km) run. The method for measuring
This SAE Recommended Practice describes a procedure for measuring evaporative emissions from fuel systems of passenger cars and light trucks. Emissions are measured during a sequence of laboratory tests that simulate typical vehicle usage in a metropolitan area during summer months: 1 A 1 h soak representing one diurnal cycle in which temperature of fuel in the vehicle's tank is raised from 60-84°F (15.6-28.9°C). 2 An 11.1 mile (17.9 km) run on a chassis dynamometer. 3 A 1 h hot soak immediately following the 11.1 mile (17.9 km) run. The method described in this recommended practice for measuring the weight of fuel vapors emitted during the tests differs from that described in SAE J170a (July, 1972). SAE J170a employs activated carbon traps connected to the fuel system at locations where vapors are expected to escape. Vapors from these openings are absorbed by the traps, and the gain in weight of the traps represents the fuel evaporative emissions. The method described in this report
This recommended practice applies to nomenclature of emissions and emissions reduction apparatus as applied to various engines and vehicles. Modifying adjectives are omitted in some cases for the sake of simplicity. However, it is considered good practice to use such adjectives when they add to clarity and understanding
This SAE Recommended Practice describes a procedure for measuring evaporative emissions from fuel systems of passenger cars and light trucks. Emissions are measured during a sequence of laboratory tests that simulate typical vehicle usage in a metropolitan area during summer months: 1 A 1 h soak representing one diurnal cycle in which temperature of fuel in the vehicle’s tank is raised from 60 to 84 F (15.6 to 28.9 C). 2 A 7.5 mile (12.1 km) run on a chassis dynamometer. 3 A 1 h hot soak immediately following the 7.5 mile (12.1 km) run. The method described in this recommended practice for measuring the weight of fuel vapors emitted during the tests differs from that described in SAE J170a. SAE J170a employs activated carbon traps connected to the fuel system at locations where vapors are expected to escape. Vapors from these openings are absorbed by the traps, and the gain in weight of the traps represents the fuel evaporative emissions. The method described in this report employs an
This recommended practice applies to nomenclature of emissions and emissions reduction apparatus as applied to various engines and vehicles. Modifying adjectives are omitted in some cases for the sake of simplicity. However, it is considered good practice to use such adjectives when they add to clarity and understanding
This SAE Recommended Practice describes a procedure for measuring evaporative emissions from fuel systems of passenger cars and light trucks. Emissions are measured during a sequence of laboratory tests that simulate typical vehicle usage in a metropolitan area during summer months: 1 A 1 h soak representing one diurnal cycle in which temperature of fuel in the vehicle’s tank is raised from 60 to 84 F (15.6 to 28.9 C). 2 A 7.5 mile (12.1 km) run on a chassis dynamometer. 3 A 1 h hot soak immediately following the 7.5 mile (12.1 km) run. The method described in this recommended practice for measuring the weight of fuel vapors emitted during the tests differs from that described in SAE J170. SAE J170 employs activated carbon traps connected to the fuel system at locations where vapors are expected to escape. Vapors from these openings are absorbed by the traps, and the gain in weight of the traps represents the fuel evaporative emissions. The method described in this report employs an
This SAE Recommended Practice describes a procedure for measuring evaporative emissions from fuel systems of passenger cars and light trucks. Emissions are measured during a sequence of laboratory tests that simulate typical vehicle usage in a metropolitan area during summer months: 1 A 1 hr soak representing one diurnal cycle in which temperature of fuel in the vehicle’s tank is raised from 60 to 84 F. 2 A 7 mile run on a chassis dynamometer. 3 A 1 hr hot soak immediately following the 7 mile run. The method described in this recommended practice for measuring the weight of fuel vapors emitted during the tests differs from that described in SAE J170. SAE J170 employs activated carbon traps connected to the fuel system at locations where vapors are expected to escape. Vapors from these openings are absorbed by the traps, and the gain in weight of the traps represents the fuel evaporative emissions. The method described in this report employs an enclosure in which the vehicle is placed
This SAE Recommended Practice describes a procedure for measuring evaporative emissions from fuel systems of passenger cars and light trucks. Emissions are measured during a sequence of laboratory tests that simulate typical vehicle usage in a metropolitan area during summer months: (1) A 1 hr soak representing one diurnal cycle in which temperature of fuel in the vehicle’s tank is raised from 60 to 84 F. (2) A 7 mile run on a chassis dynamometer. (3) A 1 hr hot soak immediately following the 7 mile run. The method for measuring weight of fuel vapors emitted during the test employs activated carbon traps connected to the fuel system at locations where vapors are expected to escape. Vapors from these openings are adsorbed by the traps, and the gain in weight of the traps represents the fuel evaporative emissions. The test sequence and method for measuring emissions are applicable to vehicles either with or without systems or devices to control fuel evaporative emissions. Although they
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