Source: http://perkofuelsystems.com/components/canister/
Timestamp: 2019-04-22 21:56:09+00:00

Document:
Carbon canisters have been used in automotive applications for decades. They filter hydrocarbons out of fumes vented during thermal expansion and/or refueling of tanks. Canisters are then purged when fresh air is drawn into the tank during thermal contraction or while the engine is running. By regulation, canisters must be protected from water and raw fuel. Both reduce their efficiency. Canister sizing is dictated by both boat and tank size.
Patented "floating bracket" allows for easy installation while reducing the transmission of torque to the canister body, end caps and spuds. The "floating bracket" also protects end caps from heat so that the factory installed heat shield is all that is needed to meet engine compartment requirements for fire protection. Builders simply install as usual with no additional effort or insulation requirements.
Hydrocarbon molecules are attracted to and stored on the surfaces of carbon pores by a physical phenomenon known as adsorption. Canister filling or adsorption occurs during two major events – thermal tank content expansion and refueling. Canister purging for marine industry will occur passively – based on vacuum created during cooling of gas and gas tank and engine use of fuel. Tank vacuum will pull ambient air through the canister resulting in desorption or purging of hydrocarbons from the canister. Purging is a function of the amount of vapor in the canister, purge air volume, and temperature.
Engine Compartment Mounting - If the canister is mounted in the engine compartment, then a heat shield is required for the canister. (to pass the coast guard fire test) The shield comes permanently mounted to the canister.
Other Mounting Locations - For non-engine compartment locations the heat shield is not required.
Mechanical - Choose a canister location that protects the canister from external impacts. Do not mount in a location where the canister will be stepped on. The mounting location should be stiff, to minimize twisting/bending of the canister body.
Temperature - The canister can withstand temperatures of 115°C continuously with 15 minute excursions to 125°C. A permanently mounted heat shield is available on the canister. It is for applications where the canister is mounted in the engine compartment and thus the canister must pass the Coast Guard fire test. The heat shield will also help if there is a short term temperature excursion, but is NOT effective for reducing a high continuous temperature.
Liquids - The canister is a hydrocarbon VAPOR control device. Allowing liquid (water or gasoline) to enter into the canister will cover the carbon and prevent it from capturing the gasoline vapors. While a one time event of getting liquid into the canister will not harm the carbon, a poorly designed system will repeatedly allow liquid into the canister and prevent the canister from functioning properly. The EPA regulations require that systems be designed to prevent liquid from entering the canister.
(d) Diurnal emissions. Installed fuel tanks must meet the diurnal emission requirements specified in 40 CFR 1060.105. Fuel tanks for personal watercraft must meet diurnal emission standards starting in the 2010 model year. Other installed fuel tanks must meet diurnal emission standards for vessels produced on or after July 31, 2011, except as allowed by §1045.625.
Percent-of-production allowances. You may produce up to 50 percent of your vessels from July 31, 2011 through July 31, 2012 that are exempt from the diurnal emission standards. Calculate this percentage based on your total U.S.-directed production volume.
Small-volume allowances. Small-volume vessel manufacturers may produce up to 1200 vessels from July 31, 2011 through July 31, 2013 that are exempt from the diurnal emission standards.
(iii) If the emission controls rely on carbon canisters, they must be installed in a way that prevents exposing the carbon to water or liquid fuel.
(b) Warranty period. Your emission-related warranty must be valid for at least two years from the point of first retail sale.
§1060.125 What maintenance instructions must I give to buyers?
Give ultimate purchasers written instructions for properly maintaining and using the emission control system. You may not specify any maintenance more frequently than once per year. For example, if you produce cold-weather equipment that requires replacement of fuel cap gaskets or O-rings, provide clear instructions to the ultimate purchaser, including the required replacement interval.
§1060.130 What installation instructions must I give to equipment manufacturers?
(a) If you sell a certified fuel-system component for someone else to install in equipment, give the installer instructions for installing it consistent with the requirements of this part.
Include the heading: “Emission-related installation instructions”.
Describe any limits on the range of applications needed to ensure that the component operates consistently with your application for certification.
Attached so it is not removable. For molded products, you may use the mold to apply the label.
Durable and readable for the equipment’s entire life.
Include your corporate name. You may identify another company instead of yours if you comply with the provisions of §1054.640.
Include EPA’s standardized designation for the emission family.
(d) You may create an abbreviated label for your components. Such a label may rely on codes to identify the component. The code must, at a minimum, identify the certification status, your corporate name, and the emission family. For example, XYZ Manufacturing may label its fuel lines as “EPA-XYZ-A15” to designate that their “A15” family was certified to meet EPA’s 15 g/m2/day standard. If you do this, you must describe the abbreviated label in your application for certification and identify all the associated information specified in paragraph (c) of this section.
(a) There are no evaporative emission standards for diesel-fueled engines, or engines using other nonvolatile or non liquid fuels (for example, natural gas).
Describe how evaporative emissions are controlled.
§1060.240 How do I demonstrate that my emission family complies with evaporative emission standards?
Design based compliance. Use of materials and designs as specified by the EPA to meet the regulatory limits.
§1060.525 How do I test fuel systems for diurnal emissions if I do not use a design based certification?

References: §1045

§1060

§1060
 §1054

§1060

§1060