CAN/CGSB-3.1000-M91

1.1 This standard defines equipment requirements, performance criteria, operating and testing procedures for the implementation of Vapour Control Systems (VCS) in gasoline distribution networks including terminals, bulk plants, service stations and cargo tanks, commonly known as Stage I. (See Figure I for schematic representation.) 1.1.1 This standard does not include vapour control systems for vehicle refueling commonly known as Stage II, rail car, marine transfers, and aviation gasoline facilities. 1.2 Intended Use - This standard has been developed to provide regulators, users, installers and compliance authorities with a uniform installation reference for Stage I Vapour Control Systems in support of the CCME Code of Practice. 1.3 Extent of Coverage - This standard provides performance criteria for equipment in use and specifies the type of interconnecting fittings to be used at terminals, bulk plants, service stations and on cargo tanks. This standard does not provide design specifications for individual components such as mechanical design of a fitting or detailed piping layout. 1.3.1 The standard also includes procedures for operating the Stage I vapour control system facilities in the various locations. Simplified schematics have been provided to illustrate possible field installations and checks. 1.3.2 The test procedures included in the document provide the basis for assessing the compliance of the equipment and systems with the requirements of the authority having jurisdiction. 1.4 Application of this Standard - The user of this standard shall refer to the CCME Code of Practice and the authority having jurisdiction in the application of this standard. 1.5 This standard has been developed, in part, prior to the availability of test data from the joint government/industry pilot project in Vancouver. It is acknowledged that certain technical elements may require reconsideration once field experience is available. 1.5.1 There is a concern that the specified maximum back-pressure of 4.5 kPa (18 in of water) at the cargo tank will not provide sufficient head to drive the Vapour Recovery Unit (VRU) process. Specified back-pressure will be reevaluated when test data are available. 1.5.2 There is a concern with the flow characteristics of poppetted vapour connections. Poppetted adaptors with low restriction to flow may be necessary for some applications. 1.5.3 There is a concern with the safety of Pressure/Vacuum (PV) vents on underground tanks; the need for such devices to improve vapour recovery is questioned. The need for PV vents is to be addressed in the GVRD project. 1.5.4 There is a concern with the suitability of U.S. Underwriters Laboratories (UL) (par. 8.2.1) flame arrestors in vapour recovery lines, and their effect on vapour flow efficiency. Flame arrestors may increase system back-pressures beyond the levels specified in par. 1.5.1. 1.5.5 Present test methods, outlined in section 7, are generally based on EPa test methods. They may be revised once additional data are gathered in the GVRD project. 1.6 Gasoline-Alcohol Blends - This standard does not address the compatibility of materials and processes for gasoline-alcohol blends in gasoline distribution networks. The owner/operator of distribution networks handling gasoline-alcohol blends shall ensure that the materials and processes of the vapour recovery facility are compatible.