1. Scope Part I 1.1 Subject to clause 1.2, this standard applies to pressure vessels, boilers, accessories and piping regulated by law and defined in this standard. Notes: (1) Regulations in some provinces may stipulate sizing limits different from those in this standard. It is therefore recommended to consult the regulatory authorities. (2) Cylindrical and spherical bottles, tubes and containers used for transportation, whatever the means, are governed by the Transportation of Dangerous Goods Act and the Regulations relating thereto. The requirements of this standard are not intended to contradict this law and this Regulation, nor to replace them. (3) The Anglo-Saxon values corresponding to SI (metric) units are indicated in parentheses for information purposes only. The nominal diameter of the pipes is indicated without dimensional notation. (4) The pressures indicated are gauge pressures, i.e. -i.e. greater than atmospheric pressure. 1.2 The requirements relating to piping and pressure vessels in compressed natural gas supply stations are the subject of parts two and three of standard B51-97. 1.3 This code does not apply to pressure components such as those used in elevators and hydraulic freight elevators. 1.4 In the event of a discrepancy between a clause in this standard and the codes and standards referred to therein, the requirements of this standard take precedence. Part II 1.1 This standard defines the minimum requirements for lightweight, refillable, mass-produced gas cylinders, original equipment and conversions, with a water capacity greater than 20 L (1220 cu in) but at least plus 1000 L (35.3 cu. ft.). The cylinders are only intended for the storage of compressed natural gas under high pressure, used as fuel on board the motor vehicles to which they will be attached. The type of steel, aluminum or non-metallic material, as well as the design and method of manufacturing of the cylinders, must be adapted to the prescribed conditions of use. 1.2 The cylinders covered by this standard have the following designations: (a) CNG-1 - Metal; (b) GNC-2 - Metal core reinforced with resin-impregnated continuous filaments (circumferentially wound); (c) GNC-3 - Metal core reinforced with resin-impregnated continuous filaments (fully wound); and (d) GNC-4 - Non-metallic core reinforced with resin-impregnated continuous filaments (entirely made of composite materials). 1.3 The conditions of use to which the cylinders will be subjected are described in detail in Chapter 4. This standard takes into account a service pressure of 200 bars (2900 lb/in²) for natural gas used as fuel, established at 15° C (59°F), the maximum filling pressure being 260 bar (3,770 psi). Other operating pressures can be adapted using the appropriate correction factor (ratio). A system with a working pressure of 250 bar will require, e.g. e.g., multiplying pressures by 1.25. The useful life of the bottle must be established by the manufacturer and may vary depending on the applications. The definition of useful life is based on 1000 fillings per year. The maximum useful life of GNC-2, GNC-3 and GNC-4 design cylinders is 20 years. We use, for all bottles, an “assured lifespan” calculation principle. The useful life of metal and metal core cylinders depends on the rate of fatigue crack growth. Ultrasonic inspection or equivalent of each bottle or core must be carried out to ensure the absence of defects exceeding the maximum allowable size established by fracture mechanics. This method makes it possible to optimize the design and manufacturing of lightweight cylinders used to supply vehicles with natural gas. For all-composite cylinders with non-metallic, non-load-bearing cores, calculation methods, design qualification testing and manufacturing control techniques confirm their “assured life”. 1.4 This standard does not cover the use of stainless steel or welded metal cylinders or cores. Part III 1.1 Part III of CSA B51-97 covers requirements for underground pressure piping and storage vessels used in compressed natural gas (CNG) supply stations. 1.2 The pressure pipes covered by this part are the pipe sections included: (a) between the end of the pipework of the company served, generally at the meter, and the compressor inlet of the CNG supply station, for a design pressure greater than 414 kPa (60 psi); and (b) between the compressor inlet and the distributor nozzle, except for compressor mechanical parts and subsystems designed for a design pressure of not more than 414 kPa (60 psi). 1.3 The underground storage vessels covered in this section are pressurized and are installed at CNG supply stations; they are used to store CNG intended for vehicle fuel tanks.
CSA B51-1997 history
1970CSA B51-2019 Code sur les chaudières, les appareils et les tuyauteries sous pression
2014CSA B51-2014 Code sur les chaudières, les appareils et les tuyauteries sous pression (Dix-huitième édition; Mise à jour no 1: Décembre 2014)
2009CSA B51-2009 Code sur les chaudières, les appareils et les tuyauteries sous pression
1998CSA B51-1997 Code des chaudières, appareils et tuyauteries sous pression
1995CSA B51-1995 Boiler, Pressure Vessel, and Pressure Piping Code