Status: Alert Withdrawn. Norwegian title: Oil and Gas Pipeline Systems and Commentary on CSA Standard Z, Oil and Gas Pipeline Systems. English title. CSA Special Publication Z Commentary on CSA Standard Z, Oil and Gas Pipeline Systems Published in June by Canadian Standards. Hyperlinks from the Z Standard to the corresponding clauses in the Z and. Special Publication. Z Commentary on CSA Standard.
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Brittle fractures could thus propagate indefinitely because the crack tip during a pipeline rupture would continue to be under the stress associated with the pre-rupture pipeline pressure. All of the applicable welding variables described in Clauses 7. This provision is intended to accommodate short runs of aboveground pipe in compressor stations, for which it was considered that there had been a history of satisfactory performance with Category III pipe, and that long propagating fractures could not occur because the pipe run length is restricted to m maximum.
It is intended that such consideration during planning the pipeline should be a basis for increasing the class location designation, not decreasing it. Prior tofabricated assemblies specifically included items such as separators, mainline valve assemblies, cross connections, and river crossing headers. Plastic Pipelines This was intended to clarify that a facility does not become a pump station or a compressor station merely because a pump or compressor is present in the facility.
Z Commentary on CSA Standard Z
Two notes have been added to the bottom of this table to provide some clarification. This critical proximity distance became 90 m in with the change to SI units and was eliminated equivalent to being changed to m in with the publication of the first edition of the Standard. This distance was chosen to define a generally acceptable limit for the zone of influence of surface loads on a buried pipeline; it is based upon the results of a 2: Wilson and is a compilation of revisions to the previous Commentary, including additional comments pertaining to all substantive changes that have been cwa to the edition s662 CSA Z When a sufficient amount of reinforcement is provided for branch connections, z6622 stress level in the crotch can be held down to acceptable levels; however, when this reinforcement is a saddle or pad, tests indicated that a concentration of stress occurs at the points where tangents to the outside circumference of the pad are parallel to the axis of the header.
Such features only influence the class location length in those locations that would have a Class 1 or 2 location designation based upon all other considerations. Consequently, the stresses at the crack tip that promote fracture propagation are rapidly diminished, and z6662 propagating fractures do not occur.
At the present time there is no consensus on the specific manner in which heat input values are to be calculated or documented e. Accordingly, a number of requirements in CSA Z Such engineering assessments shall give consideration to a number of factors, as itemized in Items a to g.
For example, a currently Class 4 location should not be designed as a Cza 2 location because it is foreseen that a number of three- or less storeyed buildings intended for human occupancy are going to be constructed in the class location assessment area cs the four- or more storeyed buildings intended for csz occupancy will no longer be prevalent. June 39 Z Class location designations are determined on the basis of class location assessment areas m wide by 1.
Secondary containment and leak detection are required as additional items because such design issues are not addressed in the National Fire Code of Canada. The notch toughness properties are required to be proven at or below the applicable design temperature, in order to ensure that the required notch toughness properties will be available during pressure testing and in service.
Half-circumference test joints are not permitted for qualification of welders for branch connection or fillet welds, or for qualification of welding procedures of any size or configuration. For welds produced by mechanized or automatic welding, requalification is required if the filler metal size is 30 to a size that is different from the size that was used to qualify z62 welding procedure specification.
The option of using an earlier edition of a materials standard or specification than that listed in Clause 2 is an acknowledgement that many materials manufactured to an earlier edition may still be suitable for the intended use. Figure 10 illustrates three possible outcomes, with Sketch b based upon a literal interpretation of Table 4.
The 27 J minimum requirement applies to fittings having ca grade of Grade or sca, flanges NPS 24 or larger, and pressure-containing valve parts having a grade of Grade or higher. Centrifugal pumps were moved to sca new Clause 4. In addition, the external stresses imposed on the pipeline, the potential for third-party damage due to reduced awareness of the location of buried piping, and other factors that may contribute to accidents also increase with increasing population.
Gas that contains an average of 7 mg or less of hydrogen sulphide per cubic metre is considered to be csx gas for contractual delivery purposes i. Any required testing for notch toughness properties is to be done at or below the applicable minimum design temperature for the piping, in order to ensure that the required amount of notch toughness will be available during pressure testing and in service. Carbon dioxide is a liquid while contained, but becomes a gas when released; accordingly, carbon dioxide pipelines are treated somewhat like gas pipelines, with Category II pipe being required for all design operating stresses greater than 50 MPa.
The purpose of the Commentary is to provide background information concerning certain clauses and requirements in the Standard, to provide information that may be of assistance to the reader in the understanding and implementation of such requirements, and to refer to research materials that were used during the formulation of some of the requirements in the Standard. In addition, the use of straight alignment aids in the process of predicting and identifying the location of the pipeline in the field.
Depending on interpretation, this clause enabled the designer to limit the extent of Class 2 and Class 3 locations to m beyond the last dwelling unit in the cluster. These additional requirements only apply to materials having a specified minimum yield strength higher than MPa 56 psi because it is recognized that the carbon equivalent value may not be readily known for materials having a specified minimum yield strength of MPa or less.
Standards Council of Canada
As such, the pipe could be marked with the API monogram. Experience has shown that pipeline ruptures can occur during hydrostatic testing or service because of damage that occurred during the installation process but was not detected and repaired. This requirement was not carried forward into the first edition of the Standard because it was noted that there was no specific requirement for the company to have construction specifications, procedures, and quality assurance standards.
The PTSV1 value for As an alternative to repairing the defective pipe, the affected portion of pipe can be cut out as a cylinder and replaced with another pipe that meets the design requirements. This was Table 4. Although it is not stated, it would be prudent additionally to inspect each piece to determine its suitability for the intended service, as is required in Clause 5.
Operating, Maintenance, and Upgrading Prior tothe limit on ovality in CSA Z was 2. As defined in Table 7. Wording was also added to recognize that welding procedures for pipe to components and components to components may also be qualified in this manner. For service fluids consisting of gases that exhibit two-phase decompression behaviour, it is common practice to determine the fracture arrest toughness by using the two-curve method developed by Battelle for the Pipeline Research Committee of the American Gas Association, which involves matching an empirically calculated fracture speed curve to the decompression curve characteristic of the gas in the pipeline.
For example, where there are two roads 1. As a result, all of the joining clauses from 7. The least nominal wall thickness for threaded pipe inside compressor or pump stations is equivalent to Schedule 40 for pipe A playground, for example, may often be vacant; however, if it is likely that more than 20 persons will be present when it is being used, it will affect the class location designation if the class location assessment area would otherwise be a Class 1 location.
This enables Class 1 location pipelines to be upgraded for service in Class 2 locations without replacement with heavier wall pipe. It is recognized that where upgrading involves the replacement of existing piping with new piping, what was not practical for the old piping is practicable for the new piping.
Prior to for gas pipelines and for oil pipelines, the design factor varied, depending upon the class location or zone. This new clause was necessary due to the deletion of centrifugal pumps from Clause 4. You need to log in before adding standards to the monitoring service.