BS pdf - Download as PDF File .pdf), Text File .txt) or read online. Abandonment 3 Pipeline design flowchart 3. Section 2. Design. BRITISH STANDARD. BS Incorporating Amendment No. 1. Code of practice for. Pipelines — Part 2: Pipelines on land: design, construction and. PD , Code of practice for pipelines — Part 2: Subsea pipelines. For example, BS EN excludes pipeline systems for the.
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British Standard A single copy of this British Standard is licensed to Licensed Copy: Akin Koksal, Bechtel Ltd, 29 March , Uncontrolled. BS PD Pipeline systems – Part 2: Subsea pipelines – Code of practice. Secure PDF. Single User. $ Print. In Stock. Need it fast? Ask for rush. of you have this Standard: BS Part-1 (General Pipeline Onshore) and BS Part 2, BS Ductile Iron pdf MB.
These and other definitions included in this Section are based, where applicable, on BS , Part 2. Submittals shall be in accordance with the procedures specified in Section 1, in this Part and in the other Parts of this Section. These shall be submitted to the Engineer or his nominated representative for approval before the contract completion date.
Electronic format record sheets shall be obtained from the Engineer or his nominated representative. Backfilling will not be permitted prior to the record sheets being approved. The Contractor shall also locate by co- ordinates the position of buried bends and fittings on pressure mains. Where pipelines are not laid to straight lines between chambers or fittings the co-ordinates of every pipe joint shall be recorded prior to covering up the pipeline. Where flexible pipes are used coordinates shall be at 10m intervals.
The Contractor shall use the Site for the purposes of constructing the Works only. In the absence of satisfactory evidence of equivalent testing results, materials will be required to pass the day acid test as detailed in Clause 1.
The test shall be carried out by an approved laboratory, experienced in undertaking the test. Such materials may be divided into two categories: Category 1 Materials - material which serve a purpose other than protection e.
Care shall be taken in preparation of samples of non-homogenous materials to ensure that only the face that will be exposed to the corrosive environment in the sewer is exposed to the acid during the testing. The concentration of acid shall be maintained by preventing evaporation. In addition the strength of the acid shall be regularly checked and the level and strength adjusted as necessary. The second sample shall be kept as a control. Ethylene has the lowest critical pressure of commonly transported gases.
Toxic liquids will behave in a similar manner. The behaviour of gases and associated liquids in two phase flow pipelines will depend upon their particular composition on release. The risk analysis should culminate in an evaluation of risk along the pipeline. Crude oil and petroleum products radiate a high level of heat on ignition. Ammonia will radiate heat if ignited. Liquefied petroleum gas LPG is flammable and. When ignited it radiates heat and may produce a vapour cloud explosion.
LPG will radiate a high level of heat on ignition. Ethane is flammable. Ethylene radiates a high heat on ignition and can form a vapour cloud which may migrate from the point of rupture. Hydrogen is flammable. For pipelines conveying category C substances and having a design factor not exceeding 0.
The proximity distances for pipelines conveying category C substances at pressures less than 35 bar should be the same as those for the substance calculated at 35 bar. Class 1 location Areas with a population density less than 2. The minimum distance in metres for routing purposes between a pipeline having a design factor see 2. For pipelines conveying category D substances and having a design factor not exceeding 0. The location of category B substance pipelines need not be classified in relation to population density but may require extra protection or be subject to a safety evaluation.
Class 2 location Areas with a population density greater than or equal to 2. Q Ammonia 2. Additional factors should be considered when classifying pipeline location such as future development. Q is the substance factor see Table 2. P is the maximum operating pressure in bar. Table 2 — Substance factors Substance Substance factor. Class 3 location Central areas of towns and cities with a high population and building density.
The minimum distances should finally be determined by taking into account factors including the hazardous nature of the particular substance being conveyed and the pipeline inventory in conjunction with a safety evaluation of the pipeline see 2.
In these and other comparable cases a more stringent classification of location may be considered where the effects of a pipeline failure could be experienced by population centres outside the immediate vicinity of the pipeline.
The measurement of population density is described in 2. Occasionally the method of population density assessment may lead to an anomaly in classification of location such as may occur in a ribbon development area or for pipelines conveying toxic substances.
For category C and category D substance pipelines. The population should be estimated following consultation with local authorities to assess the population level in the area concerned. Assessments of traffic densities should be carried out by consultation with the Department of Transport and local highway authorities concerned.
Major roads would normally include motorways and trunk roads. It is essential that pipelines designed to operate in class 3 locations be limited to a maximum operating pressure of 7 bar. Private roads or tracks should only be classified as minor roads if there is reason to believe that they may be used regularly by heavy traffic.
Minor roads would normally include all other public roads. Measurement of population density should be based on a survey of normally occupied buildings including houses. In such cases consideration should be given to a more stringent classification than would be indicated by population density alone. In areas of high population density extensively developed with residential properties.
The point at which the required degree of protection changes adjacent to the boundary between class 1 and class 2 areas should be one-half of the appropriate strip width from the boundary of the higher density area. However the design factor may be raised to a maximum of 0. Pipelines designed to convey category D substances in class 2 locations should have either a nominal wall thickness of 9.
For pipelines designed to operate at less than 7 bar. Where it is necessary to utilize pipe bridges these should be designed in accordance with good structural engineering practice and with a design factor in accordance with 2. See 6. Minor rail routes would normally include all others. Assessment of traffic densities and crossing requirements should be carried out by consultation with the appropriate railway authority.
For major roads the design factor. Account should be taken of accessibility requirements for maintenance and of restrictions on access to the general public. Particular care should be exercised in the consideration of ground conditions and temporary works design.
Consideration should be given to the provision of impact protection at open-cut crossings of major roads. The minimum distance between the road surface and the top of the pipe or sleeve should be 1.
In considering additional protection.
Sufficient headroom should be provided to avoid possible damage from the movement of traffic or shipping beneath the pipe bridge. The minimum distance between the top of the pipe or sleeve and the top of the rail should be 1. Pipe bridge design should consider thermal and structural stresses. Major rail routes would normally include inter city and high density commuter routes. Pipeline crossings of minor roads should be carried out using either: Pipeline crossings of major roads should be carried out using either: Potential cathodic protection interference between the pipeline and bridge supporting structure should be considered.
Cathodic protection systems should be designed in accordance with BS Unless otherwise recommended in this standard impact protection should extend between the highway or railway boundary at each side of the crossing. Important factors to be considered include: The spacing of section isolating valves should reflect the conclusions of any safety evaluation prepared for the pipeline and should preferably be installed below ground. Where pipelines are unavoidably located in such areas.
For the depth of cover in other areas reference should be made to BS In the locating of section isolating valves account should be taken of topography.
This distance may be increased if it can be justified to a statutory authority as part of a safety evaluation of the pipeline. These may include increased wall thickness. Consideration should be given to similar installation on pipelines conveying category C and non-toxic category B substances. Where particular circumstances indicate the need for a sleeved crossing.
Impact protection may take the form of increased cover. It is essential that the MAOP does not exceed the internal design pressure. Where pipelines are connected to wells. The leak detection system should be part of the overall pipeline management system which should incorporate route inspection in accordance with BS The maximum operating pressure is the sum of the static head pressure. The MAOP is related to the test pressure established by carrying out a hydrostatic or pneumatic test on the pipeline in accordance with section 8.
Typical leak detection methods include continuous mass balance of pipeline contents. See Figure 3 for a review of pressure definitions. The weight effects described in 2. The internal design pressure used in design calculations may be modified by taking into account the difference in pressure between the inside and outside of any pipeline component.
Pipeline systems should be designed for the most severe coincident conditions of pressure. Allowances for pressure rises above maximum operating pressure due to surges are described in 2. The method chosen for leak detection should be appropriate and effective for the substance to be conveyed. Provision should be made for the effects of thermal expansion or contraction in the design of pipeline systems.
The effects of longitudinal expansion due to internal pressure should be taken into account in the design of pipeline systems. Account should be taken of stresses induced as a result of restriction of free thermal movement owing to restraints. Flanges exceeding or departing from standard dimensions may be used provided they are designed with reference to BS ANSI B Surge pressure calculations should be carried out to assess the maximum positive and negative surge pressures in the piping system.
Appendix II: Bolts or studbolts should extend completely through the nuts. Special gaskets may be used providing they are suitable for the pressures. Division 1. For treatment of corrosion allowance see 2. Account should be taken of surge pressures produced within the pipeline affecting piping systems outside the scope of this standard such as upstream of pumping stations or downstream of pipeline terminals.
A nominal pipe wall thickness should be selected to give adequate performance in construction handling and welding. Section VIII. Gaskets should be designed in accordance with BS See 5. ANSI B An indication of wall thinning as a percentage may be given by the following empirical formula: Factory-made bends and factory-made wrought steel elbows may be used provided they comply with 2.
Division 1: The installation of threaded joints including compression fittings should be discouraged on buried piping systems. Reference should be made to 3. Sufficient tangent lengths should be left at each end of bends to ensure good alignment. All bends should be free from buckling.
Pipes bent cold should not contain a butt within the bent section. Consideration should be given to the installation of valves to a fire safe design in safety critical areas.
Where welded or forged branch connections are installed in pipelines designed for pigging. The design of special joints should take account of vibration. This formula does not take into account other factors which depend on the bending process and reference should be made to the bend manufacturer where wall thinning is critical.
Account should be taken of the use of cleaning. End closures for components including pig traps. Special steel and non-ferrous valves may be used providing their design. Before installation into the pipeline. Valves having pressure-containing components such as body. The wall thickness of finished bends. The nominal internal diameter of a bend should not be reduced by ovality by more than 2.
The design should ensure that the hinges and locking mechanism are sufficiently robust to withstand repeated use. For above-ground multipipe-type slug catchers the pressure design should be in accordance with ANSI B The allowable hoop stress is given in 2. Sh is the hoop stress calculated in 2.
In both cases reference should be made to BS When carrying out flexibility and stress analysis calculations account should be taken of momentum and dynamic effects. Welding and inspection requirements should be supplemented by BS NOTE Additional forces may need to be considered. A is the cross sectional area of the pipe wall in mm2. The axial compressive force required to restrain a pipeline should be calculated as follows. The design should take account of static loading.
Pig traps should be tested at pressures not less than those required for the associated pipeline. The hoop stress should be calculated by using either the thin wall or thick wall design equations.
Consideration should be given to thermal relief. The design pressure should be equal to the internal design pressure of the pipeline system see 2. Design of anchor blocks to prevent axial movement of a pipeline should take into account the pipeline expansion force and any pipe to soil friction preventing movement. A pipeline should be considered totally restrained when axial movement and bending resulting from temperature or pressure change is totally prevented.
In the absence of more directly applicable data. The effect of restraints. Account may be taken of any extra flexibility of such components. In such cases expansion calculations should be carried out taking into account all the forces acting on the pipeline.
Thermal expansion or contraction of buried pipelines may cause movement at termination points. Account should be taken of buckling forces which may be imposed on pipelines laid in active mining areas. The temperature range used in the calculation of reactions on anchors and equipment should be the difference between the maximum or minimum metal temperatures and the installation temperature. D is the outside diameter in mm. The thick wall design equation gives a more accurate calculation of hoop stress and always gives the smallest value of maximum stress.
Consideration should be given to elastic instability due to longitudinal compressive forces. The necessary flexibility should be provided if such movements are unrestrained. Expansion calculations should be carried out on buried and above-ground pipelines where flexibility is in doubt and where significant temperature changes are expected such as occur in heated oil or refrigerated pipelines.
This gives the maximum hoop stress encountered at the inside face of the pipe wall. Di is the inside diameter D — 2t in mm. Where movement is unrestrained. Above ground pipelines and piping may be restrained by anchors so that the longitudinal movement owing to thermal and pressure changes is absorbed by direct axial compression or tension of the pipe. SF is the shear force applied to the pipeline in N.
For unrestrained sections of a pipeline. The equivalent stress should be calculated using the von Mises equivalent stress criteria as follows: SL is the total longitudinal stress as defined in 2. Z is the pipe section modulus in mm3. A p is the internal design pressure in bar.
NOTE The von Mises equivalent stress has been derived from the full equation by assuming that the third principal stress is negligible. The maximum number of stress cycles expected for a pipeline should be evaluated by multiplying the number of daily cycles occurring within a given stress range by C in Table 4.
Reference should be made to CP The sum of factored and unfactored cycles should not exceed 15 No external corrosion allowance is required if both an anti-corrosion coating system and a cathodic protection system are installed. Account should be taken of the differences between installation and operating temperatures in relation to axial stresses see 2.
Where internal corrosion. Thermal insulation systems should be designed to retain the substance being conveyed within its process design limits at the lowest design flow rates. Where a corrosion allowance is applied it should be added to the value of the design thickness see 2.
Differences in coefficient of thermal expansion of the various materials and the pipe should be considered. If the pipe history is unknown.
Thermal insulation may be built up from layers of different materials selected according to the temperature gradient through the system. Vapour barriers should be installed to prevent the migration of moisture within the insulation and subsequent damage to the pipeline material.
More complex daily stress cycles should be evaluated by multiplying the number of individual stress cycles. For refrigerated pipelines the possibility of frost heave should be considered. Since the risk of external corrosion at elevated temperatures is higher than at ambient temperatures and since above ground coating damage inspection techniques are ineffective. Braces and damping devices may be required to prevent vibration of piping.
The encircling member should be welded by continuous circumferential welds. Attachments to the pipeline should be designed to keep within safe limits the additional stresses in the pipe wall caused by the attachment. Supports should be designed to support the pipe without causing excessive local stresses in the pipe. Where a piping system or pipeline is designed to operate at. Friction forces at the supports should be considered in evaluating the flexibility of the system.
Consideration should be given to the depth of cover of heated or refrigerated pipelines in agricultural land in respect of thermal effects on crop growth. Non-integral attachments such as pipe clamps are preferred where they will perform the supporting or anchoring functions.
Butt-welded pipe should not be supplied. This should be carried out before significant quantities of linepipe are produced to ensure compliance with the chemical and mechanical properties in the specification.
Where pipelines are required to be pneumatically tested. Limitations on bolting materials are given in 2. Refer to API 5L. Consideration should be given to the significance of temperature on the performance of materials.
Where the substance to be transported requires that special materials should be used. Plates BS Steels for use in chemical.
Those materials exposed to low temperatures should have adequate fracture toughness at the design temperature. BS Steels for fired and unfired pressure vessels. Consideration should be given to the completion of a manufacturing procedure qualification test on linepipe to be specially manufactured for a specific pipeline. Limitations on gasket materials are given in 2.
Cast iron should not be used for pressure-containing components. Sections and bars BS Part A: Materials specifications-ferrous None Unfired fusion welded pressure vessels BS To ensure resistance against brittle or ductile running fracture.
The pipe should also comply with the additional recommended requirements in 3. Traditional methods of bend manufacture by the hot-forming process furnace bends may differ in their effect upon the pipe mechanical properties when compared with more modern methods e. Unless the method is well established with a continuous history of successful manufacture in the range of bend materials and dimensions concerned. Particular care should be taken with methods which involve quenching as part of the process.
Advantage may be taken of pipe delivered with certified mechanical properties better than the specified minimum values and measured wall thickness greater than the design thickness. The level of testing and acceptance criteria should be similar to that required in the manufacturing procedure qualification test for the parent pipe see 3. Internal corrosion may be caused by the corrosive effect of the substance being transported and may be controlled by a combination of corrosion inhibitors.
Above-ground sections of pipelines should be electrically isolated from the buried sections and should not carry cathodic protection currents. Coatings should also exhibit strong adhesion and resistance to cathodic disbondment at holidays.
Field-applied coatings for bare pipe. See 4. Consideration should be given to the use of a hard abrasion-resistant compatible external coating such as a polyurethane or two component epoxy resin system where coated pipe is to be installed by thrust boring or similar methods.
Above-ground pipes should be protected from atmospheric corrosion by a suitable coating or paint system. Consideration should be given to the control of corrosion as described in 4. Factory-applied external coating materials may be glass-reinforced coal-tar or bitumen in accordance with BS and BS Account should also be taken of the internal coating in the selection of pigs to prevent damage during pigging.
If pipes are joined by welding such that metal is exposed. For components of irregular shape. The external coating of other below ground components forming part of the pipeline system should be designed in conjunction with the cathodic protection system and other coatings on the pipeline.
If a spirally-applied tape wrapping system is used. When selecting an external factory-applied coating. A factory-applied coating is preferred for all pipeline components to ensure adequate surface preparation and coating application under controlled conditions. Anti-corrosion coatings should be selected to reflect the varying ground conditions found during a soil and resistivity survey carried out along the pipeline route.
A cathodic protection system should be installed to reduce this corrosion. Cathodic protection may be applied by the sacrificial anode or impressed current method and should be designed and constructed in accordance with BS The cathodic protection system should be brought into operation as soon as possible following pipeline construction and where delays are unavoidable the use of temporary sacrificial anodes should be considered.
The corrosion inhibitor selected should not cause deterioration of any components in the piping system or of the substance being conveyed. The application of cathodic protection to a pipeline may cause adverse effects on other buried metallic structures close to the protected pipeline and the procedures of BS The effects of high turbulence in the performance of inhibitors should be considered.
Inhibitor injection equipment should be included in the design. Account should also be taken of noise generated by piping and equipment in the design of station piping.
Consideration should be given to topography. It does not include piping systems such as 3 Applications process plant piping within refineries, factories or treatment plant The pipelines covered by this Section of BS are generally suitable for conveying water, sewage, 2.
When used for the conveyance of sewage, a connection that is designed to permit angular reference should be made to BS , BS , deflections or axial movement, or a combination of BS and BS GRP pipes and fittings both, in service, without impairing the efficiency of are particularly suitable for pipelines in locations the joint where corrosive environments exist either NOTE See Appendix A. Any liner, if necessary, and limitation of flow velocity sub-standard materials or workmanship should be to reduce erosion; rectified or, where necessary, rejected.
Materials 6 General A clear indication should be given on all valves of the direction of rotation needed to close the valve. A variety of resin systems and reinforcement The direction of rotation should be the same for any structures may be used to make GRP pipes and one pipeline installation. Different direction of closure as clockwise. Flanges may be made from a variety of materials 7 Pipes including GRP or steel, but it is essential that those used are compatible with the use of the pipeline.
Flanges complying with other NOTE These standards specify diameters, lengths, standards may be used for particular purposes. Unless otherwise specified by the downloadr, PN 16 8 Fittings flanges are usually supplied and are therefore suitable for working pressures up to and GRP fittings and relevant aspects of fittings made including 16 bar, particularly for water industry from other materials should comply with BS applications.
The use of high tensile bolts of smaller diameter than the corresponding mild steel MS bolts to 9 Valves facilitate manufacture and installation of larger 9. BS gives details All material used in valves should be compatible of the bolt hole diameters for such flanges.
Such with the products which are to be conveyed in the flanges will be marked accordingly. Where high pipeline. For use with potable water, see the tensile bolts are used with flanges holed for mild requirements given in Appendix B.
Washers should comply with BS