Installation pipework on industrial and commercial premises

Transcription

1 Communication 1729 Installation pipework on industrial and commercial premises Founded 1863 Royal Charter 1929 Patron: Her Majesty the Queen

2 Communication 1729 Installation pipework on industrial and commercial premises Price Code: C6S The Institution of Gas Engineers and Managers Charnwood Wing Holywell Park Ashby Road Loughborough, Leics, LE11 3GH Tel: Fax:

3 CONTENTS SECTION PAGE 1 Introduction 1 2 Scope 4 3 Legislation and standards Pressure Equipment Directive Health and Safety at Work etc. Act (HSWA) Management of Health and Safety at Work Regulations (MHSWR) Gas Safety (Installation and Use) Regulations (GS(I&U)R) Gas Safety (Management) Regulations (GS(M)R) Electricity at Work Regulations Control of Substances Hazardous to Health Regulations (COSHH) Control of Asbestos at Work Regulations Gas Appliances (Safety) Regulations Gas Cooking Appliances (Safety) Regulations Reporting of Injuries, Diseases and Dangerous Occurrences Regulations (RIDDOR) Provision and Use of Work Equipment Regulations (PUWER) Confined Spaces Regulations Building Regulations Construction (Design and Management) Regulations (CDM) Pressure Systems Safety Regulations (PSSR) Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) 11 4 Planning and design Planning Design Gas flow rate Gas pressure Gas velocity Calculation of flow, pressure drop and velocity Pressure test and purge points Gas filters Valves and connections Facilities for hydrostatic testing Gas supply line diagram Materials General Protection of components prior to construction Selection General Carbon steel Stainless steel Polyethylene (PE) Copper Corrugated stainless steel tube (CSST) Sleeving IGEM, Holywell Park, Charnwood Wing, Ashby Road, Loughborough, Leicestershire, LE11 3GH Website:

4 6 Jointing Carbon and stainless steels General Welding Polyethylene (PE) Copper Corrugated stainless steel tube (CSST) Protection of pipework General Stored pipework Installed pipework Associated components Identification and labelling General General Fusion jointing General Brazing and soldering 27 7 General principles for installing pipework General Location of pipework Construction and sleeving Clearances Electrical safety General Electrical isolation Earthing Additional emergency control valves (AECVs) Additional manual isolation valves Non-return valves (NRVs) etc Traps Purge points Pressure test points Secondary and check meters Automatic isolation valves (AIVs) Gas detectors Additional emergency control valves (AECVs) Manual section isolation valves Ancillary equipment Valves and equipment Pipes and pipework Provision for connections Plant pipework 39 8 Buried pipework General Route Depth and position in the ground Protection of buried pipework General Corrosion Cover Identification of buried pipework components 43 IGEM, Holywell Park, Charnwood Wing, Ashby Road, Loughborough, Leicestershire, LE11 3GH Website:

5 9 Entry into and exit from buildings Types of entry and exit Steel Polyethylene (PE) Delicate wall constructions Conditions of use General Semi-rigid coupling and flange adaptor Bellows Swivel joint Quick release coupling Flexible tube or hose Suitability Sleeving and sealing Materials Pipework in ducts, etc. in buildings General Design of ducts, ceiling voids, etc Ventilation of ducts etc Unventilated ducts and voids Pipework in multi-storey and multiple-dwelling buildings General Materials Support Jointing Laterals Buildings containing domestic type premises Pipework support Flexible connections General Pressure loss across hoses Manual valves Features Selection Position indication Overtravel Speed of operation Fire resistance Double seals Pressure drop Applications Consumer s check meter Section isolation Buried or below ground Plant isolation Valve types 60 IGEM, Holywell Park, Charnwood Wing, Ashby Road, Loughborough, Leicestershire, LE11 3GH Website:

6 14.11 Servicing Compressors, boosters and pre-mix machines Installation Protection equipment Schematic installation diagrams Non-lubricated plug Lubricated plug Ball Wedge and parallel slide gate Butterfly Diaphragm Vents and breathers General Vents Breathers from regulators and related safety devices Location Ventilation Mounting Pipe connections Electrical connections Statutory requirements Further protection (pre-mix machines) Boosters Pre-mix machines Wiring Notices Operating data Commissioning, operation, maintenance and servicing Commissioning Operation, maintenance and servicing Procedures on completion of installation General Maintenance planning 77 APPENDIX 1 Glossary, acronyms, abbreviations, symbols and units 79 2 References 84 3 Gas flow through pipework 89 4 Wall thickness of pipework 92 5 Types of flexible connections 94 6 Selection of a gas supply protection system 97 7 Weep by-pass pressure proving systems Gas detection systems Low pressure cut-off switches 109 IGEM, Holywell Park, Charnwood Wing, Ashby Road, Loughborough, Leicestershire, LE11 3GH Website:

7 10 Commissioning Typical record of new installation Calculating allowable pressure loss Pressed fittings. Jointing procedure 116 FIGURES 1 Operational pressure limits 2 2 Typical gas supply line diagram 19 3 Example of an AECV label 34 4 Lever-operated AECV with on/off labels fitted 37 5 Positioning gas marker tape 38 6 Yellow Natural Gas tape 38 7 Yellow LPG tape 38 8 Yellow gas tape 38 9 Typical section of pipe in footways Typical buried pipework under a roadway Marker plate for syphons, valves and purge points Typical above-floor entry - steel pipework Typical below-floor level entry - steel pipework Typical pre-fabricated below-ground entry. PE pipe in a steel sleeve Typical entry PE pipe from above ground Single booster installation Parallel booster installation Fan-type mixer Compressor-type mixer Schematic drawing of possible wiring circuit (boosters) Warning notice near to the meter inlet valve and any gas compressor or gas engine Warning notice on installation pipework Mechanically jointed semi-rigid coupling Flange adaptor 94 IGEM, Holywell Park, Charnwood Wing, Ashby Road, Loughborough, Leicestershire, LE11 3GH Website:

8 25 Swivel joints Typical layout for a weep by-pass proving system Typical limiting orifice Low pressure cut-off valve Typical schematic wiring diagram for 3 phase starter 110 TABLE 1 Maximum allowable pressure drop 15 2 Maximum gas velocity related to filter size 16 3 Jointing of carbon and stainless steels 24 4 Screwed and welded carbon and stainless steel connections 24 5 Welding standards 25 6 Inspection and testing of steel welds 26 7 Inspection and testing of PE fusion welds 27 8 Inspection and testing of brazed and soldered joints 28 9 Minimum proximity of buried pipe parallel to buildings Minimum depth of cover Free area of ventilation openings Supporting above-ground pipe Suitability of flexible connections Valve types and features Suitability of valves Approximate flow in straight horizontal pipes with 1.0 mbar pressure differential between extremes for ρ gas = 0.6 (ρ air = 1.0) and with 2.5 mbar differential for ρ gas = 1.5. MOP 75 mbar. Pipe lengths 5 m to 250 m Wall thickness of carbon steel pipe Wall thickness of stainless steel pipe 93 IGEM, Holywell Park, Charnwood Wing, Ashby Road, Loughborough, Leicestershire, LE11 3GH Website:

9 SECTION 1 : INTRODUCTION 1.1 This Standard supersedes IGE/UP/2, Communication 1598, which is obsolete. 1.2 This Standard has been drafted by an Institution of Gas Engineers and Managers (IGEM) Panel, appointed by IGEM s Gas Utilization Committee, and has been approved by IGEM s Technical Co-Ordinating Committee on behalf of the Council of IGEM. 1.3 This Standard covers the design, installation, operation and maintenance of gas installation pipework which includes compressors, boosters and pre-mix machines but now with an upper limit on discharge pressure of 0.5 bar, on industrial and commercial premises. This Standard also includes advice on weep by-pass pressure-proving systems, formerly contained in BG IM/20 which is superseded and is obsolete. The scope has been extended to include pipework downstream of a plant isolation valve but not pipework that would normally be defined as appliance pipework i.e. as pre-installed in the appliance by its manufacturer. 1.4 This Standard applies to new installations only. It is not retrospective but it is recommended that existing installations be modified to meet this Standard, when appropriate. 1.5 New terms such as maximum operating pressure (MOP), maximum incidental pressure (MIP) and operating pressure (OP) have been introduced to reflect gas pressure terminology used in European standards. These terms will arise in all relevant IGEM Standards in future and, possibly, in other standards. Other new terms have been introduced to assist in recognition of design information to be transferred between interested parties. Of particular note are lowest operating pressure (LOP) and design minimum pressure (DmP). Referring to Figure 1, attention is drawn to how OP oscillates about the set point (SP). Note also that MOP can be declared at a higher value than OP. The strength test pressure (STP) has to be at least MIP and, in many cases, will exceed MIP. This means that, at least with respect to integrity, the installation will withstand a fault pressure from the upstream system. 1.6 This Standard makes use of the terms should, shall and must when prescribing particular requirements. Notwithstanding Sub-Section 1.9: the term must identifies a requirement by law in Great Britain (GB) at the time of publication the term shall prescribes a requirement which, it is intended, will be complied with in full and without deviation the term should prescribes a requirement which, it is intended, will be complied with unless, after prior consideration, deviation is considered to be acceptable. Such terms may have different meanings when used in legislation, or Health and Safety Executive (HSE) Approved Codes of Practice (ACoPs) or guidance, and reference needs to be made to such statutory legislation or official guidance for information on legal obligations. 1 IGEM, Holywell Park, Charnwood Wing, Ashby Road, Loughborough, Leicestershire, LE11 3GH. Website:

10 STP MIP MOP Pressure SP OP time STP = Strength test pressure MIP = Maximum incidental pressure OP = Operating pressure MOP = Maximum operating pressure SP = Maximum set point of, typically, the active regulator. FIGURE 1 - OPERATIONAL PRESSURE LIMITS 1.7 The primary responsibility for compliance with legal duties rests with the employer. The fact that certain employees, for example responsible engineers, are allowed to exercise their professional judgement does not allow employers to abrogate their primary responsibilities. Employers must: have done everything to ensure, so far as it is reasonably practicable, that responsible engineers have the skills, training, experience and personal qualities necessary for the proper exercise of professional judgement have systems and procedures in place to ensure that the exercise of professional judgement by responsible engineers is subject to appropriate monitoring and review not require responsible engineers to undertake tasks which would necessitate the exercise of professional judgement that is not within their competence. There should be written procedures defining the extent to which responsible engineers can exercise their professional judgement. When responsible engineers are asked to undertake tasks which deviate from this, they should refer the matter for higher review. 1.8 It is now widely accepted that the majority of accidents in industry generally are in some measure attributable to human as well as technical factors in the sense that actions by people initiated or contributed to the accidents, or people might have acted in a more appropriate manner to avert them. It is therefore necessary to give proper consideration to the management of these human factors and the control of risk. To assist in this, it is recommended that due regard be paid to HS(G) Notwithstanding Sub-Section 1.6, this Standard does not attempt to make the use of any method or specification obligatory against the judgement of the responsible engineer. Where new and better techniques are developed and proved, they should be adopted without waiting for modification to this Standard. Amendments to this Standard will be issued when necessary, and their publication will be announced in the Journal of the Institution and other publications as appropriate Requests for interpretation of this Standard in relation to matters within its scope, but not precisely covered by the current text, should be addressed in writing to Technical Services, IGEM, Charnwood Wing, Holywell Park, Ashby Road, Loughborough, Leicester, LE11 3GH and will be submitted to the relevant Committee for consideration and advice, but in the context that the final responsibility is that of the engineer concerned. If any advice is given by or on 2 IGEM, Holywell Park, Charnwood Wing, Ashby Road, Loughborough, Leicestershire, LE11 3GH. Website:

11 behalf of IGEM, this does not relieve the responsible engineer of any of his or her obligations This Standard was published on 1 st April A lead-in period is allowed permitting the use of Edition 1 until 1 st July IGEM, Holywell Park, Charnwood Wing, Ashby Road, Loughborough, Leicestershire, LE11 3GH. Website:

12 SECTION 2 : SCOPE Acronyms and abbreviations Units CSST = Corrugated Stainless Steel Tubing mm = millimetres GS(I&U)R = Gas Safety (Installation and Use) Regulations LPG = Liquefied Petroleum Gas MOP = Maximum Operating Pressure NG = Natural Gas PE = Polyethylene PED = Pressure Equipment Directive PSR = Pipelines Safety Regulations 2.1 This Standard applies to installation pipework and pipework downstream of any plant isolation valve that is not "appliance pipework", on industrial and commercial premises. Note 1: For the purposes of this Standard, installation pipework also embraces compressors, boosters and pre-mix machines (see Sub-Section 2.5). Note 2: This Standard also will be applicable for pipework exceeding 35 mm diameter on domestic premises. Note 3: For pipework not exceeding 35 mm diameter on domestic premises, and carrying a 2 nd family gas, BS 6891 and IGE/G/5 (for multiple dwelling buildings) apply. Note 4: For pipework on domestic premises, carrying a 3 rd family gas, BS 5482 applies (an upper size limit is not stated). Note 5: Pipework upstream of a meter installation and, hence, upstream of installation pipework, is covered by the Pipelines Safety Regulations (PSR), IGE/TD/4, IGE/TD/3, and IGE/TD/1 respectively. Note 6: Meter installations are covered by BS 6400, IGE/GM/4, IGE/GM/6 and IGE/GM/8, respectively. 2.2 This Standard deals with the design, installation, operation and maintenance of pipework, including selection of materials and components. 2.3 This Standard applies to pipework designed to contain 2 nd family gas, for example Natural Gas (NG), and 3rd family gas in the gaseous state, for example liquefied petroleum gas (LPG). Note: It is likely that many of the requirements will be appropriate for 1 st family gases, for example Towns Gas, and other fuel gases, including those generated from landfill sites, but account will need to be taken of their different constituents and the consequent effect on materials and operations. 2.4 This Standard applies for MOP not exceeding 5 bar. For MOP exceeding 0.5 bar on industrial premises, any additional/more-stringent requirements in BS EN may have to be applied. Note 1: The scope of BS EN is limited to industrial piping. IGEM/UP/2 generally is considered suitable for all installations of MOP not exceeding 5 bar but compliance with BS EN is in effect a legal requirement for MOP exceeding 0.5 bar for industrial piping as it is a means of legal compliance with the Pressure Equipment Directive (PED). Note 2: For MOP not exceeding 5 bar on commercial premises, installations fall under the Gas Safety (Installation and Use) Regulations (GS(I&U)R). BS EN does not apply and IGEM/UP/2 is considered equivalent to, and more comprehensive than, BS EN Note 3: IGEM/UP/2 no longer addresses installations of MOP exceeding 5 bar (Edition 1 covered up to 7 bar). For such installations, it is recommended that reference be made to appropriate standards such as BS EN This Standard applies to pressure-raising machines having a discharge pressure limited to a maximum of 0.5 bar. Note: For higher discharge pressures, requirements are given in IGE/UP/6. 4 IGEM, Holywell Park, Charnwood Wing, Ashby Road, Loughborough, Leicestershire, LE11 3GH. Website:

13 2.5 This Standard considers specifically pipework of steel, stainless steel (including corrugated stainless steel tubing (CSST)), copper and polyethylene (PE). In certain applications, the use of other materials may be specified, when such materials are required to be used in accordance with appropriate standards and/or the principles of this Standard for materials of similar properties. When considering components of pipework, for example valves, this Standard covers a large selection of materials. However, the information is subject to the manufacturer's specification for the material in question. 2.6 This Standard applies to new installations only (see Sub-Section 1.4). 2.7 This Standard covers installation arrangements made in accordance with IGE/G/ The term "diameter" refers to nominal inside diameter for carbon and stainless steels and to nominal outside diameter for copper and PE, unless otherwise stated (for example when "nominal bore" is the relevant parameter). 2.9 Pressures quoted are gauge pressures unless otherwise stated Italicised text is informative and does not represent formal requirements Appendices are informative and do not represent formal requirements unless specifically referenced in the main sections via the prescriptive terms should, shall or must. 5 IGEM, Holywell Park, Charnwood Wing, Ashby Road, Loughborough, Leicestershire, LE11 3GH. Website: