39930201 Spd E04 Zoning Of Hazardous Areas

Transcript

   THAMES WATER UTILITIES LIMITEDCapital DeliveryRose Kiln Court,Rose Kiln LaneReadingBerkshire RG2 0HPDOCUMENT REF:ISSUE DATE:TWUL/E04ISSUE 4.0MAY 2009 STANDARD PRACTICE DOCUMENT E04ZONING OF HAZARDOUS AREAS ISSUE 4.0DateIssuedMay 2009Manual No. Uncontrolled CopyPage 1 of 167    DOCUMENT REF: TWUL/E04SECTION 0.0 ISSUE 4.0 0.1 CONFIDENTIALITY Title to and copyright in this document vest in Thames Water Utilities Limited (TWUL).This document is CONFIDENTIAL to the recipient and members of this organisationwith a need to see it. All issued paper copies must be returned when the recipient hasno further use for it, and if he/she is an employee, all copies (electronic or otherwise)shall be surrendered on leaving the Company.Reproduction of the whole or part thereof shall not be made without the expresspermission of the Head of Capital Delivery.Page 2 of 167    DOCUMENT REF: TWUL/E04SECTION 0.0 ISSUE 4.0 0.2 CONTENTS LISTSECTION DESCRIPTION 0.1   CONFIDENTIALITY 2   0.2   CONTENTSLIST 3   0.2.1   List of Tables  10    0.3   NOTES 15   0.2.2    List of Figures  13    0.4   REGISTERED HOLDERS 15   0.5   REVIEW AND AMENDMENT PROCEDURE 15   1.0   INTRODUCTION 17   1.1   ENQUIRIES AND AUTHORS 17   1.2   GENERAL 17   1.3   SPECIFIC MEANINGS 18   1.4   GLOSSARY AND ABBREVIATIONS 18   1.4.1   Definition of Area Classification Terms  18    1.4.2    Abbreviations (used within this SPD) 22    2.0   SCOPE 24   3.0   REFERENCED MATERIAL 25   3.1   LEGISLATION 25   3.2   STANDARDS 25   3.3   OTHER DOCUMENTS 25   4.0   DSEAR COMPLIANCE 27   4.1   DESIGN OF PLANT AND EQUIPMENT 27   4.2   STORAGE OF DANGEROUS SUBSTANCES 28   4.3   CONTROL AND MITIGATION MEASURES 29   4.4   MAINTENANCE AND REPAIR PROCEDURES 30   4.5   MARKING OF HAZARDOUS AREAS 31   5.0   PRINCIPLES OF AREA CLASSIFICATION 35   5.1   INTRODUCTION 35   5.2   KEY TERMS FOR AREA CLASSIFICATION 35   5.3   HAZARDOUS AREA ZONING 35   5.4   EXTENT OF ZONE 36   5.5   NON- HAZARDOUS AREA 36   5.6   GRADE OF RELEASE 36   5.7   RELATIONSHIP BETWEEN GRADE OF RELEASE AND CLASS OFZONE 36   6.0   PROCEDURE FOR AREA CLASSIFICATION 38   6.1   ASSESSING THE RISK 38   6.1.1   Risk Assessment Process  38    6.2   DETERMINING HAZARDOUS AREAS 41   6.1.2    Flammable Liquids in Drainage Systems (FLIDS) 39    Page 3 of 167    DOCUMENT REF: TWUL/E04SECTION 0.0 ISSUE 4.0 6.2.1   Personnel  42    6.2.2    Timing  42    6.2.3    Information Required  43    6.2.4    Equipment Details  43    6.3   CLASSIFICATION OF AREAS WHERE FLAMMABLE GASES ORVAPOURS MAY BE PRESENT 45   6.2.5    Recording Area Classifications  43    6.4   CLASSIFICATION OF AREAS WHERE COMBUSTIBLE DUSTS MAY BEPRESENT45   6.4.1   Classification Procedure for Explosive Dust Clouds  46    6.4.2    Dust Layer Hazard  46    7.0   MODEL SOLUTIONS FOR SEWERAGE AND SEWAGE TREATMENTFACILITIES 48   7.1   INTRODUCTION 48   7.2   VENTILATION AND ODOUR CONTROL SYSTEMS 48   7.3   SEWERS 49   7.3.1   Domestic Foul Sewer  49    7.4   SEWAGE PUMPING STATIONS 51   7.3.2    Combined Sewer  50    7.4.1   Domestic Effluent Wet Well  52    7.4.2    Combined Effluent Wet Well  52    7.4.3    Combined Effluent Dry Well  52    7.4.4    Equipment in Wet Wells  53    7.5   STORAGE CHAMBERS AND CSO’S 66   7.4.5    Example Zoning for Sewage Pumping Stations  54    7.6   PRELIMINARY AND PRIMARY TREATMENT (INCLUDING STORMWATER STORAGE) 66   Page 4 of 167