HUMAN FACTORS ENGINEERING - VALVES

Transcription

1 DEP INFORMATIVE HUMAN FACTORS ENGINEERING - VALVES Copyright Shell Group of Companies. No reproduction or networking permitted without license from Shell. Not for resale DEP Gen. ECCN EAR99 DESIGN AND ENGINEERING PRACTICE 2011 Shell Group of companies All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, published or transmitted, in any form or by any means, without the prior written permission of the copyright owner or Shell Global Solutions International BV. This document contains information that is classified as EAR99 and, as a consequence, can neither be exported nor re-exported to any country which is under an embargo of the U.S. government pursuant to Part 746 of the Export Administration Regulations (15 C F.R. Parts 746) nor can be made available to any national of such country. In addition, the information in this document cannot be exported nor re-exported to an end-user or for an end-use that is prohibited by Part 744 of the Export Administration Regulations (15 C F.R. Parts 744).

2 Page 2 PREFACE DEP (Design and Engineering Practice) publications reflect the views, at the time of publication, of Shell Global Solutions International B.V. (Shell GSI) and, in some cases, of other Shell Companies. DEP-Informatives provide the main rationale for certain requirements and recommendations in the companion DEP-specification with the same number. DEP-Informatives are intended for internal use by the Principal only. The right to obtain and to use DEPs is restricted, and is typically granted by Shell GSI (and in some cases by other Shell Companies) under a Service Agreement or a License Agreement. This right is granted primarily to Shell companies and other companies receiving technical advice and services from Shell GSI or another Shell Company. Consequently, and because DEP-Informatives are only intended to be used by representatives of the Principal, two categories of users of DEP-Informatives can be distinguished: 1) Operating Units having a Service Agreement with Shell GSI or another Shell Company. The use of DEPs by these Operating Units is subject in all respects to the terms and conditions of the relevant Service Agreement. 2) Other parties who are authorised to use DEPs, subject to appropriate contractual arrangements (whether as part of a Service Agreement or otherwise). Subject to any particular terms and conditions as may be set forth in specific agreements with users, Shell GSI disclaims any liability of whatsoever nature for any damage (including injury or death) suffered by any company or person whomsoever as a result of or in connection with the use, application or implementation of any DEP, combination of DEPs or any part thereof, even if it is wholly or partly caused by negligence on the part of Shell GSI or other Shell Company. The benefit of this disclaimer shall inure in all respects to Shell GSI and/or any Shell Company, or companies affiliated to these companies, that may issue DEPs or advise or require the use of DEPs. Without prejudice to any specific terms in respect of confidentiality under relevant contractual arrangements, DEPs shall not, without the prior written consent of Shell GSI, be disclosed by users to any company or person whomsoever and the DEPs shall be used exclusively for the purpose for which they have been provided to the user. They shall be returned after use, including any copies which shall only be made by users with the express prior written consent of Shell GSI. The copyright of DEPs vests in Shell Group of companies. Users shall arrange for DEPs to be held in safe custody and Shell GSI may at any time require information satisfactory to them in order to ascertain how users implement this requirement. All administrative queries should be directed to the DEP Administrator in Shell GSI.

3 Page 3 TABLE OF CONTENTS INTRODUCTION TO INFORMATIVE... 4 INFORMATION PERTAINING TO COMPANION DEP Gen INTRODUCTION SCOPE VALVE CRITICALITY ANALYSIS VALVE CRITICALITY RATING REFERENCES... 11

4 Page 4 INTRODUCTION TO INFORMATIVE This new DEP Informative is the companion to DEP Gen Specification, and provides the rationale for certain requirements and recommendations in that document. For clarity, the section and paragraph numbering of DEP Gen. is used in this document. Where there are no comments regarding a particular paragraph or section, these have been omitted. The information in this document is maintained by the custodian responsible for the DEP, primarily for the following purposes: Documentation of the reason or background for certain requirements, particularly where those requirements have raised questions in the past; Inclusion of a PS Table, if applicable, to explain the reasons and give the risk ratings for requirements if they have been designated as process safety related. This information can be used as guidance when considering deviation requests.

5 Page 5 INFORMATION PERTAINING TO COMPANION DEP Gen. 1. INTRODUCTION 1.1 SCOPE This DEP is intended for use during a project s DEFINE phase, and is followed up in the EXECUTE phase, in conjunction with the overall approach outlined in DEP Gen., where it is best executed as part of the HFE Design Analysis. NOTE: The term ergonomics is used by many organisations and can be considered synonymous with Human Factors Engineering. This DEP should be read in conjunction with the following Shell standards in so far as they cover additional aspects of valves: Human Factors Engineering in Projects Human Factors Engineering Design and Procurement of Skid-Packaged Units Human factors Engineering Workspace Design Standard Form Human Factors Engineering Valve criticality ratings Plant Model Construction and Review Piping - General Requirements Instruments for Measurement and Control Structural design and engineering Onshore Steel Structures Onshore Ancillary Steel Structures Structural Design of Platform Decks, Steel Skids and Misc. Structural Steel Items Revision 2.0 DEP Gen. DEP Gen. DEP Gen. DEP Gen. DEP Gen.: DEP Gen DEP Gen.: DEP Gen DEP Gen DEP Gen. ENG0068SP

6 Page 6 3. VALVE CRITICALITY ANALYSIS The aim of this procedure is to ensure that all valve configurations are well designed for the purposes of operational and maintenance task performance. This is achieved by ensuring that the ease and efficiency of use of valves identified as being most critical, as well as the risk of injury associated with operating them, are not comprised by competing considerations in the designing and laying out of the facility. The potential benefits from the proper application of this procedure include: In Design: Reduced engineering hours (less re-work) thanks to earlier and more explicit communications between Principal and Contractor on expectations regarding HFE and general operability; More efficient approval cycle through application of an early and right first time approach; More efficient and focused design and/or model reviews (2D and/or 3D CAD) with better traceability of design requirements and trade-offs; Potential reductions in CAPEX through reduction of (permanent) steel structures as a result of a tighter categorisation of Category-1 (Critical) valves. In Operations: Improved ease and efficiency of working on the part of the Principal s personnel (i.e. end users in Operations); Reduced OPEX through reduced avoidance of modification costs to mitigate health risks; Improved emergency response through quicker and more accurate identification, access, operation and status feedback of valves; Fewer health problems (e.g. muscular-skeletal strain) due to operators having to adopt awkward postures or require forces to be exerted that exceed their capabilities. Key steps in the process The early identification and classification of valves (and defining the associated design location criteria for workspace design and layout) is the first key step in the process of delivering effective HFE workspaces in terms of valve identification, operation, inspection and maintenance (i.e. ensuring that the design complies with the needs of the end user). It allows awareness to be raised, critical valves to be identified and relevant steps to be taken to ensure that the selection, location and layout of valves and actuators support operational requirements. The second key step is to ensure that HFE requirements are implemented and maintained throughout the remaining detail design and construction phases, and that any additional valve types are properly identified and categorised. Important actions for checking and assuring compliance with HFE requirements include: Assurance of HFE competence and awareness within the Project Team. The Engineering Contractor s discipline engineer and/or lead piping designer shall raise any problems or deviation requests affecting valve selection, location and layout with the Principal (HFE Co-ordinator with support from HFE Specialist as appropriate). Operations shall always be consulted. Auxiliary systems and Vendor-supplied package units (skids) merit special attention in this phase. Formal checks during model reviews. A construction-phase HFE assurance plan to ensure that the requirements of this DEP and other (non valve related) HFE design requirements are not inadvertently compromised during construction.

7 Page 7 The third key step takes place in the operational phase of the project, when a valves audit should be undertaken to ensure that adequate steps have been taken to assure the operational purpose of each valve. Safe systems of work for tasks requiring valve operation should have been devised, and measures taken to ensure that non-operational valves are, if appropriate, adequately protected from being operated by operators. For example, a hot tap valve that shall not be used under normal operations should be protected to ensure that it cannot be operated (e.g. removal of the valve handwheel if it is appropriate and safe to do so). In addition, the correct procedures for all tasks shall be clearly communicated. Process description Figure 1 indicates the steps typically required. 1 VCA Required? No Stop Yes PEFS (P&IDs) 2 Arrange VCA Session VCA Session 3 Review Valve Classification and Determine Criticality Rating 4 Consider Use of MOV, RVO & Mobile Actuators 5 Formalize requirements and integrate in BDP/BDEP/PS 6 Validate compliance throughout EXECUTE Phase Figure 1 Flow scheme of activities for Valve Criticality Analysis (VCA)

8 Page 8 Steps in Figure 1: 1. HFE Screening - VCA requested? The typical point at which a VCA is requested is during the HFE Screening session (Project Team meeting to discuss HFE scope of work required). The VCA can efficiently be conducted as part of an HFE Design Analysis activity, or alternatively as a standalone work scope (see DEP Gen.). For skid-packaged units, the decision to conduct a VCA for a particular unit will be dependent upon the outcome of the HFE skid-package screening as described in DEP Gen. Valves on skid-packaged units shall comply with the HFE design requirements provided in Section 4 of the Specification, whether a VCA was requested or not. 2. Arrange and execute VCA session. As soon as the PEFS (P&IDs) are available, the HFE Co-ordinator or Operations representative in the Project Team arranges the session. On "minor" projects or where an Operations representative has not yet been assigned to the project, the Piping and Layout discipline or group may have to arrange the VCA session. At least the following disciplines shall be represented at the VCA session as a minimum: Operations; Maintenance; Piping and Layout. For complex projects the following additional disciplines should also be considered: Human Factors Engineering; Process Engineering; Technical Safety; Civil/Structural. For Vendor-supplied skid-packaged units that were identified requiring a VCA, the Package Engineer will have responsibility for arranging the session, in consultation with the HFE TA or Operations representative. 3. Prepare valve list and determine criticality ranking The VCA session shall prepare a listing or table of valve types identified on the PEFS (P&IDS) and review the valve criticality criteria provided in the companion Specification. It may be necessary to modify the valve criticality criteria provided in the companion Specification due to regional or site specific requirements, e.g. extreme weather conditions that prevent the use of auxiliary access equipment, thus resulting in permanent access being required. The VCA session shall then determine and record the valve criticality rating for all the valve types listed, utilizing the categories and classification criteria as agreed upon in the session. 4. Consider use of MOV, RVO and Mobile Actuator After determining the valve criticality categories or ratings for all valves, any additional valves requiring actuators (motorised or mobile) or remote operators shall be identified and a method of operation selected on the basis of process engineering, economic and HFE criteria (e.g. frequency and duration of operation, force required, speed of activation required, etc). Guidelines for the selection of actuators for non-control valves are provided in Section 4 of the Specification. NOTE: Depending on the availability of information on valve details and specific process conditions at the time of the VCA session, this step may have to be postponed or reviewed during detailed engineering as more information becomes available. Additional valves, requiring actuators, should also be considered during HAZOP studies.

9 Page 9 5. Formalize requirements After completion of the VCA session the results shall be appropriately documented. The associated access and location requirements for each valve type shall be included in the BDP/BDEP/Project Specification and managed by the Piping and Layout discipline or group. Deviation from the Project Specification requires the approval of Operations and HFE TA. Criticality ratings of valves shall be included on PEFS (P&IDs), and if a 3D CAD model is being used for design, Category 1 valves shall be coded therein (e.g. by colour coding 3D shapes). 6. Validate compliance Validate compliance throughout the EXECUTE (Engineering, Procurement and Construction) Phase as well as pre-start-up audits and update VCA results and the associated access and location requirements as necessary during design.

10 Page VALVE CRITICALITY RATING To facilitate the valve criticality rating process, two examples of valve listings and criticality ratings are provided. Table 1 shows the parameters to be considered when rating valve criticalities and shows a few examples of assigned ratings. Standard Form DEP Gen. provides a complete listing for the valves considered so far and will probably be updated with more valve types when further experience has been gained. Individual projects may also have to apply some cultural calibration for a specific user population or geographical region or adjust the information in Standard Form DEP Gen. for a specific project or installation/facility. When utilizing Standard Form DEP Gen., the VCA session should determine whether all the appropriate valve types depicted in the PEFS (P&IDs) are listed and add/delete some if necessary rating the valve criticality of each valve type. Once agreement is reached, the criticality category (C-1, C-2 or C-3) shall be recorded and the associated access and location requirements for each valve type shall be included in the BDP/BDEP/Project Specification. Criticality ratings of valves shall be included on PEFS (P&IDs), and if a 3D CAD model is being used for design, Category-1 valves shall be coded therein (e.g. by colour coding 3D shapes). Table 1 Examples of valve criticality analysis and ratings No. Valve type Process Control Essential Safeguarding High likelihood of failure Serious consequence of failure Frequent operation or maintenance Criticality rating 1. Valves associated with columns/vessels 1.1 Manual In/out isolation valves C Open vent valve (high point vents) C Open drain/utility connection valve (low point) C Closed drain valve C Bypass on isolation valve C Skimming valves (interface bleed valve) Yes Yes C-1 2 Valves associated with tanks 2.1 Manual In/out isolation valves Yes C Bottom open drain valve Yes C Pressure vacuum valves Yes C Potable or de-mineralized water connection to inlet/outlet line C-2 3 Valves associated with exchangers 3.1 Manual In/out isolation valves C-2 etc., etc., etc., etc., etc., etc., etc., etc., etc., etc., See Standard Forms Design Books for a complete listing

11 Page 11 REFERENCES In this DEP, reference is made to the following publications: NOTES: 1. Unless specifically designated by date, the latest edition of each publication shall be used, together with any amendments/supplements/revisions thereto. 2. The DEPs and most referenced external standards are available to Shell staff on the SWW (Shell Wide Web) at SHELL STANDARDS Human Factors Engineering in Projects Human Factors Engineering Design and Procurement of Skid- Packaged Units Human Factors Engineering Design for process safety critical tasks Human Factors Engineering Workspace Design Standard Form Human Factors Engineering Valve criticality analysis Plant Model Construction and Review Piping General Requirements Instruments for Measurement and Control Structural design and engineering of onshore structures Onshore steel structures Onshore Ancillary Steel Structures Structural Design of Platform Decks, Steel Skids and Misc. Structural Steel Items Revision 2.0 DEP Gen. DEP Gen. DEP Gen. DEP Gen. DEP Gen. DEP Gen.: DEP Gen. DEP Gen. DEP Gen DEP Gen DEP Gen. ENG0068SP