DIMENSION-CONTROL-PROCEDURE(英文).doc

1.0 INTRODUCTION1.1 This surveying procedure details the techniques and methods used to accurately measure and report the dimensional statues of the CHX module fabrication.1.2 Dimensional control shall be performed by both QC and fabrication department.1.3 The fabrication department shall ensure that the survey requests are submitted at required site. The dimensional control section shall work closely with the fabrication department at all sites of fabrication.1.4 Client shall be informed in advance of dimensional control activities.2.0 EQUIPMENT AND STANDARDS2.1 The dimensional control section shall use suitable dimensional measuring equipment. All instrument used shall have current calibration certificate. (See the APPENDIX 1 INVENTORY OF EQUIPMENT)2.2 Reference standards shall be the Clients specification ST-SP-101 and Clients drawings and any relevant standards applicable within this specification for module structure fabrication.3.0 GENERAL DIMENSIONAL CONTROL OF MODULE 3.1 Tubular splicingControl the straightness at the oo and 90o directions of spliced tubes. Measurement shall be accomplished by use a taut wire stretched from end to end of the length being measured and the measurement made at the point of greatest deviation. The dimensional report shall be provided to Client and Certifying Authority.3.3 MODULE GENERAL DIMENSION CONTROL 3.3.1 Set out the position of all column supports and column center lines and checking level of column supports. 3.3.2 Perform survey of ROW2 frame before welding and after welding prior to roll-up, mark the survey point clearly on the surface of the column and check the level、distance of adjacent column and diagonal distance, provide the dimension reports to Client and Certification Authority. 3.3.3 Perform survey of each pre-fabricated deck frame before welding and after welding, including the diagonal and the width、length of the deck frame. The deck frame including: 3.3.4 After ROW2 roll-up, use the theodolite check its correct position and level at two-direction interval 90 degree. 3.3.5 Survey the adjacent distance , diagonal distance and alignment of the column bottom. 3.3.6 As each of the frame are fitted a survey shall be performed to check its position relative to other structure, once all the members are fully welded that the final survey of the entire structure shall commence, including : (1) The level of the main deck;(2) The adjacent distance and diagonal distance of the column center line at the top and bottom of column. For survey the dimension of column at EL(+)22400, we mark survey points on row 1、row 2 axis in the same direction. Each point distance 100mm from the column outside wall. (3) Check the crane pedestal inclination before welding and after welding. The survey reports shall provide to the Client and Certification Authority. 4.0TECHNICAL REQUIREMENTS 4.1The horizontal distance deviation between any two adjacent jacket legs or non-adjacent legs shall be less than or equal to 10mm of the dimensions shown on the Contract Drawings .The diagonals dimension relative deviation in any plan shall be less than or equal to 19mm. 4.2 The vertical distance between jacket levels shall be within 13mm of the dimension shown on the Contract Drawings. 4.3 Overall and individual structural dimensions shall be within 10mm of the dimensions shown on the Contract Drawings.4.4 Local of changes in pile wall thickness shall be within 150mm of the locations indicated on the Contract Drawings. Overall length of piling shall be within 150mm of the length shown on the Contract Drawings.4.5 The relative local of the leg sections with different wall sections shall be within 25mm of the locations indicated on the Contract Drawings. 4.6 The straightness of spliced members shall not deviate from a straight line by more than 3mm in any 3m length nor by more than 10mm in any length of 12m or more.4.7 Horizontal alignment of jacket legs during fabrication shall be maintained within 6mm.4.8 The overall dimension of the jacket between top and bottom bracing levels shall be within 25mm of the dimension shown on the Contract Drawings.4.9 The center of the top and bottom of all conductor guides and supports shall not deviate by more than 10mm from the true theoretical position of the straight line defined on the Contract Drawings. 4.10 The distance deviation between any two adjacent module deck leg column shall be less than or equal to 10mm.; the diagonals distance deviation in any plan shall be less than or equal to 19mm. 4.11 Deck plate and grating floors shall be plane within a tolerance of L/200 of the smallest panel dimension or 6mm,which is smaller. Floors and roofs elsewhere shall be plane within a tolerance of L/200 of the smallest panel dimension or 10mm, which is smaller. At joint ,the difference in level between adjacent areas shall be