Lesson 25 IACS Repair Quality Standard for Existing Ships Part II.

Lesson 25 IACS Repair Quality Standard for Existing ShipsPart II

CONTENTS

1. Welding requirement

2. Repair quality standard

3. Doublers on plating

4. Renewal of internals/stiffeners

5. Renewal of internals/stiffeners -

transitions inverted angle/bulb profile

1. Welding Requirement

A. Correlation of welding consumables with

hull structural steels

B. General requirements to preheating and

drying out

C. Dry welding on hull plating below the

waterline of vessels afloat

Repair quality standardItem Standard Limit Remarks

Material Grade Same as original or higher See Section 4

Welding Consumables IACS UR-W17 (ref. 6) Approval according. to equivalent international standard

Groove / roughness See note and Fig. 22.1 d < Grind smooth

Pre-Heating See Table 22.1 Steel temperature not lower than

Welding with water on the outside See Section 5.3 Acceptable for normal and high strength steels

Moisture to be removed by a heating torch

Alignment As for new construction

Weld finish IACS guide for inspection of ship hull welds (ref. 10)

NDE IACS guide (ref. 10) At random with extent to be agreed with attending surveyors

NOTE: Slag, grease, loose mill scale, rust and paint, other than primer, to be removed.

Doublers on plating

Doublers on plating

Renewal of internals/stiffeners

Item Standard Limit Remarks

Size insert Min. Min.

Material grade Same as original or higher See Section 4.

Edge Preparation As for new construction. Fillet weld stiffener web/plate to be released over min. d =

Welding sequence See fig.22.4 . Weld sequence is 1→ 2 → 3

Alignment As for new construction

Weld finish IACS guide for inspection of ship hull welds (ref. 10)

NDE IACS guide (ref. 10)

Renewal of internals/stiffeners - transitions inverted angle/bulb profile

Termination of straps

WORDS Ambient adj. 周围环境 Submerge v. 浸没 hydrogen n. 氢 alignment n. 找中、队中 compliance n. 符合 Insert n. 嵌补板 Pitch n. 波高 circumferencial adj. 圆周的 throat n. 焊喉 Internals n. (pl)内部构件 Transition n. 过渡 Taper v. 逐渐变细 /薄 Strap n. 带钢 Asymmetrical adj. 不对称的

Phrases and Expressions ambient temperature 环境温度 submerged arc welding 埋弧焊 coated low-hydrogen electrode 碱氢焊条 manual metal arc welding 手工电弧焊 grind smooth 研磨平整 weld finish 焊缝处理 as for new construction 如同新结构（建造）

at random 随机（选择） rounded off corner 倒圆角 edge preparation (焊接 )接边加工 slot welding 槽焊 (长孔焊 ) step welding 分段焊接 fillet weld 角焊

Assignment

1. Review the text.

2. Do the exercises on Page 249.