EN 1090-2 Standardı

EN 1090-2 EXC 3 maddeleri nelerdir?

Sanayide EN1090 standardına göre imalat yapan bir çok üretici standardın EXC3 kapsamında çalışmaktadır.

EXC3'ün özellikle EXC2 ve EXC4 ile aynı ve farklı yönlerini bilmek standarda göre iş yaparken oldukça önemlidir.

Standart maddeleri içinde EXC3 geçen bölümlar şunlardır:

4 Specifications and documentation

4.2 Constructor's documentation

4.2.1 Quality documentation

The following points shall be documented for EXC2, EXC3 and EXC4:

a) the allocation of tasks and authority during the various phases of the project;

b) the procedures, methods and work instructions to be applied;

c) an inspection plan specific to the works;

d) a procedure for handling changes and modifications;

e) a procedure for handling of nonconformities, requests for concessions and quality disputes;

f) any hold points or requirement to witness inspections or tests, and any consequent access requirements.

5 Constituent products

5.2 Identification, inspection documents and traceability

For structural steel grade S355 JR or J0 inspection document 3.1 is required for EXC2, EXC3 and EXC4.

For EXC3 and EXC4, constituent products shall be traceable at all stages from receipt to hand over after incorporation in the works.

For EXC2, EXC3 and EXC4, if differing grades and/or qualities of constituent products are in circulation together, each item shall be designated with a mark that identifies its grade.

5.3 Structural steel products

5.3.3 Surface conditions

If more stringent surface conditions are required for plates in EXC3 and EXC4, they shall be specified.

5.3.4 Special properties

For EXC3 and EXC4, internal discontinuity quality class S1 of EN 10160 shall be specified for welded cruciform joints transmitting primary tensile stresses through the plate thickness on a band of width four times the thickness of the plate each side of the proposed attachment.

6 Preparation and assembly

6.2 Identification

At all stages of manufacturing each piece or package of similar pieces of steel components shall be identifiable by a suitable system. For EXC3 and EXC4 finished components shall be identified to inspection certificates.

6.4 Cutting

6.4.3 Thermal cutting

Table 9 — Quality of the cut surfaces

Perpendicularity or angularity tolerance, u Mean height of the profile, Rz5 EXC3 Range 4 Range 4

6.5 Shaping

6.5.3 Flame straightening

For EXC3 and EXC4 a suitable procedure shall be developed. The procedure shall include at least:

a) maximum steel temperature and procedure of cooling allowed;

b) method of heating;

c) method used for temperature measurements;

d) results of mechanical tests carried out for the process approval;

e) identification of workers entitled to apply the process.

6.6 Holing

6.6.3 Execution of holing

For EXC3 and EXC4, punching without reaming is not permitted. The holes shall be punched at least 2 mm undersize in diameter.

6.7 Cut outs

Re-entrant corners and notches shall be rounded off with a minimum radius of: 5 mm for EXC2 and EXC3.

6.9 Assembly

Drifting to align holes shall be carried out in such a way that the elongation does not exceed the values given in D.2.8 No 6 as follows:

EXC3 and EXC4: Class 2.

7 Welding

According to the execution class, the following parts of EN ISO 3834 apply:

EXC3 and EXC4: Part 2 "Comprehensive quality requirements".

7.4 Qualification of welding procedures and welding personnel

7.4.1 Qualification of welding procedures

7.4.1.3 Qualification of welding procedures for other welding processes

For EXC2, welding procedure qualification based on previous experience is permitted. For EXC3 and EXC4, welding procedure qualification shall be carried out by welding procedure test or pre-production test.

7.4.3 Welding coordination

For EXC2, EXC3 and EXC4, welding coordination shall be maintained during the execution of welding by welding coordination personnel suitably qualified for, and experienced in the welding operations they supervise as specified in EN ISO 14731.

7.5 Preparation and execution of welding

7.5.1 Joint preparation

Prefabrication primers (shop primers) may be left on the fusion faces only if they do not adversely affect the welding process. For EXC3 and EXC4, prefabrication primers shall not be left on the fusion faces, unless welding procedure tests in accordance with EN ISO 15614-1 or EN ISO 15613 have been completed using such prefabrication primers.

7.5.6 Temporary attachments

The use of temporary attachments for EXC3 and EXC4 shall be specified.

If temporary welded attachments have to be removed by cutting or chipping, the surface of the parent metal shall subsequently be carefully ground smooth. Cutting and chipping are not permitted for EXC3 and EXC4, unless otherwise specified. Adequate inspection shall be carried out to ensure that the constituent product is not cracked on the surface at the temporary weld location.

7.5.9 Butt welds

For EXC3 and EXC4, and for EXC2 if specified, run-on/run-off pieces shall be used to ensure full throat thickness at the edge. The weldability of such run-on/run-off pieces shall not be less than that of the parent metal.

7.5.9.2 Single sided welds

Backing materials shall be fitted tightly to the parent metal and should generally be continuous for the full length of the joint. For EXC3 and EXC4, permanent backing metal shall be made continuous by means of full penetration butt welds. Tack welds shall be included in the butt welds.

7.5.17 Execution of welding

Precautions shall be taken to avoid weld spatter. For EXC3 and EXC4, it shall be removed.

7.6 Acceptance criteria

The acceptance criteria for weld imperfections shall be as follows, with reference to EN ISO 5817, except "Incorrect toe" (505) and "Micro lack of fusion" (401) which are not to be taken into account. Any additional requirements specified for weld geometry and profile shall be taken into account. EXC3 quality level B;

9 Erection

9.6 Erection and work at site

9.6.3 Handling and storage on site

The procedure for restoration shall be defined before undertaking the repair. For EXC2, EXC 3 and EXC 4 the procedure shall also be documented.

9.6.5 Erection methods

9.6.5.3 Fit-up and alignment

Alignment of the structure and lack of fit in connections may be adjusted by the use of shims. Shims shall be secured where they are in danger of coming loose. For EXC3 and EXC4 securing of shims by welding is subjected to the requirements of Clause 7.

12 Inspection, testing and correction

12.4 Welding

12.4.2 Inspection after welding

12.4.2.2 Scope of inspection

Unless otherwise specified no supplementary NDT is required for EXC1 welds. For EXC2, EXC3 and EXC4 welds the extent of supplementary NDT is as specified below.

The extent of NDT covers both testing of surface or internal imperfections if applicable.

For the first 5 joints made to the same new WPS the following requirements shall be fulfilled:

a) the quality level B is required for demonstration of the WPS in production conditions;

b) the % to be tested shall be double of the values in Table 24 (max. 100 %);

c) the minimum length to be inspected is 900 mm.

12.4.2.5 Correction of welds

For EXC2, EXC3 and EXC4, repairs by welding shall be carried out in accordance with qualified welding procedures. Corrected welds shall be checked and shall meet the requirements of the original welds.

12.4.4 Production tests on welding

If specified, for EXC3 and EXC4, production tests shall be carried out as follows:

a) each welding procedure qualification used for welding steel grades higher than S460 shall be checked with a production weld. Testing includes visual examination, penetrant testing or magnetic particle inspection, ultrasonic testing or radiographic testing (for butt welds), hardness testing and macroscopic examination. The tests and results shall be in accordance with the relevant standard for welding procedure test;

b) if the deep penetration of a welding process is used for fillet welds, the penetration of the welds shall be checked. The results of the actual penetration shall be documented;

c) for bridge deck orthotropic steel plates:

1) stiffener to deckplate connections welded by fully mechanized welding process shall be checked with a production test for each 120 m length of bridge, with a minimum of one production test for a bridge, and inspected by macro-examination. Macro section tests shall be prepared at start or stop and at the middle of the weld;

2) stiffener to stiffener connections with splice plates shall be checked with a production test.

12.5 Mechanical fastening

12.5.2 Inspection and testing of preloaded bolted connections

12.5.2.2 Inspection before tightening

For EXC2, EXC3 and EXC4, the tightening procedure shall be checked. If tightening is carried out by the torque method or the combined method, the torque wrench calibration certificates shall be checked to verify the accuracy to 8.5.1.

12.5.2.3 Inspection during and after tightening

For EXC2, EXC3 and EXC4, inspection during and after tightening shall be carried out as follows:

a) inspection of installed fasteners and/or methods of installation shall be undertaken depending on the tightening method used. The locations selected shall be on a random basis ensuring that the sampling covers the following variables as appropriate - connection type; bolt group, fastener lot, type and size;

equipment used and the operatives;

b) for the purposes of the inspection, a bolt group is defined as bolt assemblies of the same origin in similar connections with the bolt assemblies of the same size and class. A large bolt group may be subdivided into a number of subgroups for inspection purposes;

c) the number of bolt assemblies inspected overall in a structure shall be as follows:

EXC3 and EXC4:

i. 5 % for the first step and 10% for the second step of the combined method;

ii. 10 % for the second step of the torque method and for the DTI method;

d) unless otherwise specified, the inspection shall be carried out using a sequential sampling plan according to Annex M for a sufficient number of bolt assemblies until either the acceptance or the rejection conditions (or all assemblies have been tested) for the relevant sequential type are met for the relevant criteria. The sequential types shall be as follows:

EXC2 and EXC3: sequential type A;

e) the pretightening step shall be checked by visual inspection of connections to ensure they are fully packed;

f) for final tightening inspection the same bolt assembly shall be used for checking both under-tightening and, if specified, over-tightening;

g) for the inspection of pretightening only the under-tightening criterion is to be checked;

h) the criteria defining a nonconformity and requirements for corrective action are specified below for each tightening method;

i) if the inspection leads to a rejection, all the bolting assemblies in the bolt subgroup shall be checked and corrective actions shall be taken. If the result of inspection when using a sequential type A is negative, the inspection may be enlarged to the sequential type B;

j) after completion a new inspection is required. If fasteners are not applied in accordance with the defined method, the removal and re-installation of the

whole bolt group shall be witnessed.

12.5.2.5 Combined method

For EXC3 and EXC4 the first step shall be controlled before marking using the same torque conditions as used to reach the 75 % condition. A bolt which turns by more than 15° by the application of the inspecting torque is considered defective and shall be retightened.

12.5.3 Inspection, testing and repairs of hot rivets

12.5.3.1 Inspection

Inspection of satisfactory contact shall de done by lightly ringing the rivet head with a hammer of 0,5 kg. The inspection is carried out using a sequential sampling plan according to Annex M to a sufficient number of rivets until either the acceptance or the rejection conditions for the relevant sequential type are met for the relevant criteria. The sequential types are as follows:

EXC2 and EXC3: sequential type A;

If the inspection leads to a rejection, all the rivets shall be checked and corrective actions shall be taken.

12.7 Erection

12.7.3 Survey of geometrical position of connection nodes

12.7.3.1 Survey methods and accuracy

A survey of the completed structure shall be made. This survey shall be related to the secondary net. For EXC3 and EXC4 this survey shall be recorded; if there is a requirement to record dimensional checks at acceptance of the structure, this shall be specified.

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