GL认可规范

4.

Instruction/Procedure:

4.1

Range of Application

The present Regulations apply to the approval of manufacturers intending to

supply flash butt welded or upset butt welded anchor chain cables in accordance with

the Rules for Materials of Germanischer Lloyd (GL), and to the approval of the relevant

manufacturing processes. Application of these Regulations to lifting and lashing chains

may be agreed upon.

Regarding the approval of manufacturers of offshore mooring chains, the GL Rules

for Classification and Construction, IV – Offshore Technology, Part 6, Chapter 2,

Section 8, apply.

4.2

Application for Approval

Manufacturers intending to supply chain cables as per 4.1.1 above have to apply

for approval with GL in writing. In the application, the envisaged chain cable grades, the

corresponding steel grades/material specifications, manufacturing process of them

(rolled steels/forgings/cast steels), dimensions and cable supply conditions are to be

indicated. Also, it is to be stated whether cables will be manufactured with or without

studs.

4.3

Documentation

The application for approval is to be accompanied by documentation on

a) Organisation structure and quality assurance system.

b) Steel grades/material specifications for the envisaged chain cable grades, their

chemical composition and mechanical properties.

c) Description of bending/assembling facilities: type of furnaces for heating, method of

bending and bending temperature, heat treatment facilities, machining equipment.

d) Description of welding workshop: equipment, welding procedures, welding process

variables, control of welding parameters.

e) Studs: material, insertion method, welding procedure.

f) Heat treatment: temperature and chain speed for holding times, heating and cooling

rates, quenching and cooling medium after tempering.

g) Capacity and dimensions of the proof load testing machines. Copies of the last

calibration certificate of the proof load testing machines.

h) Testing facilities and equipment for the destructive and non-destructive testing and

dimension measurement, test personnels qualifications for non-destructive testings.

Laboratories for chemical and/or metallographic investigations.

i) Names and addresses for initial material (= prematerial) manufacturers where the mill

does not produce steel itself. The initial material manufacturers shall be approved by GL,

unless their prematerial is used for the manufacture of the products subjected to the

approval tests specified in para 4.5.

4.4

Works Inspection

During a workshop inspection proof is to be furnished to the GL Surveyor that the

facilities required for the proper manufacture and testing of the chain cables are

available. The manufacturing processes and the quality assurance system are to be

presented and explained to the Surveyor.

4.5

Approval Test 4.5.1.

Number of Test Specimens, Scope of Testing and Further Information to be

Submitted

Of each chain cable steel grade, of the largest dimensions two 3- and/or 5-link

test specimens each and at least 7 single links are to be presented and subjected to the

tests specified below:

a)

A complete chain cable length (approx. 27.5 m) is first subjected to 5 – 10 % of the proof

load on the test bench, and the length is to be measured. Then this chain cable length is

subjected to the proof load test.

Subsequently the test load is reduced to approx. 10 % and measurements are to be

carried out, determining the permanent total elongation, the length over 5 cable links as

well as the diameter, outside length and width of 3 links. The elongation must not exceed

5 %. The dimensions must be within the tolerance ranges indicated in the Rules for

Materials. The applied load and all measurements are to be reported.

After the proof load test the individual links of these specimens must be

capable of being moved within an angle of 180° against each other without

any difficulty.

b)

Breaking load test on a 3- or 5- links sample of the chain cable length subsequent to the

proof load test in a). Breaking load, appearance and location of the rupture are to be

reported.

c)

Bending test (crossweld) 120° on two individual links arranged in horizontal position. In

case of larger steel bar diameters a specimen with a semicircle cross sectional area may

be machined of the link with the welding in the middle of the specimen. Bending radius:

for K1 and K2 3x diameter (or thickness), for K3 5x diameter (or thickness).

d)

Tensile test on two round test specimens machined out of the link, one of them having

the weld seam in the middle, the other without seam; specimen form A or B according to