Упражнения

Упр.1. Найдите в тексте английские эквиваленты следующих слов и словосочетаний:

1. Сложная конфигурация; 2. проводить испытания на усталость металла; 3. укрепление; 4. рассчитывать напряжения; 5. допустимое смещение; 6. концентрация напряжений; 7. эксплуатация судна; 8. проявление усталости металла; 9. удлинить швы; 10. в отношении чего-либо, для … .

Упр.2. Переведите на английский язык следующие слова и словосочетания:

1.Alternate stresses; 2. design; 3. construction; 4. scantlings; 5. to specify requirements; 6. hot spots; 7. hot spots stress range; 8. manufacturing process; 9. undercut; 10. survey requirements.

Unit 43. WELD TESTING

The following requirements determine the testing conditions for gravity tanks, including independent tanks of 5 m3 or more in capacity, watertight or weather-tight structures. The purpose of these tests is to check the tightness and/or

the strength of structural elements. Tests are to be carried out in the presence of the Surveyor at a stage sufficiently close to completion so that any subsequent work would not impair the strength and tightness of the structure.

IR InI particular, tests are to be carried out after air vents and sounding pipes are fitted. The Society may accept that structural testing of a sister ship is limited to a single tank for each type of structural arrangement. However, if the Surveyor detects anomalies, he may require the number of tests to be increased or the same number of tests to be provided as for the first ship in a series.

Shop primer is a thin coating applied after surface preparation and prior to fabrication as a protection against corrosion during fabrication. Protective coating is a final coating protecting the structure from corrosion. Structural testing is a hydrostatic test carried out to demonstrate the tightness of the tanks and the structural adequacy of the design. Where practical limitations prevail, and hydrostatic testing is not feasible (for example, when it is difficult, in practice, to apply the required head at the top of the tank), hydro-pneumatic testing may be carried out instead. Hydro-pneumatic testing is a combination of hydrostatic and air testing, consisting in filling the tank to the top with water and applying an additional air pressure. Leak testing is an air or other medium test carried out to demonstrate the tightness of the structure. Hose testing is carried out to demonstrate the tightness of structural items not subjected to hydrostatic or leak testing and of other components which contribute to the watertight or weather-tight integrity of the hull.

A sister ship is a ship having the same main dimensions, general arrangement, capacity plan and structural design as those of the first ship in a series.

Structural testing may be carried out before or after launching, after application of the shop primer or of the protective coating, provided that one of the following two conditions is satisfied: 1. all the welds are completed and carefully inspected visually to the satisfaction of the Surveyor prior to the application of the protective coating and 2. leak testing is carried out prior to the application of the protective coating . In the absence of leak testing, protective coating is to be applied after the structural testing of all erection welds, both manual and automatic, i all manual fillet weld connections on tank boundaries and manual penetration welds.

When hydro-pneumatic testing is performed, the conditions are to simulate, as far as practicable, the actual loading of the tank. The value of the additional air pressure is at the discretion of the Society, but it is to be at least as defined for leak testing. The same safety precautions as for leak testing are to be adopted.

An efficient indicating liquid, such as a soapy water solution, is to be applied to the welds. Where leak testing is carried out, an air pressure of 0,15.105 Pa is to be applied during t the test. Prior to inspection it is recommended that the air e pressure in the tank should be raised to 0,2.105 Pa and kept at this level for approximately 1 hour to reach a stabilized state, with a minimum number of personnel in the vicinity of the tank, and then lowered to the test pressure. The test may be conducted after the pressure has reached a stabilized state at 0,2.105 Pa, without lowering the pressure provided the Society is satisfied of the safety of the personnel involved in the test. A U-tube filled with water up to a height corresponding to the test pressure is to be fitted to avoid overpressure of the compartment tested and to verify the test pressure. 14.2.2 / RINA B-I, 23.1.2 / BV 3.042.,

The U-tube is to have a cross-section larger than that of the pipe supplying air. In addition, the test pressure is also to be verified by means of one master pressure gauge. Alternative means which are considered to be equivalently reliable may be accepted at the discretion of the Surveyor.

Leak testing is to be carried out, prior to the application of a protective coating, on all fillet weld connections on tank boundaries, and penetration and erection welds on tank boundaries excepting welds made by automatic processes.

Selected locations of automatic erection welds and pre-erection manual or automatic welds may be required to be similarly tested to the satisfaction of the Surveyor, taking account of the quality control procedures operating in the shipyard.

When hose testing is required to verify the tightness of the structures, the minimum pressure in the hose, at least equal to 2,0.105 Pa, is to be applied at a maximum distance of 1,5 m. The nozzle diameter is to be not less than 12 mm. Other testing methods may be accepted, at the discretion of the Society, based upon equivalency considerations.

VOCABULARY

Water-tight – герметичный, водонепроницаемый

Weather tight – погодостойкий, защищающий от атмосферного воздействия

Capacity – вместимость, грузоподъемность

air vent – воздуховод, вентиляционное отверстие

sounding pipe –трубка эхолота

sister ship – однотипное судно

gravity tank – бак подачи топлива самотеком

erection weld – монтажный шов

at the discretion of – на усмотрение …

leak testing – испытание на герметичность

master pressure gauge – главный манометр

hose testing - испытание наливом