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Section 8 Special Cast Iron Valves
801. Application
The requirements in this Section apply to the tests and inspection for the approval of manufacturing process of special cast iron valves (black heart malleable castings and spheroidal graphite iron cast- ings which has elongation of 12 % or above) specified in Pt 5, Ch 5, 102. 4. of the Rules.
802. Approval tests
Approval tests specified in Table 2.8.1 are to be carried out to verify the material quality of spe- cial cast iron in the presence of the Surveyor. Tensile test and charpy impact test are to be carried
out on the test specimens separately cast and on those taken from the valve body of size.
the
largest
Table 2.8.1 Approval Testing Method and Acceptance Criteria for special cast iron valves
Kinds | Test item | Test method | Acceptance criteria |
Spheroidal graphite iron cast- ings | Tensile test | The separately cast test sample is to be of A type specified in KS D 4302. Tensile test is to be carried out on two test specimens taken from test sample at room temperature (in case of boiler mounting valves, at each temperature of 200°C, 300°C and 400°C). Two test specimens (R 14A type specified in Table 2.1.1 of Pt 2, Ch 1 of the Rules) for ten- sile test at room temperature are to be taken from the valve body. (the separately cast test sample is to be heat treated as same as applied to the valve body.) | To comply with the Rule requirements |
Charpy impact test | Three each test specimens of R 4 type specified in Table 2.1.3 of Pt 2, Ch 1 of the Rules are to be taken from test sample and flange of valve body. | To comply with the Rule requirements | |
Hardness test | Valve body is to be cut and hardness at each position is to be measured (Brinnel Hardness Test, 3000 kg). | To comply with the Rule requirements | |
Micro-structure analysis | Structural ferritization and spheroidization of graphite are to be examined. | To be as deemed appropriate by the Society | |
chemical com- position | For the analysis of total carbon, a drilling machine is not to be used. | To comply with the Rule requirements | |
Blackheart malleable iron cast- ings | Tensile test | Test specimen is to be of A type specified in KS D ISO 5922 and shall not be separately casted or machined unless approved by the Society. Two each test specimens are to be subjected to tensile test under the same temperature con- ditions as in Spheroidal graphite iron castings. The tensile test on the test specimens taken from valve body is to be as specified in Spheroidal graphite iron castings. | To comply with the Rule requirements |
Charpy impact test | The same as in Spheroidal graphite iron castings | To comply with the Rule requirements | |
Hardness test | The same as in Spheroidal graphite iron castings | To comply with the Rule requirements | |
Micro-structure analysis | Examination is to be carried out on the matrix and graphiti- zation, | To be as deemed appropriate by the Society | |
chemical com- position | The same as in Spheroidal graphite iron castings | To comply with the Rule requirements |
803. Dealings after approval
Special cast iron valves which conform to [in approval case] in the requirements in specified by the Society.
the requirements in this Section are to be dealt with as
Pt 2, Ch 1, 201. 2 (2) of the Rules, unless otherwise
36 Guidance for Approval of Manufacturing Process and Type Approval, Etc. 2015
Ch 2 Approval of Manufacturing Process Ch 2, Sec 9