Section 4 Steel Tubes and Pipes

401. Steel tubes for boilers and heat exchangers

1. Application

(1) The

side ers,

requirements are mainly to apply to steel tubes intended for heat transfer at inside or out- of the tubes; for example, smoke tubes, water tubes, stay tubes, superheater tubes of boil- other tubes for high temperature heat exchangers, etc. (hereinafter referred to as "steel

tubes").

(2) Steel tubes other than those specified in (1) are to comply with the requirements in 101. 2.

2. Kinds

The steel tubes are classified as specified in Table 2.1.41.

Table 2.1.41 Kinds

3. Heat treatment

The heat treatment of steel tubes is to comply with the requirements given in Table 2.1.42.

Table 2.1.42 Heat treatment See Guidance

4. Chemical composition

The chemical composition of steel tubes is to comply with the requirements given in

2.1.43. See Guidance

Table

Table 2.1.43 Chemical Composition

5. Mechanical properties See Guidance

The mechanical properties of steel tubes are to comply with the following requirements.

(1) Tensile test : The tensile test of steel tubes

2.1.44.

is to comply with the requirements given in Table

Table 2.1.44 Mechanical Properties

(2) Flattening test : A tubular section which is taken from the end of the steel tube is to stand be- ing flattened cold between parallel plates, without cracking or showing flaw, until the distance between the plates becomes less than the value of H calculated by the following formula. In this case, the length L of steel tube is to be not less than 50 mm, however, not more than 100 mm. For electric-resistance welded steel tubes, however, the welded line is to be placed at

right angle to the direction of the applied force as shown in Fig 2.1.9 (a) For tubes, of 15 % of outside diameter and over in thickness, C-type test specimen may be used, part of its circumference discarded as shown in Fig 2.1.9 (b)

however, having a

where:

= Distance between flattening plates (mm). = Thickness of steel tube (mm).

= Outside diameter of steel tube (mm).

= Constant given in Table 2.1.45 which varies according to the grade of steel tubes.

Fig 2.1.9 Flattening test Table 2.1.45 Value of

(3) Flaring test : A section of steel tube which is taken from its end is to stand being flared cold with a tool having an included angle of 60 degrees, until the steel tube at the mouth of the flare is expanded without cracking or showing flaw to the diameter shown in Table 2.1.46. The rate of penetration of the mandrel shall not exceed 50 mm/min. In this case, the length of test specimen is to be 1.5 D , however, not less than 50 mm.

Table 2.1.46 Outside Diameter of Steel Tube End after Flaring

(4) Reverse flattening test : A section of steel tube of 100 mm in length which is taken from the steel tube is to be slotted longitudinally on the opposite side of the welded line, opened and flattened without cracking or showing flaw on the inside of the welded line. There is also to be no misalignment, lack of penetration and overlap. But, this test is applied for electric-resist- ance welded steel tubes only.

(5) Hydraulic test :

(a) Steel tubes are to be hydraulically tested to a satisfactory result by 2 times and over the

(b)

maximum working pressure at the mill. The test pressure prescribed in (a) need

formula:

But the minimum test pressure is to be 7 M P a.

not exceed the pressure calculated by the following

where:

= Thickness of steel tube (mm)

= Outside diameter of steel tube (mm)

= 60 of the prescribed minimum yield strength (N m m )

(c) Where each steel tube is hydraulically tested as a regular procedure during the process of manufacturing at the mill, which makes a number of steel tubes continually, and the results are forwarded to the Surveyor, the test in the presence of the Surveyor may be dispensed with.

(d) A non-destructive inspection deemed appropriate by the Society may be substituted for the hydraulic test specified in (a). See Guidance

6. Selection of test specimen See Guidance

The test specimens are to be taken in accordance with the following requirements, from each grade and each size which has been heat treated at the same time in the same heating furnace for heat- treated tubes and from each grade and each size for non-heat-treated steel tubes respectively.

(1) Seamless steel tubes

One sampling steel tube is to be selected from each lot of 50 tubes or fraction thereof and each one specimen for tensile test, flattening test and flaring test is to be taken from each sam- pling steel tube.

(2) Electric-resistance welded steel tubes

For electric-resistance welded steel tubes, in addition to the requirements in (1), one sampling steel tube is to be selected from each lot of 100 tubes or fraction thereof, and one reverse flat-

tening test specimen is to be taken from each of the sampling steel tubes.

7. Tolerance for dimensions

The tolerances for the outside diameter and thickness are to comply with the requirements in Table

2.1.47. and Table 2.1.48. respectively.

Table 2.1.47 Tolerance for Outside Diameter of steel Tubes

Table 2.1.48 Tolerance for thickness

8. Quality

(1) Each steel tubes are hydraulically or non-destructively tested as a regular procedure during the process of manufacturing at the mill and are free from leakages or harmful defects.

(2) The steel tubes are to be of uniform quality. For electric-resistance welded steel tubes, deposit

metal projected on outside of tubes is to be removed and finished smooth and that projected on inside of tubes is to be removed to have a height not more than 0.25 mm.

9. Retest procedures

Where the tensile test, flattening test, flaring test or reverse flattening test fails to meet the require- ments, additional tests may be conducted according to the requirements given in 109.

10. Marking

(1) The name or brand of the manufacturer, grade of tubes, size and symbol of the method of the manufacture relating to (2) below are to be legibly stamped or stenciled before shipment on each length steel tube in case of 30 mm and above in outside diameter and on each bundle or container of steel tubes in case of less than 30 mm in outside diameter. The Society"s brand indicating compliance with the requirements is to be stamped in the vicinity of the foregoing marks.

(2) The symbols indicating the method of manufacture are to be as specified in the following:

Hot finished seamless steel tube ············································································ Cold drawn seamless steel tube ············································································· Electric-resistance welded steel tube of other than hot and cold working ······ Electric-resistance welded steel tube of hot working ········································· Electric-resistance welded steel tube of cold working ·········································

-S-H

-S-C

-E -G

-E -H

-E -C

402. Steel pipes for pressure piping

1. Application

(1) These requirements are mainly to apply to steel pipes intended for use in piping which as "steel pipes").

(2) Steel pipes for general purpose specified in

seamless steel pipes and electric-resistance welded is prescribed in Pt 5, Ch 6 (hereinafter referred to

102. 2 (4) of Pt 5, Ch 6 are to comply with the

requirements of K S D 3507(SPP) or equivalent thereto. However, tests in the presence of the Surveyor are not required.

(3) The steel pipes having characteristics differing from those specified in 402. are to comply with

the requirements in 101. 2.

2. Kinds

The steel pipes are classified as specified in Table 2.1.49.

Table 2.1.49 Grades of Steel Pipes

3. Heat treatment

The heat treatment of steel pipes is to comply with the requirements given in Table 2.1.50.

Table 2.1.50 Heat treatment

4. Chemical composition

The chemical composition of steel pipes is to comply with the requirements given in Table 2.1.51.

Table 2.1.51 Chemical Composition

5. Mechanical properties

The mechanical properties of steel pipes are to comply with the following requirements.

(1) Tensile test : The tensile test of

2.1.52.

Table 2.1.52 Mechanical Properties

steel pipes are to comply with the requirements given in Table

(2) Flattening test

(a) Pipes other than Grade 1 of electric-resistance welded steel pipe: A tubular section of steel

pipe which is taken from the end of the steel pipe, is to stand being flattened between par- allel plates, without cracking or showing flaw, until the distance between the plates becomes

less than the value of H calculated by the following formula. In this case, the length of

test specimen is to comply with the requirements in 401.5 (2). For steel pipes, however, of 15 % of outside diameter and above in thickness, C-type test specimen may be used, having a part of its circumference discarded as shown in Fig 2.1.9 (b)

Table

where:

= Distance between flattening plates (mm). = Thickness of steel pipe (mm).

= Outside diameter of steel pipe (mm).

= Constant given in Table 2.1.53 which varies according tubes.

2.1.53 value of

to the grade of steel

(b) Electric-resistance welded steel pipes Grade 1 :

for welded line, for elsewhere.

In case of electric-resistance welded steel pipes, the welded line is to gle to the direction of the applied force, as in Fig 2.1.10.

be placed at right an-

Fig 2.1.10 Flattening test of electric-resistance welded steel pipes Grade 1

(3) Bend test : For steel pipes of 50 mm and

under in outside diameter, the specimen for flattening

test may be substituted for that for bend which is taken from the end of the steel

test. pipe

In this case, a test specimen of tubular section and has sufficient length is to stand being bent

cold, up to the specified value in Table 2.1.54, without cracking

But, for Grade 4, this test need not be carried out.

or showing flaw on the wall.

Table 2.1.54 Bend Test

(4) Hydraulic test

(a) Grade 1 steel pipes are to be hydraulically tested with the pressure specified in Table 2.1.55.

(b)

In case where the test pressure higher than prescribed in (a) is specified by the purchaser for Grade 2 through 4 steel pipes, the test is to be carried out with the specified pressure. In this case, test pressure need not exceed the pressure calculated by the following formula:

Mpa

where :

= Hydraulic test pressure (MPa).

= Outside diameter of steel pipe (mm). = Thickness of steel pipe (mm).

= 60 of the prescribed minimum yield strength (N m m ).

(c) When each steel pipe is hydraulically tested as a regular procedure during the process of manufacturing at the mill which makes a number of steel tubes continually, and the results are forwarded to the Surveyor, the test in the presence of the Surveyor may be dispensed with.

(d)

A non-destructive inspection deemed appropriate by the Society may be substituted for the hydraulic inspection specified in (a).

6. Selection of test specimen

(1) Grade 1 : Sampling steel pipes are to be selected as following requirements in connection with the nominal diameter of steel pipes specified in Table 2.1.55 and each one specimen for ten- sile test, flattening test or bend test is to be taken from each sampling steel pipe.

(a) For steel pipes less than 65A in nominal diameter : One sampling steel pipe is to be se- lected from each lot of 1000 pipes or fraction thereof.

(b)

(c)

(d)

For steel pipes which a nominal diameter is 65A or above and less than 150A : One sam-

pling steel pipe is to be selected from each lot of 500 pipes or fraction thereof.

For steel pipes which a nominal diameter is 150A or above and less than 350A : One sampling steel pipe is to be selected from each lot of 250 pipes or fraction thereof.

For steel pipes more than 350A in nominal diameter : One sampling steel pipe is to be se-

lected from each lot of 150 pipes or fraction thereof.

(2) Grade 2 : One sampling steel pipe is to be selected from each lot of 50 pipes or fraction thereof, and each one specimen for tensile test and flattening test or bend test is to be taken from each sampling steel pipe.

(3) Grade 3

Selection of test specimen is to comply with the requirements in (2).

(4) Grade 4 : One sampling steel pipe is to thereof, and each one specimen for tensile from each sampling steel pipe.

be selected from each lot of 50 pipes or fraction test and flattening test or bend test is to be taken

Table 2.1.55 Schedule and Hydraulic Test Pressure

7. Tolerance for dimensions

Tolerances for the outside diameter and the

2.1.56.

thickness are to comply with the requirements in Table

Table 2.1.56 Tolerance for Dimensions

8. Quality

(1) Each steel pipes are hydraulically or harmful defects.

non-destructively tested and are free from leakages or

(2) The steel pipes are to be of uniform quality and free from harmful defects.

9. Retest procedures

Where the tensile test, flattening test or bend test fails to meet the requirements, additional tests may be conducted according to the requirements given in 109.

10. Marking

(1) The name or brand of the manufacturer, grade of steel tubes, size and symbol of the method of the manufacture relating to (2) below are to be legibly stamped or stenciled before shipment on each length steel tube in case of 60 mm and above in outside diameter and on each bundle or container of steel tubes in case of less than 60 mm in outside diameter. The Society's brand indicating compliance with the requirements is to be in the vicinity of the foregoing marks.

(2) The symbols indicating the method of manufacture are to comply with the requirement in 401.

10 (2).

403. Stainless steel pipes

1. Application

(1) The requirements are to apply to the stainless steel pipes for low temperature service or corro- sion-resistance service (hereinafter referred to as "stainless steel pipes").

(2) Stainless steel pipes having characteristics differing from those specified in 403. are to comply

with the requirements in 101. 2.

2. Kinds

The stainless steel pipes are classified as specified in Table 2.1.57.

Table 2.1.57 Grades and Chemical Composition

3. Heat treatment

The stainless steel pipes are generally to receive a solid solution treatment. For RSTS 321TP and RbeSToSf 835407~T9P3,0 sta.bilizing treatment may be required. In this case, heat treatment temperature is to

4. Chemical composition

The chemical composition of stainless steel pipes is to comply with the requirements given in

Table 2.1.57.

5. Mechanical properties

(1) The mechanical properties of stainless steel pipes are to comply with the following requirements.

(a) Tensile test

The tensile test of stainless steel pipes is to comply with the requirements given in

2.1.58.

(b) Flattening test

Flattening tests are to be carried out in accordance with the requirements in 402.

However, where the requirements are applied, the value of e is to be taken as 0.09.

Table 5 (2).

Table 2.1.58 Tensile Test

(c) Hydraulic test

(i) Stainless steel

2.1.59.

pipes are to be hydraulically tested with the pressure specified in Table

Table 2.1.59 Hydraulic Test Pressure

(ii) In case where the test pressure higher than prescribed in (a) is specified by the pur- chaser, the test is to be carried out with the specified pressure. In this case, the test pressure need not exceed the pressure calculated by the following formula:

Mpa

where:

= Hydraulic test pressure (MPa).

= Thickness of stainless steel pipe (mm).

= Outside diameter of stainless steel pipe (mm).

= 60 % of the prescribed minimum yield strength (N m m ).

(iii) When each pipe is hydraulically tested as a regular during the process of manufacturing at the mill which makes a number of tubes continually, and the results are forwarded to the Surveyor, the test in the presence of the Surveyor may be dispensed with.

(iv) A non-destructive inspection deemed appropriate by the Society may be substituted for the hydraulic test specified in (i).

(2) The Society may require the impact test or corrosion resistance test according to purposes of stainless steel pipes.

6. Selection of test specimens

One sampling pipe is to be selected from each lot of 50 pipes or fraction thereof which are of the same charge, size and kind and are simultaneously heat treated, and each one specimen for tensile test and flattening test is to be taken from each sample pipe.

7. Tolerance for dimensions

Tolerances for the outside diameter and the

2.1.60.

thickness are to comply with the requirements in Table

Table 2.1.60 Tolerance for Dimensions

8. Quality

(1) Each steel pipes are hydraulically or ful defects.

non-destructively tested and are free from leakages or harm-

(2) The stainless steel pipes are to be of uniform quality and free from harmful defects.

9. Retest procedures

Where the tensile test or flattening test fails to meet the requirements, additional tests may be con- ducted according to the requirements given in 109.

10. Marking

Stainless steel pipes which have satisfactorily complied with the required tests are to be marked with identification mark in accordance with the requirements in 402. 10. However, the symbols in- dicating the manufacturing method of automatic arc welded steel pipes are to be as specified in the following:

Automatic arc welded steel pipe : -A

Automatic arc welded and cold finished steel pipe : -A-C

Automatic arc welded and machined steel pipe : -A -B

404. Steel pipes for low temperature service

1. Application

(1) These requirements are to apply to the seamless steel pipes and electric resistance welded steel pipes not exceeding 25 mm in thickness, intended to be used at the design temperature lower than 0 in liquefied gas carriers (hereinafter referred to as "steel pipes").

(2) Any requirement regarding the steel pipes over 25 mm in thickness is left to the discretion of the Society. See Guidance

(3) Steel pipes having characteristics differing from those specified requirements in 101. 2.

2. Kinds

The steel pipes are classified as given in Table 2.1.61.

3. Deoxidation practice and chemical composition

The deoxidation practice and chemical composition of each grade ments given in Table 2.1.61.

in 404. are to comply with the

are to comply with the require-

Table 2.1.61 Grades and Chemical Composition ( )

4. Heat treatment

The heat treatment of steel pipes is to comply with the requirements given in Table 2.1.62.

5. Mechanical properties

(1) The mechanical properties of steel pipes are to comply with the following (a) to (d).

(a) Tensile test

The tensile test of steel pipes is to comply with the requirements given in Table 2.1.62.

(b)

(c)

Impact test

The impact test of steel pipes is to comply with the requirements given in Table 2.1.62.

Flattening test

Flattening test is to be carried out in accordance with the requirements given in 402. 5 (2). Where this requirement is applied, the value of e is to be taken as 0.08. For steel pipes of 50 mm and under in outside diameter, the specimen for flattening test may be substituted for that for bend test. In this case, a test specimen of tubular section which is taken from the end of the steel pipe and has sufficient length is to stand being bent cold, up to the

specified value in Electric resistance

Table 2.1.62, without flaw and cracking on the outside of bent portion. welded steel pipes are to be bent at the place where the welded line is

(d)

on the outside of bent portion.

Hydraulic test

All steel pipes are to be subjected to hydraulic test in accordance with the requirements given in 402. 5 (4).

(2) Where deemed necessary by the Society, other tests may be required in addition to the tests specified in (1)

6. Selection of test specimens

(1) One sampling pipe is to be selected from each lot of 50 pipes or fraction thereof which are of

the same charge, size and kind and are simultaneously heat treated. tensile test and flattening test is to be taken from each sample pipe.

Each one specimen for

(2) One set of three specimens for impact test is to be taken from each sample pipe in accordance

with Fig 2.1.11. Moreover, for electric resistance welded specimens is to be taken from the welded zone in accordance

steel pipes, another set of three with Fig 2.1.12.

Table 2.1.62 Heat Treatment and Mechanical Properties

7. Tolerance for dimensions

The tolerances for outside diameter and wall thickness the requirements given in Table 2.1.63.

of steel pipes are to be in accordance with

Table 2.1.63 Tolerance for Outside Diameter and Wall Thickness

8. Quality

The steel pipes are to be of uniform quality and free from harmful defects.

9. Retest procedures

(1) Where other mechanical tests than impact tests fail to meet the requirements, additional tests may be carried out according to the requirements given in 109.

(2) Regarding the impact tests, additional tests are to be carried out according to the requirements given in 301. 10 (3).

10. Marking

Marking for steel pipes is generally to comply with the requirements given in 402. 10. and in case the requirement in Note (5) of Table 2.1.62 has been applied, "impact test temperature T" is to be suffixed to the marking. (e.g. R LP A -25T )

405. Header

1. Application

(1) These requirements are to apply to the headers to be used for boilers.

(2) The headers having characteristics differing from those specified in 405. are to comply with the

requirements in 101. 2.

2. Kinds

The headers are classified as specified in Table 2.1.64.

Table 2.1.64 Grades of Headers

3. Heat treatment

Headers are to be heat treated by annealing or normalizing.

4. Chemical composition

The chemical composition of headers is to comply with the requirements given in Table 2.1.65.

Table 2.1.65 Chemical Composition

5. Mechanical properties

(1) Tensile test: The tensile test of

2.1.66.

headers is to comply with the requirements given in Table

Table 2.1.66 Mechanical Properties

(2) Bend test: The test specimen is to stand being bent cold through 180without flaw and crack- ing on the outside of bent portion to an inside radius of 20 mm. Where the test specimen of 20 mm in thickness can not be taken, the test specimen may be as original in thickness, in which case, however, the width of test specimen is not to be less than 1.5 times the thickness and the inside radius of bend is to be equal to the thickness.

6. Selection of test specimens

(1) Tensile test specimens are to be taken lengthwise or crosswise to the rolled direction and bend test specimens to be taken crosswise to the rolled direction each from the open ends of headers.

(2) For the headers of the same size made from the same melt and subjected to the heat treatment simultaneously in the same furnace, tensile and bend test specimens are to be selected in ac-

Table 2.1.67 Number of Test Specimens

(3) Where the both ends of header are closed by reforging, the test samples of proper size may be cut from the open ends before reforging.

(4) Where test samples cut from circular headers, etc. are necessary to be flattened, the test samples are to be taken from the body before being subjected to the heat treatment and after flattening

the test samples are to be heat treated simultaneously with the body in the same furnace, or the test samples are to be cut from the structures after being subjected to the heat treatment and

after flattened cold, they are to be heated to the temperature of 600 to 650 for the pur- pose of removing the distortion due to the flattening, and the required test specimens are to be cut from the test samples.

7. Tolerance for thickness

The tolerance for thickness is to be 12.5 %. The tolerance, however, may not apply to the closed

portions of circular or square headers, the side corners of square

headers.

8. Quality

Headers are to be of uniform quality and free from harmful defects.

9. Marking

headers and the corrugated

Headers which have satisfactorily complied with the required tests are to be marked with the iden- tification mark in accordance with the requirements in 401. 10.