1. Scope

This Japanese Industrial Standard specifies the carbon steel tubes, hereinafter refered to as the "tubes", used for excahnging heat on the inside and outside of the tube, such as water tubes, smoke tubes, superheater tubes, air preheater tubes, etc. of the boiler, and heat exchanger tubes, condenser tubes, catalyser tubes, etc. used in chemical and petroleum inudstries.

however, it is not applicable to the steel tubes for heating furnace and steel heat exchager tubes for low temperature service.

Remarks

1. The purchaser may desingate in addition to the items spectfied in this text, by prior agreement with the manufacturer, part or all of the items in the supplementary quallity requirements Z1, Z2, Z3 and Z4 specified in Appendix 1 and the item of the U-bend tube specified in Appendix 2. 

2. The units and numerical values given in { } in thsi Standard are based on the International System of Units (SI) and are appended for informative reference.

Further, the traditional untis accompanied by numerical values in this Standard shall be converted to the SI units and numerical values on Jan. 1, 1991.

2. Classes and Symbols
The tube shall be classified into 3 grades and their class symbols shall be
as given in Table 1

                                                              Table 1 Class Symbols (Applicable till the end of 1990)

Class new	(Informative reference) Traditional sysmbol
STB 340 STB 410 STB 510	STB 35 STB 42 STB 52

World standard comparative table

3. Method of manufacture

4.Chemical Compostion

The tube shall be tested in accordance with 9.1 and the resulting ladle
analysis values shall conform toTable 2

Table 2. Chemical Composition
(Applicable till the end of 1990)

Remarks

1. When the purchaserrequires product analysis, the permissible
deviation for thevalues given above shall be as specified in
Table in JIS G 032 for the seamless seel tube and likewise
in Table 1 for the electric resistance welded steel tube.

2.Where equired by the purchaser, Si may be designated as 0.10 to 0.35%

5. Mechanical Properties

6. Hydrostatic Characteristic or Nondertructive Charateristic

7. Apperance 
(1) The tue shall be practically straight and its both ends shall be at
right angles to its axis.

(2) The inside and outside surfaces of the tube shall be well-finished and
free from defects injurious to ues. However, in the cas of electric resistance welded tube the swelling of inside surface of the weld shall be 0.25mm or less. In thes case, if necessary, the purchaser may specify the inside swelling as 0.5mm or less for the tubes 50.8mm or under in outside diameter and at the same time 3.5mm or under in wall thickness.

8.Dimensions, Mass and Dimensional Tlerances
   

9. Test

10. Inspectiont

11. Reinspection The tube may apply for a retest specified in 4.4 of JIS G 0303 for final acceptance.

12. Marking
Each tube haing passed the inspection shall be marked with the following itmes. However, the order of arranging the items is not specified. Further, in the case of either smaller tubs or request from the purchaser, the tubes may be bundled together and marked for each bundle by a suitable means.

(1) Class symbol

(2) Letter sumbol indication the manufacturing method()

(3) Dimensions

(4) Manufacturer's name or its abbreviation

(5) Letter sumbol Z indicationg the designation of special quality requirements

    Note () Symbols for indicaiong the manufacturing method shall be as follows. However, - may be replaced by a blank.

Hot finished seamless steel tube -S -H
Cold finished seamless steel tube -S -C
Electric resistance welded steel tube other than Hot finished and cold finished -E -G
Hot finished electric resistance welded steel tube -E -H
Cold finished electric resistance welded steel tube -E -C

13. Report
The manufacturer shall, in general, submit to the purchaser a detailed statement of the test results, method of manufacure, ordered dimensions, quantity, work number indicationg the history of manufacture, etc.