JIS G3452

JIS G3452 pipes should be categorized into one grade, with its letter symbol being as shown in the following table, and further separated into black pipes and galvanized pipes based on the presence or absence of zinc-coated coatings on the outside of the pipe.

Note：

  • When the Tensile test is performed on the No. 12 or No. 5 test piece for a pipe with a wall thickness of less than 8mm, the minimum value of elongation shall be obtained by subtracting 1.5 percent from the values of elongation given in Table 3-1 for each 1mm decrease in wall thickness and rounding off to an integer by JIS Z 8401, the minimum value of elongation shall be obtained by subtracting 1.5 percent from the values of elongation In the Reference Table, you can find examples of calculations.
  • The elongation values shown in the table are not applicable to pipes with a nominal size of 32 A or less, as specified in the table. The value of elongation, on the other hand, must be documented.
  •  If the tensile test pieces are being sampled, the No. 12 and No. 5 test pieces should be obtained from the area of the component that does not have any welded seams.

• According to JIS G3452, pipes shall be manufactured by electric resistance welding or butt welding. Pipes shall be delivered as manufactured. However, the cold-finished pipes shall be annealed after manufacturing. This is done to relieve stress that has built up during the manufacturing process and to improve the pipe’s ductility and toughness.
• The standard for both ends of pipes is that they shall be either threaded or plain-ended. Pipes of a nominal diameter 350A or over shall have plain ends, while those of 300A or under may have either type of end. When the buyer specifies, pipes may be ordered with beveled ends instead. The shape of the bevel is to be agreed upon between the buyer and manufacturer, but absent such an agreement, it shall conform to the illustration below.
• JIS B 0203 describes the standards for taper threads on threaded pipes. The taper threads specified in JIS B 0203 shall be applied on both ends of the pipe, and a socket as described in JIS B 2301 or JIS B 2302 shall be screwed into one end of the threads. The other end of the pipe, which will not have a socket screwed into it, shall be provided with a thread-protecting ring or protected by other suitable means. If the purchaser specifies, the threaded pipe may dispense with a socket. The taper threads shall be inspected by JIS B 0253 before use.

• Before pipes and sockets are threaded, they zinc-coated. If the inspection passes, the pipes and sockets shall be cleaned by sandblasting, pickling, etc., then hot dip galvanized. The zinc used shall be distilled zinc ingot Class 1 specified in JIS H 2107 or at least equivalent thereto. Other general matters of zinc-coating shall be by JIS H 8641. Zinc coating protects the metal from corrosion and makes it last longer. It is essential in places where pipes and sockets are exposed to moisture or chemicals.

Analytical Chemistry In line with JIS G 0303, general topics common to chemical analysis, as well as the process of sampling specimens for chemical analysis, should be followed.

A technique of analysis in compliance with one of the following Standards must be used: Analytical Method

The JIS G 1214, JIS G 1215, JIS G 1253, JIS G 1256, and JIS G 1257 standards are among the most widely used in the world.

- Tensile Test

- Hydrostatic Test or Nondestructive Test

- Flattening Test

A label containing the following information should be placed on each pipe that has passed inspection: smaller pipes and other pipes were chosen by the purchaser, on the other hand, maybe bundled together and tagged with a unique identification number for each bundle. The sequence in which the indicated items should be arranged is not stated in either situation.

Part of the products may be omitted if the purchaser gives his or her approval.

  • The grade is represented by a letter sign.
  • A letter sign that represents the manufacturing processes
  • Dimensions
  • Manufacturer’s name or its identifying brand