SGP

1. Used to transport water (not drinking water), air, steam, oil, and gas, as well as other fluids at relatively low pressures. Plastic-lined steel pipe manufactured by coating JIS G3452 SGP is used for water delivery pipelines (carbon steel pipe for ordinary piping)
2. There are two distinct types: black pipe and white pipe. Temperature range of operation: -15 to 350°C.
3. MZN grade groove corrosion-resistant ERW steel pipe is also available to defend against groove corrosion along ERW steel pipe welds.

• The manufacturing process of JIS G3452 SGP pipes begins with either electric resistance welding or butt welding. Once the pipes have been created, they are delivered as is. However, the cold-finished pipes go through an additional step of being annealed after manufacturing. This annealing helps to improve the strength and ductility of the pipes, making them less susceptible to fracture. 
• Both ends of pipes of nominal diameter 300A or under must be threaded or plain-ended. This is to ensure that the pipes can be securely connected to other pipes or fixtures. Similarly, for pipes of nominal diameter 350A or over, only plain-ended connections are allowed. This is to prevent leaks and other potential problems that could occur with threaded connections. Finally, when specified by the buyer, pipes may be furnished with bevel ends. This allows for a more secure connection and also provides a nicer appearance.
• For threaded pipes, taper threads specified in JIS B 0203 shall be applied on both ends. A socket as in JIS B 2301 or JIS B 2302 shall be screwed into one end of the threads. The other end with a socket not screwed shall be provided with a thread protecting ring or protected by other suitable means. When specified by the purchaser, the threaded pipe may dispense with a socket. The taper threads shall be inspected in accordance with JIS B 0253.

• Before threading white pipes, the pipes and sockets shall be zinc-coated. In this case, black pipes and sockets that passed the inspection shall be thoroughly cleaned by sand blasting, pickling, etc., then zinc-coated by hot dip galvanized coating. Zinc used for zinc-coating shall be the distilled zinc ingot Class 1 specified in JIS H 2107 or zinc ingot at least equivalent thereto. Other general matters of zinc-coating shall be in accordance with JIS H 8641. This is to ensure that all pipes are protected against corrosion and wear.

JIS G3452 chapter 10.6 shall be used to test the SGP black pipe, and the resultant hydrostatic or nondestructive characteristic shall conform to one of the following two. Whichever of them is preferred shall be determined by the purchaser’s specification or at the manufacturer’s discretion.

Hydrostatic property (Applicable till the end of 1990) When 25 kgf/P 25 bar (1) hydrostatic pressure is applied, the black pipe must endure it without leaking.
 Note (1) 1 bar = 105Pa