This Standard specifies the steel pipe fittings attached by butt-welding to ordinary pipings 1)carrying steam, water, oil, gas, air, etc. of comparatively low working pressure (hereafter referred to as “pipe fittings”).

Annex A specifies the pipe fittings of special shapes not given in the main body of this Standard, which may be designated upon agreement between the purchaser and the manufacturer, and Annex B shows matters related to the marking and report of the pipe fittings with special necks for informative reference.

Note 1) Pipings using carbon steel pipes for ordinary piping specified in JIS G 3452 and pipings using arc welded carbon steel pipes for piping specified in JIS G 3457.

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Click here for PDF of JIS B2311-2009 Steel butt-welding pipe fittings for ordinary use>>>

JIS-B2311-Steel-butt-welding-pipe-fittings-for-ordinary-use.pdf

Research use only,Commercial use is prohibited. 
If you want to use it ,you can buy from following link:
http://www.webstore.jsa.or.jp/webstore/Com/FlowControl.jsp?lang=en&bunsyoId=JIS+B+2311%3A2015&dantaiCd=JIS&status=1&pageNo=0