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| All operation sites | 1986 | Gained full membership of Japan Water Steel Pipe Association (WSP) |
|---|---|---|
| 2007 | Obtained ISO14001 certification | |
| All operation sites (excluding the administration division and some sales divisions) |
2009 | Obtained ISO9001 certification |
| Narita Shibayama Plant | 1998 | Obtained ISO9002 certification |
| 2004 | Obtained ISO9001 certification | |
| 2011 | Registered by Japan Water Works Association (JWWA) as a certified inspection plant for steel pipe with its outer surface coated with rigid PVC | |
| Hashimoto Plant | 2008 | Registered by JWWA as a plant certified for quality of flexible pipe HF |
| 2009 | Obtain ISO9001 certification | |
| Harima Plant | 1998 | Registered by JWWA as a plant certified to conduct in-house quality confirmation of flexible pipe HF |
| 2007 | Obtained ISO9001 certification | |
| 2007 | Registered as a Green Partner under the Green Partner Initiative of Osaka Gas Co., Ltd. | |
| Nagano Plant | 1992 | Became a certified welding facility |
| 2007 | Obtained ISO9001 certification | |
| 2007 | Registered as a Green Partner under the Green Partner Initiative of Osaka Gas Co., Ltd. |