ERDIP (Earthquake Resistant Ductile Iron Pipe)

Earthquake Resistant Ductile Iron Pipe (ERDIP)

In 1893 Kubota began supplying iron pipes for the safe delivery of drinking water in Japan. Since then Kubota has been working continuously on technical innovation and developing superior pipe products so that in 1974, Kubota released the world’s first Earthquake Resistant Ductile Iron Pipe (ERDIP).


Kubota’s ERDIP which can be used for anything from distribution lines to trunk lines, and ranges in size from 3 to 104 inches (75 to 2600 mm), has had no documented failures or leaks caused by earthquakes, including the 2011 Great East Japan earthquake which measured 9.0 on the Richter scale. This excellent seismic performance is why Kubota’s ERDIP is used by so many Japanese water agencies today.


Since its introduction the volume of ERDIP produced by Kubota has increased steadily with marked growth beginning after the 1995 Kobe earthquake. ERDIP has become so popular that it now accounts for over 90% of the ductile iron pipe market in Japan, with over 41,000 miles of ERDIP pipe being installed so far.  That’s enough to go around the world one and half times! We have also started to see ERDIP being adopted by municipalities in the U.S. and Canada including Los Angeles, San Francisco and Vancouver.

 Los Angeles County Installation

Santa Clara Valley Installation


We are confident that our unique ERDIP product will help improve the resiliency and reliability of our owners’ water supply for years to come.



The ERDIP absorbs the large ground displacement by joint extension/contraction, deflection, and

anti-pull out structure. When one joint fully extends, the joint can pull the next pipe one after another like a buried chain. Therefore, we call this pipeline a “Chain Structure Pipeline”.

Joint Performance

Kubota ERDIP has the highest performance rankings for all categories of ISO 16134:2020 Earthquake-resistant and subsidence-resistant design of ductile iron pipelines.

θa : The joint deflection angle is shown in table below

ERDIP is Effective in Natural Hazards other than Earthquakes

Besides its earthquake resistant purpose, ERDIP also performs effectively against ground displacement caused by other disasters such as landslides, subsidence, hurricanes, liquefaction etc. This is why our ERDIP is also known as Hazard Resilient Ductile Iron Pipe (HRDIP).


 Road collapse caused by heavy rain; no damage


Road collapse caused by heavy rain; no damage


Road collapse caused by tsunami; no damage


Road collapse caused by tsunami; no damage



Kubota Membrane USA Corporation, ERDIP Dept, for North America

3528 Torrance Boulevard, Suite 112 Torrance, CA 90503

Tel: +1 424-358-5200



To learn more about Kubota Ductile Iron Pipe click below

DIP (Kubota Global Website)  

ERDIP Movie