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HOME > 経営をよくする > Vibrant SMEs of JAPAN

Vibrant SMEs of JAPAN


Freeing Operators from the Hardships of Underwater Maintenance by Eliminating the Need for Underwater Work [ Ishizaki]

Secret to Robustness
  • Developed a valve that frees operators from the hardships of underwater maintenance.
  • Growing sales with an entirely new product not found anywhere else in the world.
  • Venturing into new elemental technology to enable in-house production of parts.

Established in 1935, Ishizaki manufactures and sells check valves for pumped-storage systems that pump up and use water from water tanks. The check valves are used to prevent the reverse flow of liquid. On the other hand, the company also has the face of a "trading firm" that handles sanitary ware and pipes used in household equipment as well as tiles for use as residential building materials. Therefore, in October 2013, the company changed its name from Ishizaki Manufacturing. The company is now experiencing a new surge of growth, and the product driving that growth is the "foot valve". In the three years since it was first released, sales have grown at rate that is more than double the annual rate.

Searched for True Needs through a Market Survey

The foot valve is a valve that is attached to the entrance of a suction tube of a pump in a pumped-storage system. Conventionally, the valve is attached to the end of a tube and sunk down into a water tank. However, when an inspection or replacement is needed, the valve has to be either pulled up out of the water, or if that is too difficult, water has to be drained from the water tank, and if the water cannot be drained, a diver has to dive into the water to inspect or replace the valve. In addition to maintenance being difficult underwater, another problem is that these types of underwater valves rust and deteriorate. To solve these problems, Ishizaki developed a foot valve that is attached above ground.
What led to the development was information from a market survey that was conducted for the purpose of improving check valves. "A lot of customers were really struggling with maintenance of the foot valve on the suction side. Wanting to do something about this, we embarked on efforts to develop a foot valve that could be installed above ground," reflected Executive Officer Kazunori Chiba.
The foot valve that was developed as a result is installed midway in a pipe above ground rather than at the end of the suction tube, and because it is above ground, it doesn't rust, and it can be easily inspected. A weak spring was adopted to make suctioning easy, and soft packing was adopted so that water can be stopped even with a weak force. According to Executive Officer Chiba, "This product didn't exist anywhere in the world, and for customers using foot valves in water, it's easy to imagine how much simpler it will be to use this valve."
Examples of pumped-storage systems that use foot valves include coolant circulation lines in factories, water supply lines of water purification plants, and water circulating lines for air conditioning equipment in buildings. Ishizaki initially narrowed its target to foot valves for use in coolant circulation lines in factories and visited the plants of major manufacturers with annual sales of over 100 million yen to introduce them to the foot valve that can be connected above ground. According to Executive Office Chiba, "The immediate response was, ‘if there's a product like that, we definitely want to try it.'"
The foot valve product that was commercialized initially was made of cast iron, but in June 2013, the company began selling a foot valve made of stainless steel. The valve made of cast iron exhibited high resistance when water was suctioned, so water could only be suctioned from shallow areas, and the areas in which the foot valve could be used were limited. However, by making the foot valve of stainless steel, the resistance decreased, making it possible to use the valve in every zone of a water tank. In addition, the energy used to operate the pump can also be conserved, so another merit is the ability to save more money on electric bills compared to conventional foot valves. Also, the weight is less than half that of the valve made of cast iron, so the work burden when handling the valve is significantly reduced.

Goal to Replace All Valves in 10 Years

For the full-scale mass production of the stainless steel foot valve, Ishizaki recruited people experienced with welding and resin cutting, and introduced dedicated equipment at its Ibaraki Plant. This was done because until that point, the company had only been involved in manufacturing valves made of cast iron, so it didn't have the technology to process stainless steel and resin. Initially, production of the stainless steel foot valves was outsourced, but after extensive training in-house, the company expects to be able to manufacture all of the parts in-house beginning in the spring of 2014. According to Executive Office Chiba, "Manufacturing the product in-house will give us ideas on how to further improve the valve."
Along with the change in the company name, Ishizaki also adopted the management slogan "Giving form to ideas." The product that truly embodies these words is the foot valve. Domestically, there is a demand for 3 million pumps per year, and the market for foot valves is contained within this number. "We intend to replace all of the in-water foot valves of pumped-storage systems operated in Japan with our foot valve that can be attached above ground within 10 years." (Executive Office Chiba) To achieve this, the company is zealous about its daily business operations and is preparing the necessary production system.

Stainless steel foot valve that is attached above ground

Stainless steel foot valve that is attached above ground


One Point: Key Point is Foreign Market

Sights Set on Overseas Expansion

Until now, check valves have been the main pillar of Ishizaki's valve business. However, moving forward, the company intends to foster foot valves as a new business pillar and to thereby create a two-pillar business for sales. The foot valve that can be attached above ground is an entirely new product that cannot be found anywhere else in the world, so the company has plenty of allowance to expand sales significantly by replacing underwater foot valves. The concern, however, is that similar products will emerge. To prevent this, the company has acquired basic patent rights for the foot valve that can be attached above ground and has filed patent applications for overseas patents. With a certain level of success being achieved in Japan, next the company wants to set its sights on overseas expansion.

Company Data

Tomoyuki Ishizaki

President :
Tomoyuki Ishizaki

Company name ISHIZAKI Co.,Ltd.
President Tomoyuki Ishizaki
Industry Type Manufactures and sells check valves and foot valves.
Address 5-29-14 Kugahara, Oota-Ku, Tokyo-To, Japan
Phone 046-245-3871

Printing day:April 4, 2014

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