Frequently Asked Questions

We do not recommend using a gate valve for flow rate regulation.When a gate valve is used for flow rate regulation (intermediate opening), the disc may continue to hit against the seat, resulting in seat wear and seat leakage.

We recommend a globe valve for flow rate regulation.

Do not use a ball valve with a half-open state. The seat will be damaged, causing leakage.
(However, ball valves for flow rate regulation are excluded.)

We have no product that can be fully closed with a three-way ball valve.
Please check the switching form in our product catalog, etc.
(Ball Valve General Catalog)

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Air can also be used, but please use the valve within the maximum allowable pressure of each product.

Gate valves with non-rising structure (inner screw type) and quarter-turn valves (ball valves, butterfly valves) are applicable.

It is not recommended to use an EKE type drive part with electric stroke on one side and spring return on the other side, because the service life of the drive part will be significantly shortened due to the reduction in the repulsive force of the spring.
Please use it as an emergency shutoff valve or emergency relief valve.

For gate valves and ball valves, when the fluid is liquid, a valve may be damaged due to increase of the internal pressure when the fluid is enclosed in the cavity part inside the valve casing when the valve is fully closed, and when it receives heat from the outside, or due to volume expansion that occurs when the fluid freezes. When such usage is known in advance, it is usually handled by providing a vent hole. However, note that the flow direction of fluid is restricted. Since globe valves have a structure without a cavity part, no vent hole is required.

Basically, it is possible to change the direction of the operating device, but some products limit the direction that can be changed. Therefore, please contact your nearest sales office.

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Normally, use the bypass valve of a wafer type check valve “fully closed”.
The bypass valve is opened in the following cases.
1. When draining water from the piping for maintenance, etc.
2. When priming water is required when starting the pump (bleeding the air in the piping)

Except for the electric automatic valves: ES series (Petit KELMO), the valve can be used outdoors. However, it cannot be used in an environment where it is exposed to direct sunlight or direct water spray, so please protect it with a roof, etc. For details (protection rating, etc.), refer to the catalog and each instruction manual.

Except for the pneumatic automatic valves: C series, the valve can be used outdoors. However, it cannot be used in an environment where it is exposed to direct sunlight or direct water spray, so please protect it with a roof, etc. In addition, depending on the installation posture, water may enter from the breathing port and cause problems. For details (protection rating etc.), refer to the catalog and each instruction manual.

It is possible to use the BC valves and cast iron valves with light oil, kerosene, and heavy oil in terms of corrosion resistance. However, please note that these fluids fall under the category of hazardous materials in areas where the Fire Service Act is applicable, such as around oil tanks, and there are restriction on materials. Valves that can be used for hazardous materials are valves made of ductile cast iron, cast steel, and stainless steel. We recommend installing valves made of ductile cast iron or better even when installing in areas where the Fire Service Act is not applicable.

Please select from the valves for water supply provided by us or the products that passed inspection by the Japan Water Works Association, the products certified by the Certification Center or the products that conform to the lead leaching performance standards.

We do not recommend posture change by our customers after purchase.
If you need to change the installation direction, please contact your nearest sales office.

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The temperature varies depending on the product and use method, but rough guides for general products are as follows.
When the temperature is below these values, it may be handled with special specifications. Please identify the use conditions, such as fluid, temperature, and pressure, and contact your dealer.
When using at minus temperature, “no freezing of fluid” is an absolute condition.

Do not use bronze / brass valves for flammable gas or toxic gas. (The catalog clearly states that flammable gas and toxic gas are excluded.)
However, this does not apply to gas valves.

Please refer to the catalog for gas valves.
(General Catalog, Digest Version_13-Gas)

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A globe valve can be used with a “half-open” state.
However, do not use it in a “half-open” or “slightly open” state that causes vibration due to the fluid.
Vibration may break the valve shaft or damage the disc or valve seat surface.

A rough guide for the average flow velocity in the pipe required to keep the disc at a constant opening is as follows for a swing type check valve.
“For water”: 1 – 3 m/s
“For gas”: About 30 – 50 m/s when the pressure is about 100 KPaG with normal temperature air
A check valve may cause chattering even if the flow velocity is too slow or too fast, shortening the service life of the valve.
We recommend to select the valve size so that an appropriate flow velocity can be obtained.

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