Frequently Asked Questions (FAQ)

The FAQ page shows the frequently asked questions about the use of magnetic fluid seals and the answers.
Also, it provides answers to the questions about the Company.
If you have any questions not covered in this page or any general inquiries, please contact us from the general Contact Form.

• Questions about adoption of magnetic fluid seals
• Questions about trouble with magnetic fluid seals
• Questions about maintenance and overhaul of magnetic fluid seals
• Questions about the Company

Questions about adoption of magnetic fluid seals

Currently, we use O-rings, oil seals, mechanical seals and Wilson seals for the shafts to feed rotational motions into the vacuum chambers. Is it possible to replace these seals with magnetic fluid seals? What are the advantages and disadvantages of using magnetic fluid seals?

Yes, it is possible to replace them with magnetic fluid seals.
Advantages
Magnetic fluid seals provide higher cleanliness and longer service life.
Because of the liquid contact with magnetic fluid, clean environment is maintained, without generation of heat and dust due to solid friction.
Please see the “What is a magnetic fluid seal?” page for details of advantages of magnetic seals. Disadvantages
Initial cost should be considered. However, you can have longer maintenance cycle and reduced total cost.
Please contact our sales personnel for details.

What is the upper limit of rotation rate for your magnetic fluid seal?

We have achieved peripheral speed of 21m/s (with shaft diameter φ40, 10000rpm) (special specification). Please contact us from the Inquiry Form for details.

What is the upper limit of operating temperature of your magnetic fluid seal?

We have achieved the operating temperature atmosphere inside the vacuum device exceeding 1000 ℃(special specification).
Please contact our sales personnel for details.

Can your magnetic seals be used for a liquid or powder stirrer?

Our magnetic fluid seals have been used for industrial adhesive stirrers and for sludge treatment equipment.
Please note that magnetic fluid seals cannot seal liquids directly.
Also note that any condensation of liquid used (such as solvents and media) on the sealing section can cause sealing failure or leakage.
If you need detailed information, please tell us your operating conditions from the Inquiry Form.

Can your magnetic fluid seals be used for vacuum chucks?

Yes.
Our magnetic fluid seals ensure high-speed rotation and firm adsorption of samples without damaging samples.
Please see the Applications / Results – Vacuum chuck for details.

Can your magnetic fluid seals be used for gas introduction?

Yes.
Gases of multiple systems such as reactant gas and purge gas can be introduced from the magnetic fluid seals.
The equipment as a whole will be simpler and more compact.
Please see the Applications / Results – Gas introduction mechanism for details.

Can your magnetic fluid seals be used in a corrosive gas atmosphere?

We propose the magnetic fluid seal suitable for the type, temperature and concentration of gas.
Please contact us from the Inquiry Form for details.

We need a quick delivery. Can you shorten the delivery time?

We cooperate your needs to shorten work schedule.
As we can also propose short delivery products, please contact our sales personnel.

Can you manufacture special order products?

We respond to a special order from one unit. According to your request, we offer designs utilizing our experiences.
Please contact our sales personnel.

Is there a recommended frequency for replacing magnetic fluid seals?

The frequency of replacing varies according to your operating conditions.
Please contact our sales personnel for details.

Can your magnetic fluid seals be repaired? How much does it cost and how long does it take to repair?

Of course, they can be repaired.
To apply for repairment, please send the item to us without disassembling, or please contact our sales personnel.
How much does it cost to repair?
As a rough standard, it is about half the price of a new product. (It varies according to the repair contents.)
How long does it take to repair?
After you send back the magnetic fluid seal, we will make a written estimate for repair.
The rough standard delivery period for repairment is about three weeks from the repair request.

Does a magnetic fluid seal have a warranty period?

The warranty period is one year from shipping.

Is there an instruction manual for magnetic fluid seals?

You can download the Instruction Manual from here.

Are O-rings, keys and water cooling joints supplied with your magnetic fluid seals?

A set of O-rings used for grooves are supplied with the product.
If you need spare items, please tell us upon placing of your order.
Keys and water cooling joints are not included. Please prepare by yourself according to your applications.

What is the flow rate of cooling water and the pressure resistance of the magnetic fluid seals of water cooling type?

The rough standard of flow rate is 1L/min. This amount is sufficient. They can withstand the pressure up to 0.5MPa.

Are your magnetic fluid seals compliant with the RoHS?

All our standard products comply with the RoHS.
For special specification products, we issue a certificate individually.

What is the magnetic circuit unique to Rigaku?

Rigaku’s magnetic fluid seals adopt a unique magnetic circuit configuration using multiple magnets.
This unique magnetic circuit allows our products to have higher sealing performance, higher resistance to external magnetic field, and fewer leakage magnetic fields than those made by other companies.
Please see the What is a magnetic fluid seal? page for details.

What is a clean magnetic fluid that can be used at high temperature and in high vacuum?

Rigaku’s magnetic fluid for high-temperature / high-vacuum applications is a clean magnetic fluid which achieves the industry’s lowest level of outgas.
It is ideal for semiconductor manufacturing and other process environments where contamination is strictly prohibited.
Please see the What is a magnetic fluid seal? page for details.

Can a part of standard product shape be modified?

Of course, yes.
Please feel free to ask us for modification of a mounting hole, changing of shaft length, flange cut, etc.
Please note that a change in the shape requires a delivery period longer than the standard product.
Please contact our sales personnel for details.

Questions about trouble with magnetic fluid seals

The pressure inside the equipment will not go down. Is the magnetic fluid seal a possible cause?

There are following three possible causes for this trouble:
(1) Leakage from the magnetic fluid seal
(2) Leakage from the section for mounting the magnetic fluid seal
(3) Leakage from other parts

If it seems to be the case (1), please contact our sales personnel.

The pressure inside the equipment does not stabilize. Is the magnetic fluid seal a possible cause?

In order to determine whether the cause is the magnetic fluid seal or other parts in the equipment, please check the variations in pressure according to the rotation of magnetic fluid seal first, and contact our sales personnel.
(When you start the equipment after a prolonged period of disuse, a temporary pressure variation may occur upon the start of rotation.)

The rotation of magnetic fluid seal has become slow.

There are following six possible causes for this trouble:

(1) Leaving it in disuse for a prolonged period of time
(2) It is winter or a low temperature
(3) Deposition of products on the surface and / or the inside of magnetic fluid seal
(4) Entry of foreign matters to the inside of magnetic fluid seal
(5) Deterioration of bearing grease
(6) Damaged bearing

In the case of (1) or (2), the problem may be eliminated by pre-conditioning operation.
Please see the section of “What is a pre-conditioning operation?” in the FAQ for details of pre-conditioning operation.
If the problem is not eliminated after the pre-conditioning operation, please contact our sales personnel.

The magnetic fluid seal stopped rotating.

Overhaul is required. Please send it to us without disassembling, or contact our sales personnel.

The magnetic fluid seal has come into contact with water / organic solvent.

Please contact and inform our sales personnel about the type and the approximate quantity of liquid in contact.
Depending on the information, sending back for investigation and repair may be necessary.
In this case, the cost of investigation and repair will be charged to you even within the warranty period.

I dropped the magnetic fluid seal.

Please contact our sales personnel and inform about the height of dropping, the conditions of crashed parts, etc.
Depending on the information, sending back for investigation and repair may be necessary.
In this case, the cost of investigation and repair will be charged to you even within the warranty period.

Liquid has spilt from the magnetic fluid seal.

Immediately stop the equipment and contact and inform our sales personnel about the conditions.

The magnetic fluid seal makes abnormal sounds.

Immediately stop the equipment and contact and inform our sales personnel about the conditions.

Questions about maintenance and overhaul of magnetic fluid seals

Can magnetic fluid seals be repaired? How much and how long does it take to repair?

Of course, they can be repaired.
To apply for repairment, please send it to us without disassembling, or please contact our sales personnel.
How much does it cost to repair?
As a rough standard, it is about half the price of a new product. (It varies according to the repair contents.)
How long does it take to repair?
After you send back the magnetic fluid seal, we will make a written estimate for repair. The rough standard delivery period for repairment is about three weeks from the repair request.

Can magnetic fluid seals be repaired by ourselves?

No. Do not repair magnetic fluid seals by yourself.
To apply for repairment, please send it to us without disassembling, or please contact our sales personnel.
Please note that any magnetic fluid seals disassembled by yourself will not be covered by warranty.

Is there a recommended frequency for replacing magnetic fluid seals?

The frequency of replacing varies according to your operating conditions. Please contact our sales personnel for details.

What is “a pre-conditioning operation” of magnetic fluid seal?

It is a warming-up operation of magnetic fluid seal to reduce pressure variations during starting of the magnetic fluid seal rotation.
Please rotate the shaft 20 times or over before the start of vacuuming. You can use any type of driving.

How should we store magnetic fluid seals?

When storing magnetic fluid seals, please keep them in the packaging as they were shipped and in a place with little change in temperature.
In the case that you have opened the packaging for shipping, please cover the magnetic fluid seals with a plastic bag, a wrapping film, etc. and store in a place with low humidity, minimal dust and little change in temperature.

We kept magnetic fluid seals stored for a long time without using. Can we use them without problems?

Yes, you can. Before using, please carry out pre-conditioning operation sufficiently.
For an explanation of pre-conditioning operation, please read the section of What is “a pre-conditioning operation”?

Questions about the Company

Have you obtained any ISO certifications?

Yes. We have been certified to ISO9001 and ISO14001 (both for the 2015 version).

Where do you manufacture your products?

All of our processes from design to manufacturing are conducted in Japan.