Specialist in Roots Vacuum Pump and Roots Blower in Japan


We have answers to your company’s special needs with our unique technology.

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New product VP1 series

Roots Vacuum Pump

「Reliable VP Type vacuum pumps meet the diversified needs of the industrial sector」

The VP Type vacuum pumps manufactured by YKS (Yotsuba air machine M.F.G Co., Ltd) are multi-stage roots type dry oil-free vacuum pumps that adopt a cooling technique which is unique to other similar products. YKS’ direct rotor cooling system, which has made it possible to realize completion blocked operation on the roots type high-vacuum pump, is a system of new technique developed on the basis of the company’s original technologies. The Roots-type vacuum pump runs free of contact between the rotors or between these and the casing, with a slight clearance secured in between them. For this reason, the pump is of the dry oil-free type, the most distinctive feature of the pump. However, the tiny clearance for noncontact rotation of the pump will be reduced by the thermal expansion of the rotor, etc., originating from compression heat or gas, eventually giving rise to contact, unless the compression heat is somehow eliminated. Since the direct rotor cooling system developed by YKS is structured to directly cool the interior of the rotor with coolant, it offers numerous advantageous features, including that of always maintaining a constant clearance and stable degree of vacuum. The conventional cooling systems did not allow the manufacture of vacuum pumps from stainless steel due to the large thermal expansion this type of steel produces (1.8 times that of normal steel). Nonetheless, YKS has succeeded in developing such stainless steel pumps by making the most of the excellent characteristics of the direct cooling system. These pumps are providing super performance in their applications to the aspiration of corrosive gases.

Mechanism & Features

The VP Type pumps solve your problems

  • Suction of corrosive gas
  • Suction of high-temperature gas
  • Oil pollution surrounding the pump
  • Problems carried by waste water treatment
  • Difficulty of drain at intercooler
  • Suction of powder dust
  • Suction of condensable/coagulable gas
  • Instability of the vacuum due to temperature variation
  • Large space required
  • High cost of utility
  • Oil-back contamination carried by vacuum chamber
  • Fast consumption and deterioration of sealing oil
  • Impossibility of continuous operation due to condensate
  • Equipment other than vacuum pump required
  • Lack of durability of vacuum pump
  • Troublesome maintenance

Examples of uses: The VP Type vacuum pump provides stable vacuum at all times for these applications.

Vacuum distillation Vacuum melting Vacuum concentration Chemical Vapor Deposition
Vacuum deaeration Pressure Swing Adsorption Vacuum packaging Sputtering
Vacuum drying Vacuum heat treatment Vacuum deodorization Etching
Vacuum casting Vacuum sintering Vacuum deposition Vacuum chuck
Vacuum distillation Vacuum melting
Vacuum concentration Chemical Vapor Deposition
Vacuum deaeration Pressure Swing Adsorption
Vacuum packaging Sputtering
Vacuum drying Vacuum heat treatment
Vacuum deodorization Etching
Vacuum casting Vacuum sintering
Vacuum deposition Vacuum chuck

vacuum is completely dry and clean.
No oil, water, etc, will mix in

  • The vacuum chamber and the cooling and lubricating chambers are completely isolated from each other, with independent discharge systems. This eliminates all possibility of mixing of water, oil or other pollutants.
  • Rotors run free of contact with casing. Hence, no wear will occur.

Continuous operation is available for condensed gas services in case of suction of condensable gases, a rotor discharges such ases by force.

  • Condensed liquid does not remain in a pump and a continuous operation is possible.
  • By installation of an after-cooler at a discharge side, it is possible to collect solvents efficiently.
  • As a direct cooling construction is provided and an inter cooler is not required, a condensed liquid is easily discharged

It is easy to clean inside the vacuum pump casing.

  • With the possibility of condensation or coagulation occurring inside the vacuum pump, the interior can be cleaned simply with solvent, etc, injected through the internal cleaning nozzle-ports.
  • There is another way of cleaning while the pump is in operation

High-temperature gases (approx.130℃) can be sucked in directly.

  • The direct cooling system adopted allows you to suck in high-temperature gases.

Force feeding can be done at the same time as sucking.

  • Force feeding can be conducted at a back pressure of max. 0.5kg/cm2G on the standard type, or max. 1kg/cm2G on a special type.

Continuous operation can be carried out at different degrees of vacuum from  atmospheric pressure to shut-off operation. Choices of materials for parts in contact with gas

When corrosive gases or special gases are to be sucked in, a variety of choices are available for the materials of the parts that come into contact with those gases.

Reverse rotation prevention mechanism

  • Since the VP Type pump adopts the Roots system, the rotor rotates inversely as gas flows back if the pump is stopped while  the suction side is still in vacuum. To prevent such phenomenon from breaking the pump and contaminating the vacuum unit, the pump is equipped with reverse rotation prevention mechanisms as standard.

Over-compression prevention mechanism

  • The VP type pump is provided with an over-compression prevention mechanism, so that it can be operated smoothly over the entire process from  atmospheric pressure to the ultimate vacuum (shut-off operation). The mechanism prevents overloading from occurring due to over-compression in the proximities of the atmospheric pressure.

Countermeasures and solutions for sucking condensable or coagulable gases

This type of pump prevents gas  condensation by heating the bottom of each self of the vacuum chamber. Thus, water can be recovered easily on the discharge side while the pump is operating. The steam tracing tubes for heating are available as an option.

Coagulable gases that tend to adhere to the inside of the pump can be cleaned easily with solvent or steam injected through the internal cleaning nozzle ports (equipped as standard) at the top of the pump.

Moreover, sucking of condensable or coagulable gases can be made easy when hot water (max.60℃) is used, in lieu of the cooling water.

Pressure-equalizing mechanism for completely dry pumps

When a vacuum pump is started, the oil inside the oil chamber tends to flow  at the same time as the gas flowing into the gland section when vacuuming occurs. To prevent this, our VP type pump has a side oil case equipped with a pressure-equalizing mechanism as standard as unique safety measure.

By attaching the pressure-equalizing mechanism outside the oil chamber it has led to an enhanced oil separation performance. Moreover, the burden on the oil seal due to differential pressure has been minimized, which results in enhanced sealing property and extended life.


  • Stainless steel vacuum pump for corrosive gas
  • Fluoropolymer lining vacuum pump for corrosive gas
  • VP3
  • VP4
  • VMP13
  • VMP14
  • VMP24

This is the best pump to suck corrosive gasses!

Our blower is suitable for sucking condensable gases.

It is easy to remove coagulation and polymerization from inside of the pump.

We have delivery experience in Roots-type dry vacuum pumps with Austenitic stainless steels (SCS13/14/16), considered hard to use in dry vacuum pumps due to its high thermal expansibility, we have made it possible with our unique cooling system that cools where the gas comes in contact with the Austenitic stainless steel. We can manufacture moldable corrosion-resistant alloy (Ni – Cr – Mo casting, etc). If you have problem with corrosion, please think about this. Please contact us for details.

Model VP4- 501 VP4-651 VP4-801 VP4-1001 VP3-1251
Suction port diameter D1 50 60 80 100 125
Discharge port diameter D2 32 40 50 65 80
Motor output kW 7.5 11 15 30 37
Sizes of principal parts A 1300 1400 1480 1700 2150
B 745 825 980 1140 1200
C 1200 1300 1400 1500 1650
D 876 961 1120 1304 1398

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This vacuum pump has a inside fluorine lining. Its thickness is 150μm or more. It covers all gas-contact parts. It was realized based on the unique technology of us. If you are having problems with corrosion of the vacuum pump, you should inquire us.


Model selection and calculation formula

How to select the model of VP Type vacuum pump

●TO select the most suitable model, inform us of the following items
1.Application Vacuum distillation, vacuum drying, PSA, vacuum furnace, extruder, etc.
2.Discharge speed (Capacity) M³/Hr、M³/min
3.Suction pressure Degrees of (normal)(ultimate) vacuum in mmHg, Torr, Pa
4.Discharge pressure Atmospheric pressure.+mmAq, kg/cm²G, etc.
5.Properties of sucked gas Composition, molecular weight, temperature, presence/absence of corrosiveness, presence/absence of toxicity, presence/absence of dust and its amount
6.Type of motor Type (Explosion proof, non-explosion proof), voltage, frequency, number of poles
7.Material of part in contact with gas Standard material, KANIGEN plating. CLEAN-S coating, SUS
8.Place of installation Indoors or outdoors
9.Other particulars Availability of cooling water and its temperature, operation time, accessories, coating color

Roots blowers

Mechanism & Features

Flow example using a high-temperature blower in the existing flow

  • 1.Root blower
  • 2.Pre cooler (200℃→70℃)
  • 3.Heater (large volumetric)
  • 4.Work space for high-temperature
  • 5.High-temperature Roots blower
  • 6.Heater (small volumetric)

Roots blowers

YOTSUBA has long been directing its efforts to the research of Roots blowers for high-pressure gas circulation and force feeding, as well as the vacuum technology. Its technology has culminated in working out the 400°C high-temperature and high-pressure gas circulation Roots blowers, unprecedented in the world. These products have thus found a home at the top of engineering that pursues energy-saving and cost performance.

Main uses

  • Gas circulation for fuel cells
  • Steam circulation for disinfecting food
  • Gas circulation for vulcanizing power cables
  • Charging a turbine
  • Steam supply for making distilled water
  • Transport of high-temperature powdered gases
  • Circulation for dehumidifying hydrogen
  • Circulation of N₂ gas
  • Steam circulation for drainage in papermaking
  • Circulation of the reactant gas
  • N₂ gas circulation for purging
  • Circulation of various high-temperature and high-pressure gases for laboratory use
  • Mechanical booster for high-temperature gas
  • Vacuum pump for high-temperature gas



  • FLB-NO.8
  • FLB-No.4(FC250)
  • MR・FLB-No.4
  • FLB-No.4
  • FLB-No.5
  • FLB-No.12
  • FLB-No.2
Model FLB-NO.8
Material SCS13(SUS304) Suction Pressure 5kPa・G
Contens Water cooling・Mechanical seal Delivery Pressure 40Kpa・G
Suction Gas N2 Power 37kW
Discharge speed 30㎥/min Use Transportation gas

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Model FLB-No.4
Material FC250 Suction Pressure 0kPa・G
Contens Grand packing Delivery Pressure 30kPa・G
Suction Gas 100℃Water Vapor Power 7.5kW
Discharge speed 4.5㎥/min Use Drainnage

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Model MR・FLB-No.4
Material FCD500 Suction Pressure 147kPa・G
Contens Two steps of High pressure booster Delivery Pressure 401.9kPa・G
Suction Gas N2gas Power 37kW
Discharge speed 7.2㎥/min Use Transportation gas

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Model FLB-No.4
Material FCD500 Suction Pressure 2MPa・G
Contens high-temperature and high-pressure booster Delivery Pressure 2.2MPa・G
Suction Gas 210℃N2gas Power 15kW
Discharge speed 1㎥/min Use Vulcanized rubber

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Model FLB-No.5
Material Niresist Suction Pressure 2.47MPa・G
Contens High-temperature and high-pressure Delivery Pressure 2.67MPa・G
Suction Gas 400℃ coal gas Power 37kW
Discharge speed 1.2㎥/min Use Circulation of gas

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Model FLB-No.12
Material FCD500 Suction Pressure 0.9MPa・G
Contens High-temperature and high-pressure Delivery Pressure 0.99MPa・G
Suction Gas 300℃ steam Power 132kW
Discharge speed 32㎥/min Use Steam circulation

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Model FLB-No.2
Material FCD500 Suction Pressure 0.3kPa・G
Contens High pressure booster Delivery Pressure 3~15kPa・G
Suction Gas Exhaust gas Power 5.5kW
Discharge speed 0.25㎥/min Use Exhaust gas treatment

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Special type Roots blowers

Special type Roots blowers for high-temperature and high-pressure gas/steam gas force feeding for new-generation fuel-cells by exploring unlimited possibilities in high-temperature and high-pressure technologies

YOTSUBA has long been directing its efforts to the research of Roots blowers for high-pressure gas circulation and force feeding, as well as the vacuum technology. Its technology has culminated in working out the 450°C high-temperature and high-pressure gas circulation Roots blowers, unprecedented in the world, which are now used as gas circulation blowers for fuel cells and in the high-pressure force feeding of various types of catalysts, among many other applications. These products have thus found a home in the top engineering that pursues energy-saving and cost performance.

  • High-temperature & high-pressure steam force feed blower
  • Fuel cell gas blower
  • Steam blower
  • High-pressure N2 gas circulation unit
  • High-pressure booster
Model FLB-No.12
Suction pressure 0.7MPa・G Delivery pressure 0.8MPa・G
Fluid 320°Csteam Capacity 42m³/min

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Model MR.FLB-No.4
Suction pressure 0.27MPa・G Delivery pressure 0.4MPa・G
Fluid 190°CN2+H2 Capacity 2m³a/min

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Model FLB-No.4
Suction pressure 0.19MPa·G Delivery pressure 0.24MPa・G
Fluid 250°Csteam Capacity 6m³/min

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Model FLB-No.2
Suction pressure 0.94MPa·G Delivery pressure 0.97MPa·G
Fluid 70°CN2 Capacity 1m³/min

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Model FLB-No.4
Suction pressure 1.12MPa·G Delivery pressure 1.32MPa·G
Fluid 70°CN2 Capacity 1.5m³/min

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Magnet coupling-Blower series

This blower does not gas leak. Because, it is without shaft-seal. Drive-shaft is driven by magnetic-coupling. It combines the safety and reliability.

Generally, a driving shaft passes through inside a casing to transfer a driving power, which must provide shaft sealing's (mechanical-seal, oil seal and etc. ) to seal inside gases.
Such sealing's can not avoid a league problem by abrasion and other troubles.
To keep away the leakage problem, instead of sealing parts (mechanical-seal and etc. ), a partition wall can solve.
A magnet on the outside of a partition wall transfers the force to a driving shaft inside.
Therefore, shaft sealing's do not provide and there are not any leakage problems. This is the best feature of a magnetic coupling blower. This nonleakage feature has reliability and safety.
A magnetic coupling loses a magnetic power by overheating.To solve the problem, our original cooling construction is provided. ( patented )
To protect a synchronized deviation, a motor shall be by an inverter drive.
Also, a period of maintenance time can be extended, since a life of a magnetic coupling is much longer than it of a mechanical seal and oil seal by abrasion.
Sample : transfer and suction of gas and material non-leakage allowed Line-up FLB type blower, 2.2 kW Please contact us about the details.

The Roots-type multistage compressor


The Roots-type multistage compressor is the most suitable for various gases! It is realized both the pressure feed and the inhalation at the same time . Maximum discharge pressure 0.3MPaG available.

VP1series The casing and rotor are water-cooled

It can be used for any application

his blower that goes beyond common sense.
Pumping, suction, boosting, vacuum, compression, anything
The gas contact parts:Can be manufactured with stainless steel, special materials, PFA lining, etc.

ICapacity adjustment (0 to 100%) by rotation speed control, suction port closing operation are also possible.※1
If you can't find the right equipment for application, you should consider our products.
It can handle various gases and corrosive gases.

Corporate Profile

Company profile for exhaust gas treatment

Name of company Yotsuba Air Machine Manufacturing Co., Ltd
Established August 1, 1973
Capital 80,000,000 JPY
Representative President Masaru Kambe
Address Main office & factory:Tobu Industrial Park, 2-15-8 Akahori, Okegawa City,Saitama Prefecture, Japan[Map]
Telephone (Main office& factory) +81-48-728-4439
Sales Division +81-48-728-4410
FAX 048-729-2400

Second factory(Materials Dept.): 2-39-9 Kamihideyaminami, Okegawa City,Saitama Prefecture, Japan[Map]
Telephone (Second factory) +81-48-714-2063
Line of business Manufacturing and sales of FLB type rotary blowers Manufacturing and sales of VP and VMP type Roots-type dry vacuum pumps Manufacturing and sales of high-temperature/high-pressure rotary blowers
Bank Saitamaken Shinkin Bank Okegawa Branch, Misashino Bank Okegawa Branch, Mizuho BankUrawa-Chuo Branch


August,1973 Began as a specialized manufacturer of rotary blowers in Urawa City, SaitamaPrefecture.
July,1982 Successfully manufactured and delivered the high-temperature and high-pressure booster, the first as a rotary blower.
June, 1983 Signed a sales contract for rotary blowers with Ebara Corporation.
March,1984 Successfully manufactured and delivered the first Japanese-made gas circulation blower for fuel cell.
July, 1985 Launched the VP and VMP series of Roots-type dry vacuum pump.
September,1990 Successfully developed the stainless steel dry Roots-type dry vacuum pump and began its sales.
May, 1994 Developed and delivered a Roots-type dry vacuum pump with a gum metal rotor for explosion protection.
June, 1996 Developed and delivered a large vacuum pump for PSA (VP3-2501).
March, 1998 Relocated to the current address and began operation.
December,2005 Added a new company premise.
March,2009 Technology partnership with the company in Chongqing, China.
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