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RUVAC WSU 251 3Ph 200/230/400 V 50 Hz, 200-208/265/460 V 60 Hz; Mineral oil LEYBONOL LVO 130, integral leak rate < 1 × 10⁻⁵ mbar·l/s

Part number: 155009 Series: RUVAC WS/WSU series Manufacturer: Leybold Technology: Roots vacuum pumps

The Leybold RUVAC WSU 251 is an air-cooled Roots vacuum pump with a hermetically sealed canned motor and integrated pressure equalisation line: 253 m³/h nominal pumping speed at 50 Hz, 210 m³/h maximum effective pumping speed and 1.1 kW motor power. Ehrler & Beck supplies the RUVAC WSU 251 in four variants with matching accessories, spare parts and service.

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  • Pumping speed 210 m³/h 50 Hz 251 m³/h 60 Hz
  • Ultimate pressure 8 × 10-4 mbar
  • Rated motor power 1.1 kW 50 Hz 1.4 kW 60 Hz
Available variants
Variant Part number
3Ph 200/230/400 V 50 Hz, 200-208/265/460 V 60 Hz; Mineral oil LEYBONOL LVO 130 11723
3Ph 200/230/400 V 50 Hz, 200-208/265/460 V 60 Hz; Mineral oil LEYBONOL LVO 130, TE version (CE) 11723TE
3Ph 200/230/400 V 50 Hz, 200-208/265/460 V 60 Hz; PFPE LEYBONOL LVO 400 11728
3Ph 200/230/400 V 50 Hz, 200-208/265/460 V 60 Hz; Mineral oil LEYBONOL LVO 130, integral leak rate < 1 × 10⁻⁵ mbar·l/s (selected) 155009

Leybold RUVAC WSU 251 – Roots pump with canned motor and 253 m³/h nominal pumping speed

The RUVAC WSU 251 corresponds to the WS 251 but additionally has an integrated pressure equalisation line with differential pressure valve. It can therefore be started together with the backing pump at atmospheric pressure and is suitable for short pump-down cycles. For particularly leak-tight systems, Leybold offers a version with an integral leak rate below 1 × 10⁻⁵ mbar·l/s. The nominal pumping speed is 253 m³/h at 50 Hz and 304 m³/h at 60 Hz, the maximum effective pumping speed 210 and 251 m³/h respectively. The pump measures 694 × 305 × 300 mm, weighs 95 kg and is connected via DN 63 ISO-K; the noise level is below 63 dB(A).

Typical applications

The RUVAC WS/WSU work as boosters in front of an oil-sealed or dry backing pump. Leybold recommends the canned-motor series for applications requiring a high pumping speed between 10⁻² and 10⁻⁴ mbar, for processes in which neither air may enter nor pumped medium escape, and for the extraction or transfer of high-purity gases. Typical applications of the RUVAC series are heat treatment and furnace construction, metallurgy, large-area coating, load-lock chambers and crystal pulling systems for the semiconductor and solar industries.

Variants of the RUVAC WSU 251

The RUVAC WSU 251 is available from Ehrler & Beck in four variants (part numbers 11723, 11723TE, 11728, 155009). All variants have the same canned motor with a motor power of 1.1 kW at 50 Hz to 1.4 kW at 60 Hz for mains voltages from 200 V to 460 V. They differ mainly in the oil filling: mineral oil LEYBONOL LVO 130, PFPE LEYBONOL LVO 400.

Features of the RUVAC WS/WSU

  • Air-cooled canned motor: no shaft feedthrough to atmosphere, integral leak rate ≤ 1 × 10⁻⁴ mbar·l/s
  • Temperature monitoring in the motor's stator winding; separate fan under the fan cover
  • Operation on 50 and 60 Hz mains; higher speeds are possible with a frequency converter
  • All elastomer seals made of FPM (FKM)
  • WSU: integrated pressure equalisation line with differential pressure valve as overload protection
  • Supplied for vertical pumping direction; conversion to horizontal pumping direction possible by the customer
  • Oil filling supplied separately; inlet flange with dirt trap, pump vented with nitrogen for corrosion protection
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