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Dolphin LB 2108 - 3108 A

Our Dolphin LB range of liquid ring two-stage vacuum pumps are well suited for wet and corrosive applications. They combine the benefits of high efficiency from a compact rugged machine, and reduced running cost from a competitive product.


  • Suction capacity from 38 cfm to over 2500 cfm
  • Ultimate pressure of 25 torr (29 HgV)
  • Available in a wide range of materials
  • Minimal moving/contacting parts allowing ease of service and
  • Single mechanical seals standard
  • Low vibration and noise level
  • Reliability
  • ANSI flanges and NEMA motors
  • Some models are directly interchangeable with other brands
  • Low heat emission
  • Oil free discharge

Dolphin – robust and compact. Ideal for difficult applications.

Would you like to know more?
Contact us directly (Busch United States):
+1 757 463 7800 Get in contact

Technical specifications
Liquid ring pumps operate with only one moving part, the impeller shaft assembly. The impeller is mounted eccentrically relative to it’s casing. The liquid ring is formed by the service liquid (normally water) rotating concentrically in it’s casing. Process gas enters through the suction port, travels between the impeller blades and is compressed prior to exhausting through the discharge port along with a quantity of service liquid.

Available Options

  • Various materials of construction including 316 stainless steel,
    bronze, etc...
  • Base plate or pedestal mounting configurations
  • IEC motors
  • Metric connections
  • System configurations (once through, partial recovery, and
    total recovery)
  • Outboard bearing in place of standard inboard bearing
  • Packed gland seal or double mechanical seal

System Configurations
1. Once Through System - No Recovery
The service liquid comes from a fresh supply, passes only once through the pump and is discharged to an open drain.

2. Partial Recovery System
Within this system the service liquid is discharged to a vessel which allows separation of the gas and liquid. A portion of the discharged liquid is returned to the pump’s service fluid inlet together with a fresh liquid supply. This reduces the amount of fresh liquid required.

3. Total Recovery System
This system provides for total recirculation of the service liquid and is preferable when liquid is in short supply or where there is a risk of contamination. A heat exchanger is added to the system to remove the heat of compression prior to re-use of the service liquid.

Dolphin LB 2108 - 3108 A
Dolphin LB 2108 - 3108 A
Pumping speed

Air at 70 ºF. Tolerance: ± 10%

60 Hz
Pumping speed
Technical data Dolphin LB 2108 A Dolphin LB 2508 A Dolphin LB 3008 A Dolphin LB 3108 A
Nominal pumping speed ACFM 60 Hz 1368 1813 1889 2063
Ultimate pressure Torr 60 Hz 25 25 25 25
Nominal motor rating HP 60 Hz 125 150 200 200
Nominal motor speed RPM 60 Hz 880 880 880 880
Noise level (ISO 2151) dB(A) 60 Hz 79 79 79 79
Weight approx. Lbs. 3219 3483 3748 4277
Dimensions (L x W x H) inches 76 5/16 x 25 9/16 x 39 7/16 82 3/16 x 25 9/16 x 39 7/16 86 1/8 x 25 9/16 x 39 7/16 87 ½ x 25 9/16 x 39 7/16
Gas inlet / outlet (ANSI) inches 6" / 6" 6" / 6" 6" / 6" 6" / 6"

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