Built for Demanding Lab and Industrial Use
The Welch DuoSeal Model 1399 is a belt-driven, oil-sealed rotary vane vacuum pump designed for continuous operation in environments where reliability and low maintenance matter. With a pumping speed of 140 L/min and an ultimate pressure of 1 x 10⁻⁴ Torr, it’s engineered for high-throughput, high-reliability applications like vacuum ovens, freeze drying, and glove boxes.
This model is part of Welch’s long-standing DuoSeal line, known for its rugged construction and long service life. The 1399 is oil-lubricated and features a two-stage design that delivers deep vacuum levels while maintaining quiet operation and minimal vibration.
Key Features
- Pumping Speed: 140 L/min (5.0 CFM)
- Ultimate Vacuum: 1 x 10⁻⁴ Torr
- Motor: 1/2 HP, TEFC, 115/230V, 60Hz
- Oil Capacity: 1.25 quarts
- Noise Level: ~52 dB(A)
- Weight: 85 lbs (38.5 kg)
- Inlet/Outlet: 3/4" NPT
Common Use Cases
- Freeze dryers
- Vacuum ovens
- Glove boxes
- Vacuum manifolds
- Laboratory filtration systems
FAQs
Use Welch DuoSeal vacuum pump oil or equivalent high-grade mineral oil with low vapor pressure. Refer to the manual for viscosity and compatibility details.

