Products
Vacuum Pumps
Belt Driven PumpsDuoSeal 1374DuoSeal 1376 DuoSeal 1376B-46DuoSeal 1380DuoSeal 1397 DuoSeal 1397B-46DuoSeal 1399DuoSeal 1400DuoSeal 1402DuoSeal 1402B-46 DuoSeal 1405DuoSeal 1400W-01DuoSeal 1402W-01DuoSeal 1405W-01ChemStar 1400N-90ChemStar 1402N-90ChemStar 1376NChemStar 1400NChemStar 1402NCapture CRRBelt Kit 1397ABelt Kit 1399ABelt Kit 1400ABelt Kit 1405AMajor Repair Kit 1373K-06Major Repair Kit 1376K-06Major Repair Kit 1376K-10Major Repair Kit 1380K-04Major Repair Kit 1397K-08Major Repair Kit 1399K-04Major Repair Kit 1400K-04Major Repair Kit 1400K-10Major Repair Kit 1402K-06Major Repair Kit 1402K-10Major Repair Kit 1402K-47Minor Repair Kit 1373K-05Minor Repair Kit 1376K-05Minor Repair Kit 1376K-09Minor Repair Kit 1376K-46Minor Repair Kit 1397K-07Minor Repair Kit 1380K-03Minor Repair Kit 1399K-03Minor Repair Kit 1400K-03Minor Repair Kit 1400K-09Minor Repair Kit 1402K-05Minor Repair Kit 1402K-09Minor Repair Kit 1402K-46Seal Kit 1401EDuoSeal Oil
Vacuum Gauges and Controllers
Vacuum Pump Oils
Applications
Mass Spectrometry
Botanicals Processing
HVAC Pumps
Rotary Evaporator
Vacuum Concentrator
Vacuum Manifold
Freeze Dryer
Vacuum Oven
Vacuum Filtration
Vacuum Distillation
Aspiration (Cell Culture)
Glove Box
Gel Dryer
Vacuum Measurement & Control
Pick & Place
Vacuum Workhholding
Degassing / Dessicator
Vacuum Leak Detection: Methods, Tools & Tips
Service
Maintenance Kits
FAQ
About Us
News
Careers
History
Our Values
Downloads
Knowledge Base
Discover & Learn
Install & Setup
Operate & Maintain

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.

Full Product Manual

For detailed specifications, maintenance procedures, troubleshooting steps, and exploded diagrams, download the official Welch DuoSeal Model 1399 manual.
DuoSeal Vacuum Pump Model 1399

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.