Description
Welch 1399 DuoSeal Belt Drive Vacuum Pump Dayton 4K929 1/3 HP 115/230V
Belt-driven rotary vane vacuum pump with 1/3 HP capacitor start motor. Operates at 1725 RPM and produces vacuum for laboratory and industrial applications.
Specifications & What's Included
- Model: Welch 1399 DuoSeal; Motor: Dayton 4K929
- 1/3 HP, single-phase AC motor, 1725 RPM, 60 Hz
- Voltage: 115/230V AC (currently wired for 115V)
- Current: 6.8A at 115V, 3.4A at 230V
- Motor frame size 48; Class A insulation
- Oil drained and not included
Applications
The Welch 1399 series is a standard laboratory vacuum pump used in scientific and industrial settings for evacuation of closed systems, degassing, and general vacuum applications. Commonly found in research labs, quality control departments, and manufacturing facilities. Belt drive design allows for flexible speed adjustment and reduced noise compared to direct-drive units.
Condition: Used
This Welch 1399 DuoSeal Belt Drive Vacuum Pump has been tested and is in working order — it powers on and produces a vacuum. It is currently wired for 115 VAC operation and can be rewired for 230V use. As with any used vacuum pump of this age, it will likely need servicing (seal replacement, oil refresh, etc.) before it meets original manufacturer specs. Oil has been drained and is not included. The unit shows general wear consistent with lab use, including paint scuffs and surface marks on the base and housing, as visible in the photos. Please view our photo set and contact us if you have any questions.
This Welch 1399 DuoSeal Belt Drive Vacuum Pump has been tested and is in working order — it powers on and produces a vacuum. It is currently wired for 115 VAC operation and can be rewired for 230V use. As with any used vacuum pump of this age, it will likely need servicing (seal replacement, oil refresh, etc.) before it meets original manufacturer specs. Oil has been drained and is not included. The unit shows general wear consistent with lab use, including paint scuffs and surface marks on the base and housing, as visible in the photos. Please view our photo set and contact us if you have any questions.
Warranty Information
We stand behind every item we sell with a 30-day money-back guarantee. If your item arrives not as described, you may return it within 30 days for a full refund. Please inspect your purchase upon arrival and contact us with any questions.
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Additional Information
Brand: |
Welch |
Model: |
1399 |
MPN: |
1399 |
Type: |
Belt Drive Rotary Vane Vacuum Pump |
SKU: |
47981 |
Motor Brand: |
Dayton |
Motor Model: |
4K929 |
Motor Type: |
Capacitor Start A.C. Motor |
Horsepower: |
1/3 HP |
Voltage: |
115/230V AC |
Current Rating: |
6.8A (115V) / 3.4A (230V) |
Speed: |
1725 RPM |
Frequency: |
60 Hz |
Phase: |
Single Phase |
Motor Frame: |
48 |
Insulation Class: |
Class A |
Drive Type: |
Belt Drive |
Current Wiring: |
115 VAC |
Pump Series: |
Duo-Seal |
Manufacturer: |
Sargent-Welch Scientific Co., Skokie, Illinois |
Condition: |
Used – Tested and Working |
Seller Notes: |
Oil drained and not included. Currently wired for 115V. May need service to reach full factory specs. |
Country/Region of Manufacture: |
United States |
Form Factor: |
Benchtop / Base-Mounted |
Application: |
Laboratory, Scientific, Industrial Vacuum |
Review Status: |
Auto-Approved (needs review) 2026-07-04 |
Condition Notes: |
Welch 1399 DuoSeal Vacuum Pump tested and in working order — powers on and produces vacuum. Wired for 115V; can be rewired for 230V. Will need servicing to reach factory specs. Oil drained, not included. Shows typical lab wear. |
