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Welch™ Freeze Dryer Pumps

Special application direct-driven pump designed for harsh chemical mixtures like TFA, TFA byproducts, acetonitrile, and HBr that are removed during sample drying

Manufacturer:  Welch™ 8917A80

Catalog No. 01-257-91

This item has been discontinued by the manufacturer and is no longer available. Please call customer service for assistance: 1-800-766-7000.



Oil is continuously filtered through micron filter paper and acids are neutralized using Al2O3 pellets. The large, 1.4 qt. (1.3L) oil capacity dilutes organic vapors that mix with the pump oil during the freeze drying run. Includes DirecTorr™ Gold synthetic oil, which has excellent resistance to chemical attack.

  • Ultimate vacuum of 1 × 10-4 torr
  • Continuous acid neutralization and oil filtration
  • Large oil capacity extends service intervals
  • 1725rpm pump speed, 1/2hp
  • Aluminum UNIBARB™ style inlet connector accepts two sets of tubing I.D. (7/16 and 13/16 in. [11 and 20mm]) and has a screen
  • Exhaust connector has a 1-20 thread

Order Info

Dimensions: 18 5/8L × 11 1/2W × 9 5/8 in.H (47.2 × 29.2 × 24.4cm); Net weight: 55 lb. (25kg)


115V 60Hz model is CSA approved; 230V 50Hz model is CE marked



1 x 10-4 torr
0.5 hp
1725 rpm
115 V 60 Hz
25 kg
60 Hz
24.4 cm
47.2 cm
115 V
Continuous Acid neutralization and Oil filtration
70 lb.
173 L/min.
9.6 in.
18.6 in.
11.5 in.
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