Welch Vacuum 2042B-01 DryFast Vacuum Pump, Oil-Free Diaphragm

Product Code WELCH-2042B-01

AvailabilityOut of stock

Unit price
Shipping calculated at checkout.


  • All PTFE wetted materials
  • Perfect for high boiling point applications
  • Chemical duty
  • Convenient vacuum control
  • Easy operation and maintenance

Suggested Applications

  • Concentrator - Gel Dryer Combination
  • Rotary Evaporator
  • Vacuum Concentrator
  • Vacuum Oven

Use DryFast vacuum pumps for precise, convenient solvent evaporations without oil mess. Portable and chemical resistant, DryFast PTFE diaphragm pumps provide excellent vapor flow and the right vacuum for top application performance. Perform rotary or centrifugal evaporations in minimal time with no sample foaming or bumping.

DryFast pumps use Advanced Vapor Management (AVM) to adjust vacuum levels to exact levels needed for optimal evaporation rates. The handy AVM knob fine-tunes vacuum while purging condensates from the diaphragm to maintain efficient pumping and extended diaphragm life.
DryFast achieves top vacuum performance with only one or two pumping heads (model dependent) – a design that promotes efficiency and low maintenance. Quiet, oil-free, PTFE / perfluoroelastomer contact surfaces.

2 torr DryFast models provide deep vacuum for rotary evaporation of solvents with atmospheric pressure B.P. up to 160o C. The 35 L/min model will accommodate larger evaporation flasks up to 10L or small vacuum ovens. Use the 25 L/min model for flask evaporations to 2 L.


Product flyer

Specifications & Description

Head Configuration

Dual Heads

Wetted Parts

PTFE, Kalrez®

Free-Air Capacity (CFM)


Free-Air Capacity (LPM)


Free-Air Capacity (LPH)


Max Flow Rate (CFM)


Max Flow Rate (Liters/min)


Max Vacuum (in Hg)


Max Vacuum (mbar)


Max Vacuum (mm Hg)


Max Vacuum (torr)


Noise Level (dB)


Port Size

1/4" hose barb

Max Temperature (° F)


Max Temperature (° C)


Duty Cycle


Power (VAC)


Power (amps)


Power (Hz)


Height (in)


Length (in)


Height (cm)


Length (cm)


Height (mm)


Length (mm)





Vacuum Pump, PTFE, 2 torr, 35 L/min, 115V

Local Delivery

We offer delivery services for large orders to customers from Central California all the way to San Diego. Please call our sales team for more information on weekly, bi-weekly, or monthly deliveries and pricing. 626.332.7744


Shipping Time

Our main warehouse is located near Los Angeles, you can use the map below to estimate delivery time. Most orders ship one business day after the order is placed, then the transit days will follow. Below the map you will find exceptions to these rules for certain products.

HFS Shipping T

Some items we sell may be warehoused in Amazon's warehouses across the US. If the item you order happens to be in on of their warehouses it will generally arrive in 3 days. If you need to know about a specific item please feel free to contact us and we'll let you know.

Larger and heavier items have to be shipped via LTL Freight. LTL shipments tend to take longer to arrive, but they have the benefit of being much safer for heavy and delicate items. If your order has to be shipped by LTL Freight we will contact you to find out if the delivery address is a residential or commercial address, and whether a loading dock or forklift is available. The freight company will call you to arrange a delivery appointment, usually a day before.


Shipping Costs

The cost of shipping varies based on where you live, how much the order weighs, and the value of the order. We've outline our shipping guidelines below:

To Contiguous US:

Item Weight

Shipping Costs

0-50 lbs

Orders over $100 ship free;
Orders $99.99 and under are a $10 flat fee.

Over 50 lbs

The shipping cost will be automatically calculated by the system based on the weight of your items and the delivery address provided.


To Alaska, Hawaii, and other US Territories:

 Cost will be calculated by weight at time of checkout.

To Other Countries:
We currently can offer shipping service internationally.
Please contact us for international shipping cost: info@hfsusa.com

Welch Vacuum 2042B-01 DryFast Vacuum Pump, Oil-Free Diaphragm

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