Specialty Chambers & Related Supplies

Here I have listed several economical HVAC-type vacuum pumps that may be purchased directly from Amazon.com.
The rest of the list consists of accessories and chambers that may be purchased direct from the Bell Jar. This list will grow over time. Purchases for these items made be made through my PayPal shopping cart or you may pay by check by adding the individual item prices and computing shipping using the chart at the bottom of the page.


Pumps and Pump Accessories

Manifold and Chamber Adapters

Phosphor Screens

Standard Glass Chambers

Custom Designed Glass Tubes & Chambers

Ordering and Shipping Terms

Refrigeration HVAC Service Pumps & Accessories

Back in the 1990s I had provided a Robinair pump with inlet hose adapter. I sold a number of these but the logistics of purchase and reshipment, combined with the modest markup that I charged, just didn't make the effort worth it. Today these pumps are much more readily available and there are many more suppliers. Another trend is toward very low cost pumps of Chinese manufacture.

There are a number of good pumps that I am familiar with that represent good values and are offered through Amazon. I have selected a few for this list. One is the Robinair 15600, a nicely built 2-stage 6 cfm pump that is manufactured in Minnesota. I have used Robinair pumps for years and have never had a problem that wasn't self inflicted. With clean oil I have measured 10 mTorr at the inlet.

The second pump is a single stage 5 cfm pump of Chinese manufacture that is distributed by Advanced Tool Design (ATD) as their model ATD-3425. This pump is inexpensive but robust and easy to work on. This pump is good for applications such as vacuum deairing and laminating. I have recently prepped one for pumping oxygen plasmas for a plasma stripping project. This involved disassembing and degreasing the pump and refilling with inert fluid.

The third pump is a very low cost 3 cfm single stage pump with a rock bottom price and very good specs.

Below are listings for these pumps and replacement oil. I have also listed a number of components to adapt these pumps to standard vacuum hose. These items may be ordered through Amazon.

Please also see the article HVAC Vacuum Pump Manifold & Chambers for more information on outfitting the Robinair pump.

  The Robinair15600 is a two stage design with 6 cfm capacity and 20 milliTorr rated base pressure. Other features include 1/2 hp motor, inlet isolation valve, gas ballast and 1/4" and 1/2" SAE MFL (flare) inlet fittings. The manual may be found in PDF format here.

The ATD-3425 is a simple single stage pump of Chinese manufacture. Free air capacity is 5 cfm and the rated base pressure is 200 milliTorr (Amazon's copy is in error). Other features include 1/3 hp motor, gas ballast and 1/4" SAE MFL and 1/2" ACME inlet fittings. There is no inlet isolation valve. The manual may be found in PDF format here.

  The FJC 6909 is a relative newcomer. This is another single stage pump of Chinese origin. There are two outstanding features of this pump: the price and the achievable pressure. I had a hard time believing the ca. 80 micron claim so I purchased a relative of this pump (basically the same pump but under a house label). With a small manifold and glass chamber attached it quickly got to less than 80 microns. These seem well constructed and I equipped a client with one to use with a portable teaching system. Fittings are the same as with the ATD-3425.
  32 oz high quality direct drive vacuum pump oil. Keep your pump clean and performing well by regularly changing the oil.


1/2" MFL to 1/2" Hose Fitting Adapter HF50

This stainless steel fitting will adapt a 1/2" flare fitting to 1/2" inside diameter pvc vacuum hose. Included with the fitting are three copper flare gaskets. This works very well with the Robinair 15600.

$14.00 each


1/4" MFL to 3/8" Hose Fitting Adapter HF38

This stainless steel fitting will adapt a 1/4" flare fitting to 3/8" inside diameter pvc vacuum hose. Included with the fitting are three copper flare gaskets. This works well with the ATD-3425 and many other HVAC pumps.

$10 each


Steel Spring Reinforced PVC Vacuum Hose

5 foot length of either 3/8" id or 1/2" id vacuum hose. Comes with 2 hose clamps.

HO38 (3/8" inside diameter): $15.00

HO50 (1/2" inside diameter): $18.00

Manifold and Chamber Adapters

Please also see the article HVAC Vacuum Pump Manifold & Chambers for more information on the use of these components.

Mating flanges and related hardware (center rings and clamps) may be ordered from Kurt J. Lesker Company. I highly recommend the use of a screened KF40 center ring to prevent debris and/or charged ionic species from entering the pump or gauge.


Inlet Manifold for Robinair Pump PM50

This fitting turns your Robinair pump into a complete vacuum system ready for your gauge and chamber. The bottom has a 1/2" SAE flare adapter that mates directly to the pump. There are two side ports: one has a needle valve that can be used for pressure control and inert gas inlet. The other side has a KF16 flange that can be used with Bourdon or thermal conductivity gauges. At the top is a KF40 flange that is used as a standard attachment point for your chambers.

Inquire about pricing


1-3/8" Tube Adapter TA138

This fitting will adapt the KF40 flange of the PM50 to 1-3/8" glass tubing and represents the standard vacuum interface for my vacuum tubes and chambers. It consists of a brass compression adapter that is tin-silver soldered to a KF40 flange. Since the flange inside diameter is a bit smaller than that of the compression adapter I open the id of the flange on a lathe to prevent the glass tubing from becoming pinched at the open end. Each adapter is tested on my vacuum stand for leak integrity.

Of course, this adapter may be used with any KF40 equipped manifold.

Inquire about pricing

Phosphor Screen PH04

This is plastic encapsulated professional grade Zn-CdS fluoroscope phosphor. Flexible, easy to handle and robust, this material can be cut to smaller sizes with scissors. Bright green fluorescence with moderate persistence, it is sensitive to electrons and x-rays. It may be used within vacuum systems in the medium to upper high vacuum ranges. Can be cleaned with soap and water and surface deposits may be removed with a 3M Scotchbrite pad. Cut size is about 1.9 inches on a side. Supplied with a copy of the MSDS. (Note, contains cadmium. Take care to avoid inhaling dust when cutting. Wash hands after handling.)

$18.00 per sheet

Standard Glass Chambers

In this line of tubes and chambers I am developing a series of glass apparatus that will be useful to the hobbyist and educator. The line is based on two specific features. First, all tubes will connect to the vacuum system via a 1-3/8 inch compression coupling, such as the TA138 listed above. Second, the tubes will have one or more feedthroughs based on the Ace Glass, Inc. proprietary Ace Thred. The two standard sizes will accomodate 3/8" and 1 inch diameter rods. The principle of the Ace Thred is shown in the figure below. The thred itself is a molded connector of borosilicate glass. The glassblower attaches this connector to the apparatus as the desired locations. The other parts of the thred consist of a nylon bushing and a fluorocarbon o-ring. When assembled around an appropriately sized rod (usually aluminum if the rod is serving as an electrical feedthrough), the tightening of the bushing compresses the o-ring between the glass connector and the rod. The bushing is not exposed to vacuum thus making the seal compatible with medium and high vacuum systems.

In vacuum apparatus it is highly recommended (essential for threds larger than 11mm) that the rod be provided with a stop of some kind. Shaft collars are very convenient although pins or hose clamps can also be used. The reason for doing this is to prevent the rod from slipping through the bushing as a result of differential pressure. A rod thus entering a vacuum chamber can quickly assume enough velocity to shatter the apparatus.

When using any vacuum device, especially glass apparatus, always wear protective eyewear and place a transparent shield (e.g. plexiglas or polycarbonate) between the apparatus and observers.

While this line is being offered as a growing set of standard designs, requests for variations are welcome. Additional guidelines are in the Custom Chambers section further down.

Classic Discharge Tube GT01

This tube represents a classic 2-electrode discharge tube. The "hot" electrode would be the one at the Ace Thred (a piece of hardware store aluminum rod will suffice) while the grounded vacuum manifold serves as the other electrode. Beautiful glow discharges can be created within the tube. Adjusting the pressure in the system will reveal how the discharge changes with pressure. Inert/non-reactive gases may also be introduced to show the colors associated with various gases. A magnet placed near the tube will show the effect of a magnetic field on the plasma.

A phosphor screen placed within the tube will help to visualize the path taken by electrons. Additional feedthroughs can be provided to demonstrate plasma diagnostics (Langmuir probe) or to provide electrostatic deflection.

Comes complete with nylon Ace Thred bushing and o-ring. Tube is selected to accurately fit the TA138 adapter.

Price: $125.00

Universal Discharge Tube GT02

This tube is in the line of the "highly exhausted" cathode ray tubes of Crookes, Lenard and Roentgen. It will be the subject of a series of articles in the 2008 volume of the Bell Jar. Its current status is unreleased, expected price will be in the $200-$230 range.

A picture of the prototype is shown below.

Custom Designed Glass Tubes and Chambers

Guidelines are being developed

Ordering and Shipping Terms

On line payments may be made with PayPal. If it is desired to pay by check please mail your order to DiverseArts, PO Box 456, 34 Meadowbrook Lane, Owl's Head, ME 04854. Be sure to include the shipping charges.

I will provide confirmation of any order received within 24 hours. Most orders will ship within 2-3 business days although that may vary as I establish appropriate inventory levels. Glass chambers will, for the time being, be made to order with expected lead time not to exceed 3 weeks.

Packing and shipping charges are additional for each order. Please see the shipping table below for the correct amount. I ship via USPS Priority Mail, for 2-3 day delivery time. Other methods upon special request (please contact us with your requirements). I promise to expertly pack your items, and never skimp on packing materials or methods.

Priority Mail,
USA Only
$0 to $100 $8.00
$100.01 to $200 $12.00
$200.01 to $500 $15.00
$500.01 to $1000 $25.00
Over $1000.00 $35.00
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