Pyrex^® Bell Jars

Pyrex Bell Jar Package Features

• Made from Pyrex to withstand thermal shock and chemical attack.
• Bottom of bell jar is ground flat to accept an L-gasket for sealing to our baseplates, feedthrough collars, or service wells.
• Inexpensive and transparent.
• Features good high-vacuum properties.
• Available in various diameters and lengths.
• Please note, although made of Pyrex, these are not designed for high optical transmission and they must be used with a guard, so are not suitable for applications where visibility and temperature measurements using optical pyrometry are required.

Bell Jar Packages

Also available as a cost effective package including the Bell Jar, Guard and Buna L-gasket, reducing cost and handling when bought together.

Packages Contents

* A Buna L-gasket is included at no additional cost. For applications where Buna is unsuitable, please order Flourocarbon or Silicone L-gaskets separately (see Pyrex Bell Jar L-Gaskets tab).

Inspecting and Using Pyrex Chambers

• When receiving a glass chamber, immediately look for shipping damage. Any glass chamber will have a variety of small imperfections. We recommend you ignore small surface scratches and bubbles (either flattened and elongated, or tiny spheres) because they are difficult to avoid in manufacturing and handling thick glass, and will not adversely affect vacuum applications.
• It is possible for there to be some marks from manufacturing that distort the optical transmission of the glass.
• Do not ignore cracks, particularly those causing a distinct dark line more than an inch long in the bulk of the glass. A crack suggests shipping damage. If undamaged, re-pack the glass chamber in its original box until ready for installation. If you find damage, please contact us immediately for further instruction. We will do everything we can to rectify the situation.
• During use, examine the glass chamber regularly for clouding, cracks, star formations (caused by point impact) or deep, long scratches. Clean the external surface using commercial glass cleaners. If the process clouds the internal surfaces, seek advice on the best method to remove the deposit. But remember, if you are depositing some "inert" or hard-coating material on a substrate, it will form an inert, hard layer on the glass. Do not compromise the vacuum by using cleaners that cannot wash away with water or clean solvent.
• Never allow hydrogen fluoride (HF) near the glass chamber. It attacks glass, causing it to become opaque. Never use harsh abrasive, wire brushes, files, or metal scrapers on the glass surface. If the glass chamber becomes cracked or scarred, discard it immediately.

Compatible Parts By Part Number

Bell Jar Guards

• For safety reasons, a bell jar guard must be purchased and used with all Pyrex bell jars. The recommended guard can be found under the compatible parts menu of each part, along with the recommended L-shaped gasket.
• Glass chamber guards limit the size of glass shards that might be projected through the air following an implosion. They also help protect the chamber from accidental damage caused by outside contact.
• All guards come with a lifting point on the center of the chamber. The combination of glass chamber and guard can then be lifted as a unit from the base plate for maintenance or modification.
• While a hoist is not necessary for small diameter glass chambers, we strongly recommend one for mid- to large-sized glass chambers to lessen the chance of injuries and equipment damage.
• Guards come with included adhesive strip to aid in lifting the bell jar with the cage. These need to be applied at the bottom and at the top of cylindrical section of the bell jar.

Pyrex Bell Jar L-Gaskets

The bell jar sits inside the riser of the "L" and is sealed by atmospheric pressure pushing it down onto the horizontal surface.

Designed to fit over the outer surface of the pyrex chamber.

Bell Jar Gaskets

Bell jar and cylinder gaskets have an "L-shaped" cross-section. The bell jar sits inside the riser of the "L" and is sealed by atmospheric pressure pushing it down onto the horizontal surface. The lower side of the horizontal surface creates a vacuum-tight seal against the sealing surface (usually a baseplate, service well, or feedthrough collar). To ensure a good seal, many users lubricate the bell jar gaskets with Apiezon^® hydrocarbon grease or Dow Corning silicone grease.

Dimensional Drawings