Custom Quartz Process Chambers, Bell Jars & Covers

Quartz process chambers and bell jars built as a complete assembly — body, ports, flanges, and windows — sized to your equipment or reproduced from a worn original.

Chamber dimensions, port/flange position, overall height, and weld distortion are one assembly chain — a port position shifts if the body size changes, so confirm all of them together, not one dimension at a time.

Ports, Flanges, Windows and Feedthrough Openings

Ports for gas, vacuum, or instrumentation feedthroughs are welded into the chamber wall at positions set by your equipment, not placed arbitrarily. Flanges seal the chamber to the rest of your system — ground quartz flange for an O-ring seal, or a quartz-to-metal transition where the chamber interfaces with metal equipment. Windows (for process viewing) are built into the wall or lid as a separate optical feature, with its own flatness and clarity requirement apart from the structural body.

Quartz Chamber and Bell-Jar Configurations

• Bell jar — a dome or cylindrical cover, open at the base, that seals down onto a baseplate
• Process chamber — a fully enclosed body with its own base, ports, and lid
• Cover / shroud — an open-bottom shell used as a shield or enclosure without a sealed base

Which configuration fits depends on how your equipment's base and seal are built — tell us whether the quartz part needs to seal against a metal base or is fully self-contained.

Quartz Process Chambers, Bell Jars & Covers Factory Standard & Assembly Limit

Replacing an existing chamber? Send the equipment model and, if you have it, the old part or its drawing. At minimum we need main diameter/L×W, overall height, wall thickness, and the position of every port, flange, and window — matching only the outer envelope is the most common cause of a chamber that doesn't seal or interface correctly.

Fabrication is large-format cutting and forming, port and flange welding, window/support assembly, and annealing. Before shipment we check main body dimensions, port coordinates, flange face condition, weld seams, overall warpage, and — where the project calls for it — a leak check.

Ø150–600 mmCommon Diameter Range

PortsCustom Count

FlangeEquipment Interface

WindowOptional Opening

Low OHProcess Grade Option

JGS2Optical Grade Option

Process Enclosure

Ports, Flanges and Windows Must Be Located from the Sealing Datum

Controlled Feature	Reference Capability / Requirement
Overall Size	Ø150–600 mm common quotation range; custom chamber or cover geometry by drawing
Wall Thickness	Defined from diameter, process environment and support method
Port Count / Size	Every nozzle, feedthrough and pump port listed separately
Port Position	Axial, angular and center-height dimensions referenced to a common datum
Flange Interface	Machined, welded or mating geometry defined from equipment hardware
Window / Feedthrough	Clear opening, sealing interface and orientation stated
Assembly Alignment	Flange, body and port axes checked as an assembled part
Material	Low-OH process quartz or JGS2-class optical quartz according to function

Enclosure Types

Select the Structure Before Adding Connection Details

Structure	Reference Range / Form	Primary Drawing Controls
Bell jar	Ø150–600 mm common range	Base flange, height, wall and lift method
Process chamber	Cylindrical or custom body	Ports, axes and sealing faces
Chamber cover	Flat, domed or necked cover	Seat geometry and feedthrough openings
Replacement assembly	Matched to installed equipment	Datums, port centers and mating hardware

Available Forms

Configurations Defined by the Process

Bell JarTransparent domed enclosure with controlled base interface

Multi-Port ChamberWelded nozzles positioned around a process body

Process CoverFlat or formed cover with feedthrough openings

Flanged EnclosureMachined or welded interface matched to process hardware

Applications

Vacuum and Thermal Process Equipment

Vacuum CoatingQuartz enclosures with defined ports and observation openings

Crystal-Growth EquipmentBell jars and covers matched to hot-zone geometry

Reaction ChambersMulti-port assemblies for gas, feedthrough and pumping paths

Equipment ReplacementChambers reproduced from a datum drawing or measured sample

Product Examples

Product Forms and Finished Components

Need a chamber or bell jar matched to installed equipment?Send the overall envelope, wall section, sealing datum, flange details, every port center and handling method.

Open the Product Configurator

Engineering Data

Grade-Qualified Material Purity

Electric-fused / flame-fused quartz: SiO₂ ≥99.99%; synthetic JGS1-grade fused silica: ≥99.999%. Grade and lot certificate govern supplied material.