Description
This page covers larger-format tube — not capillary-scale — with multiple parallel bores through one tube body, most commonly for thermocouple, gas or fluid routing through a single process-tube assembly.
Dimensions
| Parameter | Example / Specification |
|---|---|
| Bore count | 2, 4, or custom count |
| Example — 4-port furnace tube | Central gas port OD 22.5 mm / ID 20 mm; four thermocouple ports each OD 18 mm / ID 15 mm; positioned 90° apart around a central tube OD 238 mm / ID 220 mm |
| Example — double-bore process tube | Outer tube OD 68 mm / ID 64 mm surrounding an inner tube OD 46 mm, split-section, with thermocouple and heating-wire ports at specified axial positions |
| Bore diameter | Per drawing, matched to thermocouple, gas-line or fiber diameter |
| Pitch / port position | Per drawing |
Configuration
- Center-plus-surrounding-ports: central gas/process bore with multiple smaller thermocouple or gas-injection ports, commonly arranged at 90° or 120° spacing.
- Coaxial double-bore: an inner tube nested inside an outer tube, creating an annular space plus the inner bore for dual-zone thermal profiling or combined gas delivery.
- Side-by-side multi-bore: parallel bores through one tube cross-section for independent channels.
Application
- Thermocouple protection — individual bores isolate thermoelements and support accurate process-temperature monitoring.
- Multi-gas or multi-fluid delivery — independent channels for simultaneous gas or liquid delivery in CVD, inert-gas or chemical systems.
- Combined process + monitoring — one bore for process gas with additional bores for thermocouples or sensors in the same assembly.
Material
Standard clear fused quartz (Type I / GE214-equivalent); material grade can be selected from the same fused-quartz grade system used for general Quartz Glass Tubes.
FAQ
What’s the difference between this page and Multi-Hole Capillaries?
Scale and application. This page covers larger-format tube used for thermocouple, gas or process routing in equipment. Multi-Hole Capillaries covers small precision capillary tube for fiber, flow or analytical-channel applications.
Can bore diameters differ within the same multi-bore tube?
Yes. A central process bore and smaller surrounding thermocouple ports can be specified at different diameters on the same drawing.
Is a coaxial tube-within-tube configuration available?
Yes — where the design uses an inner tube nested inside an outer tube, the inner bore and annular space are specified together.