Vacuum System Components: Comprehensive Guide to CF Reducing Crosses

CF Reducing Crosses are essential vacuum fittings designed with ConFlat (CF) flanges, enabling high-vacuum cross-connections between different pipe sizes. Ideal for semiconductor, research, and aerospace applications.

Product Overview

CF Reducing Crosses are specialized vacuum fittings that connect pipelines of different diameters in a cross configuration. Designed with ConFlat (CF) flange standards, they offer:

Multi-directional flow control: Enables 4-way vacuum connections for gas/liquid distribution

UHV compatibility: Maintains integrity in ultra-high vacuum environments (10⁻⁹ Pa and above)

Size adaptability: Solves complex piping challenges with precision reducing connections

Widely used in semiconductor processing, particle accelerators, space simulation chambers, and thin-film deposition systems.

Construction Details

1. Cross Body Assembly

Material: High-purity stainless steel (304L/316L) for corrosion resistance

Configuration: Four ports arranged perpendicularly with reducing diameters

2. CF Flange Connections

Standard ConFlat flanges at all ports

Knife-edge design for metal gasket sealing

Compatible with NW/KF systems via adapters

3. Sealing System

Gasket material: Oxygen-free copper (standard) or aluminum for special applications

Installation: Captive design ensures proper alignment during assembly

Key Features

Ultra-high vacuum performance (10⁻⁶ to 10⁻¹⁰ Pa range)
Precision reducing connections between different flange sizes
Helium-leak tight metal seal construction
Corrosion-resistant stainless steel body
Thermal stability (-200°C to +450°C with proper gasket selection)
Vibration-resistant design for dynamic applications

Industrial Applications

Semiconductor: Etching systems, CVD reactors, ion implanters

Research: Synchrotrons, mass spectrometers, surface science instruments

Aerospace: Satellite test chambers, propulsion system simulators

Industrial: Vacuum furnaces, analytical instruments, coating systems

Technical Specifications

CF Reducing Crosses FAQ

1. What vacuum levels do CF flange fittings support?

Rated for UHV/XHV applications from 10⁻⁶ to 10⁻¹⁰ Pa when properly installed with copper gaskets.

2. How to select gaskets for vacuum system components?

OFC copper: Standard UHV applications

Aluminum: For cryogenic or high-temperature cycles

Silver-plated: Best for bake-out systems

3. Installation tips for high-vacuum cross fittings?

Clean flanges with IPA before assembly

Use crisscross bolt tightening pattern

Apply recommended torque values (typically 8-12 Nm)

4. Can reducing vacuum connectors be customized?

Yes - available options include:

Special materials (Hastelloy, titanium)

Non-standard size combinations

Additional ports or instrumentation taps

5. Are semiconductor vacuum equipment fittings corrosive gas compatible?

316L stainless steel models resist most process gases. For aggressive media:

Specify electropolished finish

Consider nickel plating

6. Leak testing methods for research vacuum parts?

Helium mass spectrometry: Most sensitive (detects to 10⁻¹² mbar·l/s)

Pressure rise test: Simple quality check

7. Temperature limits for spacecraft vacuum testing fittings?

Standard: -200°C to +200°C

High-temp versions: Up to +450°C with special gaskets

8. Maintenance of stainless steel CF flange joints?

Replace gaskets after each disassembly

Inspect knife edges annually

Keep spares for critical systems

9. Failure modes in ultra-high vacuum seals?

Gasket over-compression

Particulate contamination

Thermal cycling damage 

10.Extending service life of thin-film coating equipment fittings?

Implement proper bake-out procedures

Use load-spreading washers

Store with protective caps when not in use