Palladium-Silver Capillary
Overview
The palladium-silver capillary is a high-precision thin-walled tube made of palladium-silver alloy (commonly Pd75Ag25, Pd77Ag23). Its core advantages include strong hydrogen permeability, resistance to hydrogen embrittlement, corrosion resistance, and high dimensional accuracy. It is mainly used in the production of high-purity hydrogen, microfluidics, and precision instruments.
Core features
● Alloy composition: Typical Pd75Ag25 (75% palladium, 25% silver), silver enhances ductility and resistance to hydrogen embrittlement while reducing costs.
● Key performance:
◎ High hydrogen permeability: Only allows hydrogen to pass through at high temperatures, with separation accuracy reaching 99.9999%.
◎ Resistance to hydrogen embrittlement: Silver inhibits the hydrogen embrittlement of palladium, resulting in long service life.
◎ Corrosion resistance: Resistant to acids, alkalis, and high-temperature oxidation, suitable for harsh conditions.
◎ Precision dimensions: Outer diameter tolerance ±0.003 mm, wall thickness ±0.005 mm, smooth inner and outer walls
Common size (customizable)
OD: 0.30 – 8.0 mm (commonly 0.4/0.5/0.6/1.0 mm).
WT: 0.01 – 0.5- mm
Length: Customized as per requirements, common range is 200 – 500 mm.
Main applications
1. High-purity hydrogen purification: Electrolysis of water / ammonia decomposition to produce hydrogen, diffusion purification using palladium-silver tubes, with a purity of up to 6N level, used in semiconductors, fuel cells, and laboratories.
2. Microfluidics / precision instruments: Control of trace fluids for chromatography, mass spectrometry, sensors, and medical analysis equipment.
3. Chemicals and energy: Membrane reactors, high-temperature catalysis, hydrogen separation and recovery, nuclear energy-related systems.
4. Electronics and aviation: Precision electronic components, micro-pipes and sensing components for aerospace.
Selection Key Points
1. Specify the alloy ratio (e.g. Pd75Ag25), outer diameter / wall thickness / length tolerance.
2. Pay attention to hydrogen permeation flux, temperature resistance (commonly 300–500℃), pressure resistance, and surface finish.
3. Choose a supplier with precise drawing and testing capabilities to ensure batch consistency.
