SilcoCan Canister with RAVE Valve

Importance of Topic

Active sampling of volatile organic compounds (VOCs) in air demands inert, leak-free containers to prevent analyte loss and contamination. The SilcoCan canister with RAVE diaphragm valve delivers robust sealing and superior interior passivation, crucial for environmental monitoring, industrial hygiene, and regulatory compliance.

Objectives and Overview

This application note outlines the design features, recommended cleaning and certification procedures, and reconditioning service options for Restek SilcoCan canisters equipped with RAVE valves. It provides guidance to ensure consistent sample integrity and method compliance.

Methodology and Instrumentation

Cleaning and certification protocols follow EPA and comparable standards (TO-12, TO-14A, TO-15, among others).

• Surface Treatment: Siltek bonding of a fused silica layer to stainless steel interior reduces adsorption of polar and sulfur compounds.
• Valve Technology: RAVE diaphragm valve with metal-to-metal seat, leak tested to ≤1×10⁻⁶ mL/s; rated to 40 psig.
• Cleaning System: TO-Clean oven with oil-free dry scroll pump to achieve vacuum <0.2 mm Hg; uses humidified ultra-high-purity nitrogen; heating up to 120 °C with gauge (140 °C without gauge).
• Analytical Verification: Blank analysis by GC-MS, GC-FID, or GC-ECD confirms cleanliness prior to reuse.

Key Results and Discussion

Testing shows that:

• Siltek-treated surfaces remain inert and durable under field handling and thermal cycles.
• Vacuum cycles with humidified nitrogen and controlled heating effectively remove residual contaminants.
• Certification by re-pressurization and blank analysis verifies canister readiness for reuse.
• Optional pressure gauge enables rapid verification of vacuum or pressure status.

Benefits and Practical Applications

Users benefit from:

• Reliable capture of trace-level VOCs in ambient, industrial, and occupational environments.
• Efficient turnaround through automated cleaning aligned with regulatory methods.
• Cost-effective reconditioning service replacing valves and revalidating canisters instead of full replacement.

Future Trends and Opportunities

Emerging developments include:

• Integrated digital monitoring for real-time leak detection and process tracking.
• Advanced surface chemistries to extend inertness to highly reactive and polar analytes.
• Automated canister lifecycle management combining cleaning, certification, and data logging.

Conclusion

The SilcoCan canister with RAVE valve unites high-performance deactivation, precision sealing, and validated cleaning protocols to secure sample integrity in VOC monitoring. Adherence to prescribed procedures and periodic reconditioning underpins long-term reliability and regulatory adherence.

Reference

Restek Corporation. A Guide to Whole Air Canister Sampling, lit. cat.# EVTG1073A.
United States Environmental Protection Agency. Compendium of Methods for the Determination of Air Pollutants (TO-12, TO-14A, TO-15).