What are the precautions when purchasing SF6 gas handling equipment?

When purchasing SF6 gas handling equipment (including recovery machines, inflators, purifiers, etc.), the core precautions focus on matching actual needs, complying with standards, ensuring safety, and controlling long-term costs. Below are the key points categorized by core dimensions to avoid buying inappropriate or low-quality equipment.

1. Clarify Demand Matching: Avoid "Over-Matching" or "Under-Matching"

First, define your specific usage scenarios and technical requirements to ensure the equipment’s performance aligns with actual needs.

Confirm application scenarios:

• For substation GIS maintenance: Prioritize high-recovery-rate equipment (≥95%, meeting DL/T 1555-2016) with large processing capacity (≥50 kg/h for 220 kV+ GIS).

• For laboratory small-volume SF6 handling: Choose portable equipment (weight ≤20 kg) with high purification accuracy (purity ≥99.99%, moisture ≤30 μL/L).

• For on-site emergency leak recovery: Select mobile equipment with fast startup (≤5 minutes) and battery-powered options (to avoid relying on on-site power).

Lock key technical parameters:

• Recovery machines: Focus on vacuum degree (≤1 mbar, to ensure thorough gas extraction), cooling efficiency (can liquefy SF6 at 0–5°C), and oil-free design (prevents oil contamination of SF6).

• Purifiers: Confirm filtration accuracy (solid particles ≤0.1 μm) and adsorbent capacity (e.g., molecular sieve lifespan ≥1,000 hours of continuous use).

• Inflators: Check pressure control precision (error ≤±0.01 MPa) and moisture removal function (built-in drying tower to avoid introducing moisture during inflation).

2. Comply with International/National Standards: Ensure Legality and Reliability

SF6 handling equipment is subject to strict environmental and safety standards; non-compliant products may cause emissions or safety hazards.

Mandatory standard compliance:

• International standards: Meet IEC 60480 (SF6 reuse specifications) and IEC 62271-4 (GIS gas handling procedures).

• National standards: For China, comply with GB/T 12022-2015 (SF6 purity requirements) and GB/T 44653-2024 (on-site SF6 recycling guidelines); for the EU, align with the F-Gas Regulation (517/2014) (emission control requirements).

Certification checks:

• Ask the manufacturer for type test reports (e.g., from authoritative institutions like China Electric Power Research Institute or EU CE certification).

• Confirm that key components (e.g., compressors, vacuum pumps) have independent certifications (e.g., ISO 9001 quality certification) to avoid using unqualified accessories.

3. Prioritize Safety Design: Prevent Leaks and Accidents

SF6 is a greenhouse gas, and its decomposition products are toxic. The equipment’s safety design directly affects operator safety and environmental protection.

Leak-proof structure:

• Check if the equipment’s gas path uses double-seal connections (e.g., O-rings + metal gaskets) and if the hose interfaces are compatible with SF6 (e.g., fluorine rubber materials, no aging or cracking).

• For storage tanks/cylinders, confirm they meet high-pressure vessel standards (e.g., China’s GB 5099) and have passed hydrostatic testing (valid for 3 years).

Safety protection functions:

• The equipment must have overpressure protection (automatic shutdown when pressure exceeds 12 MPa) and overtemperature protection (motor shutdown when temperature >80°C).

• For purifiers/recovery machines, ensure they are equipped with acid gas adsorbents (e.g., CaO) to neutralize toxic decomposition products (HF, SO₂) and avoid operator exposure.

Operator safety support:

• Portable equipment should have a low-noise design (≤75 dB) to avoid noise pollution during on-site operations.

• Check if the manufacturer provides matching safety accessories (e.g., pressure gauges with calibration certificates, leak detection sprays) to avoid additional purchases.

4. Evaluate Quality and After-Sales: Control Long-Term Maintenance Costs

Low-quality equipment may have frequent failures, increasing maintenance costs. Focus on component quality and after-sales service capabilities.

Core component quality:

• Compressors: Prioritize oil-free scroll compressors (e.g., brands like Bitzer) with a service life ≥8,000 hours (avoid piston compressors, which have high oil content and short lifespans).

• Vacuum pumps: Choose rotary vane vacuum pumps with a ultimate vacuum ≤0.1 mbar (e.g., Leybold, Edwards) to ensure thorough gas extraction.

• Filters/adsorbents: Confirm the manufacturer provides easy-to-replace consumables and clearly marks their service life (e.g., filter replacement every 500 hours).

After-sales service guarantee:

• Require a warranty period of at least 1 year (core components like compressors should have a 2-year warranty).

• Confirm the manufacturer has local after-sales service points (or provides on-site maintenance within 48 hours for faults) to avoid long downtime due to remote repairs.

• Ask for operator training services (free on-site training or online courses) to ensure your team can use the equipment correctly.

5. Compare Cost-Effectiveness: Not Just "Cheap Purchase Price"

The total cost of ownership (TCO) includes the purchase price, maintenance costs, and energy consumption—avoid focusing only on the initial price.

Calculate long-term costs:

• Energy consumption: Choose energy-efficient models (e.g., recovery machines with a power ≤3 kW for 50 kg/h capacity) to reduce electricity costs.

• Consumable costs: Ask for the unit price and replacement cycle of filters, adsorbents, and hoses (e.g., a filter that costs $200 and lasts 500 hours is more cost-effective than a $100 filter that lasts 100 hours).

Avoid "three-no" products:

• Do not buy equipment without a clear manufacturer, production date, or test report—these products often have no after-sales support and may not meet environmental standards, leading to fines during inspections.