Magnetic filter

The selection depends on the particle size and material properties. For large ferrous scraps, a range of 3,000 to 5,000 Gauss is sufficient. However, for fine paramagnetic particles or stainless steel abrasion in food and pharma lines, you must specify High-Gradient Magnetic Filters reaching 10,000 to 12,000+ Gauss. Always request a Gauss Meter Test Report from the supplier to verify that the surface magnetism meets your requirements.

For the outer casing, 304 or 316L Stainless Steel is mandatory to prevent corrosion, especially in liquid filtration. The internal magnets should ideally be Neodymium-Iron-Boron (NdFeB) for maximum strength. If the operating environment exceeds 80°C, you must specify high-temperature resistant grades (such as SH, UH, or EH) to prevent irreversible demagnetization.

Suppliers should adhere to FDA (Food and Drug Administration) or EC 1935/2004 standards for food-contact surfaces. Ensure the welding quality meets Sanitary Grade requirements (smooth, crevice-free welds) to prevent bacterial growth. For pressurized systems, verify that the filter housing complies with ASME Section VIII or the Pressure Equipment Directive (PED).

Manual cleaning filters have a lower initial cost but require operational downtime and labor. Self-cleaning (Automatic) systems are more expensive upfront but are essential for continuous production lines where stopping the flow is not feasible. Evaluate the Total Cost of Ownership (TCO) by factoring in labor costs and the frequency of iron contamination in your raw materials.

This is a common risk where suppliers use lower-grade magnets with thin sleeves to trick meters. Require a third-party inspection (such as SGS or Intertek) to perform a pull-test and Gauss mapping. Use Made-in-China.com’s Secured Trading services to ensure payment is only released after the quality inspection report is uploaded and verified.

Magnets are classified as 'Dangerous Goods' for air freight because they can interfere with aircraft navigation. You must ensure the supplier provides Magnetic Shielding Packaging (using iron sheets and foam) and obtains a Magnetic Inspection Report for Air Transport. For sea freight, ensure the packaging is vacuum-sealed with desiccant to prevent the NdFeB cores from oxidizing during long transit times.

Provide a detailed Technical Data Sheet (TDS) including flow rate, viscosity, and pressure. Negotiate for spare parts (like O-rings and gaskets) to be included in the initial bulk order. Professional suppliers on Made-in-China.com often provide CAD/BIM drawings for integration; ensure these are approved before production begins to avoid installation mismatches.

Always verify the supplier's Business License and Export Qualifications. Prioritize Audited Suppliers on Made-in-China.com who have undergone on-site factory inspections. Use Escrow-based payment terms and clearly define the 'Acceptance Criteria' in the Proforma Invoice (PI), specifically mentioning the minimum Gauss strength and material grade.