When selecting RJT Unions, you must prioritize 316L Stainless Steel for high corrosion resistance or 304 Stainless Steel for standard food-grade applications. Ensure the dimensions comply with BS 4825 Part 5 standards, which is the benchmark for RJT fittings. Pay close attention to the surface finish (Ra value); for sanitary use, an internal polish of Ra < 0.8μm is essential to prevent bacterial growth. Additionally, verify the seal material—EPDM, Nitrile, or Viton—based on the chemical compatibility and temperature requirements of your processing line.