When sourcing butterfly lever valves, you must prioritize material compatibility and pressure ratings. Ensure the body material (e.g., Ductile Iron, Stainless Steel SS304/SS316, or PVC) matches the corrosive nature of the fluid. The seat material (EPDM, Viton, or PTFE) is critical for leak-proof sealing; for example, EPDM is ideal for water, while PTFE is required for aggressive chemicals. Additionally, verify the nominal pressure (PN10, PN16, or Class 150) and the connection type (Wafer, Lug, or Flanged) to ensure seamless integration with existing piping systems.