When purchasing mechanical seals, how to select an API 682 flush plan based on fluid and duty?
• Conclusion: use Plan 11 for clean ambient fluids; switch to Plan 32 or 53 for solids or high temperature.
• For abrasive solids, choose Plan 32 external flush with flush pressure 0.1–0.15 MPa above seal chamber.
• For hot oil or volatile fluids, choose Plan 53A/53B with barrier pressure 0.15–0.3 MPa above seal chamber.
• Dual seals must use Plan 53 or 54; single seals are not acceptable for toxic media.
• Require the supplier to provide a flush plan schematic with flow, pressure and temperature noted.
• For abrasive solids, choose Plan 32 external flush with flush pressure 0.1–0.15 MPa above seal chamber.
• For hot oil or volatile fluids, choose Plan 53A/53B with barrier pressure 0.15–0.3 MPa above seal chamber.
• Dual seals must use Plan 53 or 54; single seals are not acceptable for toxic media.
• Require the supplier to provide a flush plan schematic with flow, pressure and temperature noted.