ANSI PUMP WITH API PLAN 11

SiC/SiC/Viton/Hastelloy C with API plan 11

The PLAN 11 flush plan is a mechanical seal flushing arrangement specifically designed for high-pressure, high-temperature, and solids-laden fluid applications. By optimizing the flush fluid flow path and controlling the flow rate, it ensures the mechanical seal maintains peak performance and an extended service life while minimizing the risk of leakage.

Applications:High-pressure pumps (e.g., high-pressure plunger pumps), high-temperature fluid handling equipment (e.g., hot oil pumps), pumps handling media containing solid particles (e.g., slurry pumps), and scenarios requiring superior sealing performance.

Working Principle: An external high-pressure flush fluid source introduces clean, cool liquid into the mechanical seal chamber to effectively flush and cool the seal faces. The flush fluid enters from the outer side of the seal faces; after passing across the faces, a portion of the fluid is forced back toward the inlet side by the process medium pressure—creating a circulation loop—while the remainder flows out along with the process medium.

Flush Fluid Selection and Requirements: Fluids selected are typically compatible with the process medium, possess moderate viscosity, and are non-corrosive or minimally corrosive (e.g., water, aqueous glycerin solutions, light oils). The flush fluid temperature must remain below the maximum allowable operating temperature of the seal materials; the use of a filter to pretreat the flush fluid and remove impurities and particulates is recommended. The flush fluid flow rate should be appropriately adjusted based on the equipment's specific operating conditions and sealing requirements.