API Plan 22

• Similar to Plan 21 but with the addition of a strainer to remove occasional solid particles.
• Acts as a flushing as well as a self-venting plan for horizontal pumps.
• Uses a flow control orifice to restrict the flow of flush fluid going to the mechanical seal.
• Improves the product temperature margin thus avoiding vapor formation.

• Slightly contaminated (fluids with suspended solids), non-polymerizing fluids with high temperatures.

• Strainer to be installed before the orifice.
• Strainers often have a tendency to choke and thus lead to starvation and, eventually, failure of the mechanical seal.
• Minimum size of the orifice should be 3 mm (1/8").
• Cooler duty is high, leading to fouling and plugging on the water side.
• This plan does not function reliably enough to achieve a three-year operating life and is therefore not generally recommended. Plan 32 or a dual pressurized seal is a recommended option for such duties.

• High temperature with some suspended solids.
• Close to vaporization point.

• Process side
• Flushing and cooling

1CW-FL, 1CW-FX, 2CW-CW, 2CW-CS, 3CW-FB
 

3CW-BB*, 3CW-FF*, 3NC-FB*, 3NC-BB*, 3NC-FF*

* Remark: The configurations listed for each individual piping plan are to be understood as recommendations including possible utilizations which may also be applied.