Selecting mechanical seal cooling/flash plan (Seawater Service)

[MechatroPro]

whats the best way for flushing and cooling the mechanical seal for a seawater service?
Attached is the drawing of the pump, its a polymer lined pump for seawater+hcl(2000mg/l) service.
Head: 50m, 60m3/h

 

[MechatroPro]

Does the mechanical Seal for this type of service require an API Plan and constant cooling and lubrication with sealing liquid? or washing the mechanical seal surfaces before running the pump after each shutdown, suffices?

 

[RHurst]

There are a lot of factors that dictate what API piping plans are required for reliable seal operation.

To understand if we need a flush to cool the seal we would need to understand what the seal generated heat would be as well as some other fluid properties to determine if lubricity is going to be an issue (always a concern with water). Things like shaft speed, seal size, process temperature, SG, viscosity and seal chamber pressure are the basic parameters for this calculation. Your selected seal face materials are also an important factor.

One important thing to understand from the cross section of your pump and the seal arrangement indicated in the attached is that all that you are capable of providing for the seal is an atmospheric flush/quench or API Plan 62. While this can provide some cooling it just bares mentioning that there are limitations to what you are going to be able to do with this arrangement.