Mechanical Seal Fcae(CARBON) WORN OUT phenomenon in High Temperature water pump 1

[Falconheavy2]

Hi, we are running HIGH TEMPERATURE & HIGH PRESSURE Water pump ( about 45 kg/cm^2 / 110 'C)


First of all, we are using Seal plan 32/61 (actually we dont using 61 right now)
32 plan with 108 'C seal coolant water get in to M/SEAL (Vendor recommend 80'C, but there is a little problem in cooling unit, so right now , inlet water to cool M/SEAL temperature is over 108'C)

The problem is...
the seal face, actually the part of Carbon WORN OUT Continuously.
I know that we have to more cooling ability for 80'C , that's why i have to know the reason of below ( to persuade my boss :> )

HERE'S THE THINGS!!
WHAT HAPPENS ON MY SEAL
i asked for the vendor of M/SEAL , he was likes, the high temp' of water (over 100'c) become a steam, and its evaporation or condensation can be damaged to seal

is it right ?
something gonna happen likes cavitation ?

please describe me, what makes my seal fail....

 

[JJPellin]

You are correct. Your seal is failing as a result of the water between the seal faces flashing to steam. Steam is not a good enough lubricant to prevent hard contact between seal faces. The seal is running dry. You need to reduce the temperature. For this service, we would normally use a Plan 23 with circulation from the seal to a cooler in a somewhat closed loop set-up. This can drop the water temperature around the seal much lower. For your pump, using a water cooler, you should be able to drop the temperature at the seal down to 40 °C or lower.

Johnny Pellin

 

[gerhardl]

Fully agree!