1 reply to this topic

[Perumal M]

Dear all,

 

I need clarification about the impact of negative temperature at the outlet of blow down valve.

 

I am doing BDV sizing calculation for HP KOD. 

 

Operating temperature - 50 degC (min. temperature 35 degC) (I use 50 degC for calculation )

Operating pressure - 120 barg 

 

When i do depressurisation study in hysys, I get -40 degC as minimum valve outlet temperature.

MOC - CS (Surely it will brittle.)

 

My question is,

 

Is there any way to increase the minimum temperature at the valve outlet ?

 

If we can not change the min. temperature, then guide me to select some other material.

 

Thanks and regards,

Perumal M. 

[fallah]

 

When i do depressurisation study in hysys, I get -40 degC as minimum valve outlet temperature.

MOC - CS (Surely it will brittle.)

 

My question is,

 

Is there any way to increase the minimum temperature at the valve outlet ?

 

If we can not change the min. temperature, then guide me to select some other material.

 

 

Hi Perumal,

 

In order to increase the valve outlet temperature, you can increase the blowdown time duration; if it's allowed, otherwise considering -40 degC as minimum valve outlet temperature you should use LTCS as MOC.