Design Velocity for Drain Steam Lines

[Boghi1990]

Boghi1990 (Mechanical)
9 Dec 11 1:30
Hi davefitz,

I have several drain lines piped to a flash vessel. The drains are collected into 4 manifolds. Superheated steam flows through these drains. Sonic velocity(choking) occurs at the end of the drains. I am trying now to size the manifolds. I was looking for recommended velocities for superheated steam lines and I have come across with your past thread regarding the Design Velocity for Steam Lines.

Could you have any suggestion on what velocity should I use to size the drain manifolds?

In your post you have mentioned that: "For simple drains dumping to flash tanks or condensers, an inlet velocity of 30% sound speed ( mach=0.3) is typical..."

Could you please tell me where is the inlet velocity ? From where did you get that inlet velocity of 30% sound speed ?

I also have to size the drain tank. What velocity I could use? The drain tank is connected to a surface condenser (Pressure 0.736 psia and Temperature 91.7 F)

Any suggestion is very much appreciated.

One Point