Specifying steam demand

[zamu2010]

Dear Folks,
I have a general question on how steam demand should be specified.
In some documents I read, the steam demand is mentioned in xxx kg/h.
Should the pressure of the steam be mentioned as well?
Is it a standard engineering practice?
Is not it somehow mis-leading the reader?
If yes, then how can i specify the steam pressure from this?
Demands in kg/h will vary by changing the pressure of steam.
Thanks in advace for your comment on the issue.

 

[ione]

It is necessary to specify both the mass flow rate (kg/h) and the pressure (barg). The equipment where steam is conveyed and used are rated for a specific amount of steam and a specific pressure. The thermal output mostly depends on latent heat of steam, as steams turn to condensate in the heat transfer process. Latent heat changes, and more specifically decreases, with steam pressure (this should answer your question about the mass flow rate demand variation with pressure). So it would be opportune to use steam at the lowest pressure allowable.
Moreover steam temperature is directly related to its pressure, and it is necessary to account for that when the process requires that specific temperatures are reached.