Steam condensate question

• Oct 26, 2007

• #2

BronYrAur

Mechanical

Nov 2, 2005

799

You're multiplying instead of dividing.

GPM Cond = (#/hr steam)/(8.35 #/gal)/(60min/hr)

So 1#/hr equals only 0.002 GPM

Since you have LP steam, flash loss in the condensate pump won't be enough to affect the GPM selection. If you know your steam load, you can calculate GPM.

 

Upvote 0 Downvote

• Oct 26, 2007

• #3

imok2

Mechanical

Oct 21, 2003

1,311

BronYrAur, Don't you have to find lbs of water first?

 

Upvote 0 Downvote

• Oct 26, 2007

• #4

TBP

Mechanical

Mar 28, 2001

1,187

500 lbs of steam per hour will give you 1 USGPM of condensate to pump or dump.

8.33 lbs of water per US gallon, times 60 minutes per hour = 499.8. Round it to 500 lbs/hr.


Check out the publication "Hook-Ups" by Spirax-Sarco. It's full of info like this. If you're threatening to buy some of their products (traps, control valves, condensate pumps, etc.) the local rep will likely give you a copy or two.

 

Upvote 0 Downvote

• Oct 26, 2007

• #5

imok2

Mechanical

Oct 21, 2003

1,311

TBP
Close enough however it will vary as the pressure goes up and down.

 

Upvote 0 Downvote

• Oct 27, 2007

• #6

TBP

Mechanical

Mar 28, 2001

1,187

imok2 - Nope, it's constant. 1 lb of water will evaporate into 1 lb of steam, which will condense back into 1 lb of water. The latent heat will vary, but that's another story.

 

Upvote 0 Downvote

• Oct 27, 2007

• #7

imok2

Mechanical

Oct 21, 2003

1,311

Yes I was referring to the latent heat of vaporization which would increase as the pressure would increase hereby increasing the condensation and visa versa.

 

Upvote 0 Downvote

• Oct 29, 2007

• #8

BronYrAur

Mechanical

Nov 2, 2005

799

One thing to remember is the warm-up load. I would suggest a 2:1 safety factor, although I have seen it as high as 2.5:1. It all depends on how fast you are warming up.

So for each 1 Lb/Hr of rated load, figure 2 or 2.5 lb/hr required for warm-up. You condensate pump will have to handle this additional load and must be sized accordingly. So your max pump load will then be 0.004 or 0.005 GMP for each lb/hr of running steam load.

 

Upvote 0 Downvote

• Oct 29, 2007

• #9

TBP

Mechanical

Mar 28, 2001

1,187

But isn't that why you have a condensate tank? Anyone involved with this kind of work really should check out "Hook-Ups". It is an awesome publication, and the local rep will usually give you one.

 

Upvote 0 Downvote