×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

vacuum pump sizing

vacuum pump sizing

vacuum pump sizing

(OP)
Ill be pulling a vacuum on a 240 ton self contained chiller, it has two circuts. My rule of thumb in the past has been 1 cfm per 7 tons of cooling. Looking at the physical size of the expansion valves this could be a 1/3-2/3 set up.IF my rule of thumb is correct, two 10 cfm pumps should be big enough for one circut, but if I use two pumps of equal size will they pull the vacuum oil out of each other and into my refrigeration system.

RE: vacuum pump sizing

1 10 CFM pump will be plenty. Id be more concerned with the size hoses or copper your going to use between the vp and chiller. If your using 1/4" hoses youll never get the full benefit of the 10 cfm, the hoses will restrict your pumps ability to pull out of the chiller. Use a 1/2 hose if you can. Ive pulled down many a centrifugal with a 10 CFM pump with no problems using 1/2" hose/copper.  

RE: vacuum pump sizing

(OP)
thanks I also use 1/2 inch braided hoses.I just wasnt sure of my rule of thumb calculations ,this is one of the biggest machines Ive worked on.We have bigger and with the prices of some of the bigger contractors my company is keeping a little more work in house.Thanks again for the input Ill keep my eyes and ears open in this forum.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources