×
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

pneumatic pressure adder

pneumatic pressure adder

pneumatic pressure adder

(OP)
Does anyone manufacture a pneumatic pressure adder?

I have 2 pressures that I want to add together to provide a pressure signal to a Siemens SKP20 SSOV/regulator.

One signal is about 4"WC (natural gas) and the other varies from -0.5" to -2" WC (air).  I want to add the two together and provide a modulating signal of 2" to 3.5" back to the regulator.

Alternatively, I want to take the -.5" to -2" pressure and invert it to a positive pressure for my signal.
(i.e. -5"=> +.5" and -2" => +2")

3rd option is to use some sort of pressure regulator that has 2 inputs.  I have another available pressure source that is about 9-10"WC.  I could use that as my "power" and regulate it down to my desired control signal (2-3.5") using the aforementioned pressure signals.  Since this is a closed system however (no flow once the pressures are stabilized), the regulator would have to be a lock-up style.



Pesy

RE: pneumatic pressure adder

I'm sure it exists.  Google for pneumatic logic. I have some catalogs in the office, I'll try to remember to take a look on Friday or next week when I get back in.

However, I am worried about mixing natural gas and air in the same device, especially if the air is below atmospheric pressure.

If you have an internal leak the gas will get sucked into your vacuum system.  Potential BOOM.  Check the codes.

Alternately you could do independant pneumatic to electric transducers on each, process the resultant electric signals, then go back to electric to pneumatic.

RE: pneumatic pressure adder

Like MJ, I'm sure that pneu adders exist although I've never used them.  You could do this electronically.  Use a pressure sensor with analog or digital value output for each, send signal to a cheapo controller to do the math, then output a another signal to a third regulator.

TygerDawg

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