How can I analyze the effects of this orifice in a pressure regulator?

[MrBear]

Hi folks,

Firstly a little background, I work for a company that manufactures gas pressure regulators. Last year I was a machinist studying for my HNC in manufacturing engineering. Since passing work has given me the opportunity to work in the product engineering office as a product tester and work load within the office has increased lately due to expansion, I have been tasked with analysing a certain feature of the new product range.

I need to model the effects of the below orifice (in red), but I have no idea what I'm doing!

Are there any basic math techniques I can use to get a better understanding of what is happening at this feature?

Thank you for your time.

 

[insightful]

Is the inlet on the left (supply side) and the regulated side on the right? If so, it looks like this orifice puts regulated pressure under the diaphragm.

 

[MrBear]

Thanks for the reply Insightful, yes the inlet is to the right of the image. The orifice does indeed connect the regulated pressure to the upper chamber, what it also does is create a vacuum.

All my research is telling me that this is a Venturi, I'm not sure this is the case. Is there any way to prove/disprove this? What equations would I need?

Many thanks

 

[anorlunda]

Don't you have the engineers who designed it nearby?

 

[MrBear]

I'm afraid not, they're all in Holland. The company I work for purchased the product range, little information regarding the design came with it.

I have been told that this feature was designed through product testing ie. flow rigs.

 

[insightful]

Here's a good source:

http://www.documentation.emersonprocess.com/groups/public/documents/reference/d351798x012_05.pdf

Here's the page that, I think, applies to your question:

 

[MrBear]

That's magic, thank you so much. Funnily enough I was looking at it with a pitot in mind. I always thought that the process media has to enter directly into the tube rather than flow over it, hence my dismissal of the theory.