How to design a pressure regulator

[EngJW]

We have an industrial engine that we are equipping with electronic fuel injection. Our problem is the fuel pressure regulator. We currently have an aftermarket adjustable regulator that costs $150 and we cannot afford to add this much to the engine. It also has more features than we need. We are having difficulty obtaining the automotive type of regulator because our volumes are too low to purchase at oem prices.

Now for the part where I am asking for advice. I am contemplating designing a regulator specific to our engines. I understand how a regulator works by balancing diaphragm unit loading against spring force, but that is the extent of it. After looking through all the books I have and searching the internet, I am wondering if this requires a lot of specialized knowledge that is not published.

Also, can the diaphragms be obtained off the shelf, or do they have to be custom designed? I think I can handle the spring design. This project will only work if I can buy the pieces and design our own housings.

The regulator will be non-adjustable, and have an inlet, outlet, and return to the tank.

Thanks for any guidance, even if you just tell me to forget the whole thing.

 

[dbaird]

Have you checked with any of the manufacturers to see if they might be interested? Here is a couple links if you have not already visited them.

http://www.h2cars.biz/artman/publish/article_121.shtml

http://www.fisherregulators.com/technical/tableofcontents/

David Baird
mrbaird@hotmail.com
Sr Controls Engineer
EET degree.
Journeyman Electrician.

 

[Cockroach]

Do you know what I do? Go buy a particular model that is best suited to your application. Take it apart and make detailed prints of each component of the assembly. Put it back together again and throw it away.

Now take a decent look at your reversed engineered assembly. Introduce changes, small at first then advancing into major, significant modifications tailored to address your specific application. Make prints and check your assembly. Cut the prints for machining. QC the parts and assemble, test the unit.

Japan built an empire like this, reverse engineering to address miniturization, simplicity and therefore, cost reduction in large scale manufactured runs.

And do you know what? It works quite well.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada