How to reverse engineer gaskets?

[genti1]

Hi everybody,
I'm looking for some suggestions on how to reverse engineer gaskets. I did some researches on internet but I still believe that the best suggestion is going to come from engineers that have been through reverse engineering gaskets. In my case, I do have a gasket (sample) and I'm trying to find what kind of material should I use, how thick etc. I'm actually willing to go and take some courses but at the moment I have to solve this one that I got on my hands (there is no time to wait for this one). I'm inexperienced on this field and I just got this job so any kind of help would be very appreciated.
Thanks again,
Genti

 

[BusaJames]

I would try contacting a gasket manufacturer. If they think you may be a future customer they might give you an insight on what you are looking for. Or you could describe the application some and ask for help here. Most likely there will be someone with the experience to point you in a direction.

 

[drawoh]

genti1,

Do you understand the problem the original designer was trying to solve?

For example, the designer may have selected the gasket material because that is what the company always makes gaskets out of and it is known to work. It may have been selected because it is the one and only material that works around the chemicals they are using. You need to know what the chemicals are, what temperature they are at, how the gasket is to be compressed, if and how the system will be taken apart. There could be safety issues.

Your gasket is part of a system that has to function somehow. Treating a system as a collection of unrelated parts is a reliable way to design junk.

Is there any reason you cannot get design assistance from the original fabricator/designer?

JHG

 

[genti1]

Drawoh,
The gasket that I'm trying to reverse engineering is a sample that was sent to us from a company that buys these gaskets from another company but they aren't happy with the price and delivery time from the current vendor ( we are assuming that isn't a design issue). However, I've already asked for more info on what kind of media, what temp. and what pressure does this application sees. Meanwhile, I'm trying to be done with calculating what is the bolt load that the gasket (sample) that I have it was design to see by reverse engineering it ( by using the number of bolts, size of bolts, contact surface of the gasket with the flange, things that I can get from the sample).
So, to answer your question if "Is there any reason you cannot get design assistance from the original fabricator/designer", I would say that we don't even know who they are at all. All we got here is the sample and hopefully we'll get all those parameters that I mention above, pressure, temp. and media from the customer.
Thank you,
Genti

 

[Kriegen]

genti1,
This case is something that many companies throughout the world do everyday. Usually it is so they can send the plans to China and make it so much cheaper.
Anyway, make sure that you know what the mating surfaces are like exactly. Omitting this step can become very costly. Next there are plenty of programs out there that can tell you exactly what pressure this material is supposed to stand up to. Drawoh is correct in saying that the designer may have just used it because thats all the company has ever used. There are plenty of stress strain equations to use to decide on other materials than what you have. As for finding out what you have, your own guess, or the guess of someone more experienced can almost always lead you in the right direction. There are also plenty of labs that will verify your substance for a small fee. Say $100 per article. This would be nothing for your company I am sure. Also once you have accomplished all of this to try and copy the original designers product, step back and reevaluate how to make it better. Sometimes the designer was just in a hurry to get the product on the line and could have made it so much better or cheaper.
Hard Work and dedication are the key to copying.

 

[drawoh]

genti1,

If you know the media, the temperature and the mechanical interface, why not just design the thing, and forget about the sample? One of many possibilities here is that your sample does not work very well. Another possibility is that the other vendor has already had all your clever ideas and has determined that they do not work.

I would not want to go anywhere near this thing unless I understood what it had to do. There is no other thing on which you can responsibly base design decisions.

What are the consequences of failure? The gasket does not have to release superheated steam into a room full of people to be dangerous. All you have to do is strand someone's seventeen year old daughter on a lonely highway at ten in the evening.

JHG