There are many different pipe sizes, walls, and manufacturers. A chart that included all the sizes would be quit large. Also, each machine has a different piston area used in the calculation -- so we're talking a lot of large charts. However, here are some valuable resources that will help:
http://www.mcelroymfg.com/fusion/soluti ... ebcalc.htm
This is an on-line calculator
http://www.mcelroymfg.com/fusion/solution/pressure.htm
This page provides the basic theory of the calculation
http://www.mcelroymfg.com/fusion/flash/fusecalc.htm
This last link will show you how to use and permit you to register for a free slide rule (English and metric) to keep with your McElroy fusion machine.
Keep in mind that in addition to the pipe size and wall thickness, you will need to know what model machine you will be using. (make note of the color of the hydraulic cylinders - green, orange, or yellow) You will also need to know the pipe manufacturer's recommended Interfacial Pressure or IFP. You can get this from the pipe manufacturer. (Their name should be marked on the pipe)
There is also a generic procedure available from PPI at:
http://www.plasticpipe.org/pubs/downloa ... /tr-33.pdf