Are you saying that SCH40 pipe will work for a mast?Hi BMJ11, on a quick read it looks like you might be thinking of using a 2 inch PVC pipe as a mast.
If that is the case don't! A 2 inch steel mast would be way stiffer and stable - will not move around with humidly and temperature changes.
You may be able to find a lighter gauge galvanized in the fence department at one of the big box stores.
SCH 40 pipe is another option but way over kill for anything less then a 90CM FTA dish with motor.