Equipment setup question

I am currently using a converted sanke keg for a mash tun and another one for the boil kettle and a 10 gallon cooler for the lauter tun.  I filled my boil kettle with 7 gallons of water and brought it to a rolling boil and then set the timer for 60 minutes.  After 6o minutes I turned off the burner and measured the water level. It showed that I had 5 gallons left......which of course means I boiled away 2 gallons in 1 hour.  Does that sound normal?  Is it too harsh of a boil?
Anyway, the calculations showed that it was about a 9% boil-off rate. Does that sound right or am I doing something wrong?  I'm trying to get my equipment profile properly modified.
Will the 2.0 version have more keggle profiles available?

My kettle is a keg too.  I measure my boiloff rate every 15 minutes to acheive the rate I am looking for.  What is right is for you to determine for the way you want to make beer.  A hard boil like you had will change the beer color and flavor. I start with 7 gallons and end up with 6 which is close to 15%/hour.  I try to put 5.5 in the ferementer.  My recipes are adjusted to my process. 

So, you're not doing a vigorous boil.... it's more of a rolling boil?  I've been brewing for about 8 years and I've always done a vigorous boil, but, that causes me to lose 2 gallons. If I turned down my burner to make a light rolling boil, maybe that would get me down to losing just 1 gallon instead of 2.

Thanks!

DC Brewing said:

I filled my boil kettle with 7 gallons of water and brought it to a rolling boil and then set the timer for 60 minutes.  After 6o minutes I turned off the burner and measured the water level. It showed that I had 5 gallons left......which of course means I boiled away 2 gallons in 1 hour. 
Anyway, the calculations showed that it was about a 9% boil-off rate. Does that sound right or am I doing something wrong? 

Click to expand...

To the equipment set-up question, losing 2/7ths is more like 28.5%.  You may want to verify how you're measuring that, and whether the 7 and the 5 are truly accurate. 

As to normal, I have a keg/boiler too, and like JomeBrew, lose one gallon in an hour, so based on that sample of only two people, you're boiling more vigorously than us.  Hard to define "normal" but 28% seems a little higher than most.  You may be imparting some character to the brew by boiling that hard, but you also are getting higher gravity with less grain, so it's a trade-off. 

Thought I would add my 3 1/2 cents on the question of light rolling boil vs. vigorous boil.
A few points of simple physics:
1.  Nearly all of the liquid in a mash is water, with your grains and other adjuncts in solution.
2.  The boiling point of water is 212 F.
3.  Unless it is under pressure, water can not reach a higher temperature than 212F in the liquid state.
4.  Once you have bubbling over the entire surface, the temperature will not increase.
5.  Applying additional heat to reach a vigorous boil will not raise the temperature of the wort, but the added energy results substantially in more liquid water being converted to steam.
6.  Knowing these facts it seems obvious that the chemical effects on the wort should be the same except for the higher concentration due to evaporated water.

However, in the past I have burned the wort by having the heating source to high.  Though the liquid is limited to 212F, the pot can become hotter if it is insulated by any solids settling in the wort or if the additional energy can not be dissipated quickly enough.  This can cause the color change and off flavors mentioned by jomebrew.  In my opinion there can be no added benefit to a vigorous boil, and it is best to have a steady even boil over the full surface of the wort and be careful not to overheat.

That all makes sense. 
To TMC32, I used a 1 gallon measuring cup and poured 7 gallons in my converted keg.  I use a 4 foot section of copper tubing that is pre scored at 1 gallon increments to verify that I have 7 gallons in the keg.  At the end of the boil, I again used the copper tubing and it showed that I had 5 gallons left in the keg. 

I will do the test again with a lighter rolling boil and see what I'm getting.

DC Brewing said:

Anyway, the calculations showed that it was about a 9% boil-off rate.

..................To TMC32, I used a 1 gallon measuring cup and poured 7 gallons in my converted keg.  I use a 4 foot section of copper tubing that is pre scored at 1 gallon increments to verify that I have 7 gallons in the keg.  At the end of the boil, I again used the copper tubing and it showed that I had 5 gallons left in the keg.

Click to expand...

OK, if you're certain on the loss of two gallons, then the 9% evap rate indicates an error.  A loss of 2 from 7 would be 28.5%, and BSmith was saying 9%, so some other numbers are amiss and goofing up that calculation.  Post a recipe with that equipment profile and someone may spot the issue.