I'm about to buy my own set of doubles (vs. relying on instructor) and have been debating the Faber LP85's vs Faber HP100's. I'm in FL, so getting "cave fills" or relatively high pressure fills isn't a problem here even with LP's, but for my own peace of mind, I want to make sure I'm not making mistakes.
The Faber LP85 is a 13L tank and is actually 81.1cf @ 2640psi. The HP100 is a 12.9L tank and real capacity is 101.3cf @ 3442psi. Their volume is basically the same and they hold the same amount of gas at a given pressure. So all else being equal the HP100 should be the preferred tank as it's rated for the higher pressure and even if you fill it above stated pressure, it's more capable of dealing with said pressure. Here are my calculations:
They hold essentially the same amount of gas, so then the only other variable is weight/buoyancy characteristics. I'm not concerned about the buoyancy when full, partly because more gas weights more, so that's not a valid comparison. However when empty there's about a 3lb difference in buoyancy in water and weight on land. Two tanks and that's 6 lbs of additional weight. I know up north additional weight is preferred as it takes weight off your belt, but I'm not sure how I feel about that in FL.
So I guess the question are:
1. Is my logic sound? Anything that I'm overlooking?
2. Which tanks would you choose if weight didn't matter?
3. Would you still choose the same tanks with the buoyancy considerations? I have no need for extra weight.
Keep in mind, these will be back-mounted, not side-mounted. My stage/deco bottles will be aluminum. Lastly, although I'm not typically concerned about getting the LP85's overfilled to 3k+, I also don't want to be in a situation where I have to beg for it or risk not getting a full fill. I've been getting bout 3-3.2k on the LP95's, while the rented HP100's were filled to 3500+ without problems. Having said that, one of the shops told me they fill LP's to rated pressure.
Thanks in advance!
P.S. I don't care about the marginal difference in price between the two
P.S.S Looking to compensate for the added weight with a CF backplate
P.S.S.S. I believe the Faber are my only HDG (Hot Dip Galvanized) options available as new right now, if there are options I'd love to hear about them
The Faber LP85 is a 13L tank and is actually 81.1cf @ 2640psi. The HP100 is a 12.9L tank and real capacity is 101.3cf @ 3442psi. Their volume is basically the same and they hold the same amount of gas at a given pressure. So all else being equal the HP100 should be the preferred tank as it's rated for the higher pressure and even if you fill it above stated pressure, it's more capable of dealing with said pressure. Here are my calculations:
They hold essentially the same amount of gas, so then the only other variable is weight/buoyancy characteristics. I'm not concerned about the buoyancy when full, partly because more gas weights more, so that's not a valid comparison. However when empty there's about a 3lb difference in buoyancy in water and weight on land. Two tanks and that's 6 lbs of additional weight. I know up north additional weight is preferred as it takes weight off your belt, but I'm not sure how I feel about that in FL.
So I guess the question are:
1. Is my logic sound? Anything that I'm overlooking?
2. Which tanks would you choose if weight didn't matter?
3. Would you still choose the same tanks with the buoyancy considerations? I have no need for extra weight.
Keep in mind, these will be back-mounted, not side-mounted. My stage/deco bottles will be aluminum. Lastly, although I'm not typically concerned about getting the LP85's overfilled to 3k+, I also don't want to be in a situation where I have to beg for it or risk not getting a full fill. I've been getting bout 3-3.2k on the LP95's, while the rented HP100's were filled to 3500+ without problems. Having said that, one of the shops told me they fill LP's to rated pressure.
Thanks in advance!
P.S. I don't care about the marginal difference in price between the two
P.S.S Looking to compensate for the added weight with a CF backplate
P.S.S.S. I believe the Faber are my only HDG (Hot Dip Galvanized) options available as new right now, if there are options I'd love to hear about them