Toilet valve for low pressure

We have a cabin where the water pressure is from a storage tank not much above the second floor, which means low water pressure. Toilet valves have always been a problem--either they don't work properly or filling is very slow (10 to 15 minutes). The toilet is an older (higher volume) model.

Is there any valve that's made to work with low water pressure? We need a valve that opens farther and lets in a greater volume of water. We do have a booster pump that can be turned on for short periods, but it seems silly to have to tell everyone to turn it on every time the toilet is flushed.

Thanks for any help--
Dan

The problem is not the valve. The problem is your supply line is too small for the low pressure to push enough volume of water. Please understand that pressure is not the same a volume, but you do have to have some pressure to push the water. The pressure will be the same no matter what size the pipe, but if you can increase the pressure with a pump, you will get more volume. Likewise, if you increased the size of the supply line, you'd get more volume.

perssure

Are you trying to fill by gravity?