Page Writes too high but normal values on PLE and BCHR? Today I was just taking a look on my performance counters and found this...

Average Batch Request per second was 0,6
Average Page Reads per second was 12,5
Average Page Writes per second was ~15000
Average Checkpoint Pages per second was ~15000
Average Page Splits per second was 325


Buffer Cache hit ratio at 99%

Page Life Expectancy at 37256

After searching a bit I found that more than 90 Page Reads and Writes per second could indicate memory pressure but how Page Writes could be an indicator of memory pressure if for example I'm loading data in tables constantly? 

Thanks!
Page write is just an indicator of logical writes as well as physical writes.
Logical write is an operation that happens when the page is being written in the buffer(dirty buffer) and physical write is an operation that happens when the same dirty buffer is converted to clean buffer and is being written on the physical disk.

Definitely, this is not a single metric to judge memory pressure. You need to combine different metrics for coming to a conclusion.

But in your case, it doesn't seem to be a problem as your page life expectancy is quite high which indicates a page will remain in the buffer for around 37k secs. 
So you don't need to worry about memory pressure I think.