Please let me know the required documents for tourist visa & time period to issue visa.

I am an airline staff in Sri Lanka. On my way back from Seoul with my family I have to wait few hours in Hong Kong for connecting Cathay Pacific flight to Colombo. So as a airline staff we are getting subload ticket & have a chance of offloading. In that case my waiting time may extent. So I need a tourist visa To Hong Kong. Please let me know the required documents for tourist visa & time period to issue visa.