In static liquid pressure is caused dy gravitation or weight forces?And can weight is also be a predominant factor that cause pressure during liquid flow?

This seems to be an engineering question to me. But, some thoughts: since weight is the result of gravitation, your question seems redundant. Also, one can have pressure in the absence of gravity - space or in free fall. In real life flow usually is the result of pumps rather than just gravity. But if you fill a tank with water and punch a hole in it, the resulting flow is due to gravity.