How is backsuction of HCl prevented? Pls help me i dont know what else to write its asking for more than 50 characters

HCl is soluble in water so it is absorbed in water more quickly . so in the preparation of HCl the pressure in the delivery tube and flask is reduced and atmospheric pressure from outside forces the water back upto the delivery tube . this effect is back suction

 Avoid suctioning too frequently as this could lead to more  buildup.