There are many chest drainage systems but the most traditional is underwater seal chest drainage system. This system is a device that is attached to long hollow plastic tube that is inserted in the the chest wall between the ribs and pleural space. The purpose of this system is to allow blood,fluids,pus or air to be drained from the intrathoracic space. In doing so this allows the lung to re-inflate by restoring negative pressure. underwater seal chest Drainage system is commonly used in the treatment of pneumothorax, pleural effusion, and empyema. An underwater seal drainage system typically has four components the drainage chamber, the water seal chamber ,the suction control chamber and the positive pressure valve. The first chamber is the drainage chamber, this chamber is where the drainage from the chest is collected. The second chamber is the the water seal chamber, this chamber allows air to leave the chest and not renter.Tidaling may be seen which is fluctuation of sterile water in the chamber secondary to inhalation and exhalation. Gently bubbling may be seen in this chamber if the patient coughs or exhales. Continually bubbling in this chamber is indicative of a system and all tubing from Client to device should be checked. The third chamber is the suction control chamber the height of the sterile water in this chamber will determine the amount of negative pressure that is applied. The higher the sterile water volume, more suction will be produced. To much suction can cause vigorous bubbling the can cause evaporation of the water in this chamber. Lastly is the positive pressure valve, this valve automatically opens when a increase of positive pressure is sense in the system. You know the client drainage system is functioning properly when drainage is consistent in the drainage chamber, tidaling is noted in the water seal chamber and gentle bubbling noted the the suction chamber. This drainage system commonly stays inplace until the air or fluid is expeled and the lung re-inflates.