The indication for using Heimlich valve is for drainage of:

Most patients with significant pneumothoraces (> 30%) require placement of a closed-chest catheter (8-20F) for acceptable reexpansion. This catheter then can be placed either to underwater suction drainage or to a Heimlich (one-way) valve. If a Heimlich valve maintains full expansion, the patient may be treated as an outpatient; however, if a Heimlich valve fails to reexpand the lung fully or if the patient's condition is not optimal, admission to hospital and underwater chest tube suction drainage is required. Ref: Theodore P.R., Jablons D. (2010). Chapter 18. Thoracic Wall, Pleura, Mediastinum, & Lung. In G.M. Dohey (Ed), CURRENT Diagnosis & Treatment: Surgery, 13e.