2017-6-28 Purification Technology Edition Daily Question
Thread Content
1. The purpose of installing a minimum return pipeline in centrifugal pumps is to prevent cavitation. （） 2. When there is no instrument air supply, the control valve opens ； When there is a gauge air supply, the control valve closes; it is thus a air-operated valve. ( ) Right or Wrong Note: Answers to this question must be submitted within 3 days! ! !
Error---------Error