Larger parallel gate valves (except those with floating seats) have seat loads so high at high fluid pressures that friction between the seats can make it difficult for the wedge to lift from the closed position. Such valves typically integrated with a valve bypass line and bypass valve to release the seat load before opening. There are no quick rules on when to use the integral bypass valve, CARBONVALVE advice can be sought. Some gate valve standards contain recommendations for minimum bypass sizes. In the case of condensation of gases and vapors in the downstream cooling system, the pressurization of the downstream system can be significantly delayed. In this case, the size of the bypass line should be larger than the recommended minimum size.