The plastic horizontal mechanical seal pumps are available with "Aqua-Seal," double water flushed mechanical seals with Dri-Stop pump protection. The "Aqua-Seal" arrangement is said to be ideal when pumping dirty abrasive solutions, electroless solutions, solutions that tend to crystalize or solutions at elevated temperature. The external water flush provides lubrication to the seal faces, which ensures reliable trouble-free operation in applications where other pump designs fail. The pump protector is designed to prevent downtime and costly pump repairs by de-energizing the pump motor when loss of cooling water occurs. Also, this arrangement allows the pump to continue to operate without damage even without pumped fluid, such as when a suction valve is accidentally turned off.