... , brass gear, PPO parts, large output torque, long product life. 2, Electrical limit and machinery limit design, accurate position, avoid gear ... 1, IC card meters, heat energy meters, air-warm valve. 2, HVAC and fire work. 3, Water equipment, uto-controlwatersystem, industrial ... water heaters, washing machins, water heaters, industrial eletric warm valve1/2" brass full port for heating system