FU-824F/FB/S/SB type tube for direct thermal carbonization thorium-tungsten cathode metal ceramic triode,the anode cooling method for water-cooled (S/SB) and forced air (F/FB),the maximum anode  dissipation power is 5KW,the maximum operating frequency is 75MHz,the output power up to 10KW. the pipes are mainly used in industrial high frequency heating equipment.