845 output tube for my Caztech Amp

One of the 845 tubes was broken and needs to be replace.I would like to replace both amps with a matched pair. The tube that is broken was made in China but no name on it. The plates are graphite, the output rating for each amp is 22 watts. I have read that the Psvane 845 has 70 watts plate dissipation and I am not sure if that is ok. I know that the old 845's made in the usa had 100 watts dissipation. Thanks for your help. George