Is the red glow normal for 845 tubes?

Thank you Brf and Dopogue for your input! According to the manufacturer the dissipation rating for the Sino 845 is 70W. The amp is a self-bias so there is no need for adjustment. The tubes in question are Sino 845 (not B, C or W). I got the amp second hand with this type of tubes and I do not know if these tubes are the originals. I wrote to Bel canto about the dissipation requirement for the SETi 40 tubes but so far I have not received an answer. I should clarify that the red glow is present in 95% de the graphite plate, and after shutdown it last about 2 min. If I continue using the amp this way would I damage something? So far I have used the amp about 150 hr and I like it very much, I just noticed the red glow last night!! because I lisen music during the day. Thanks again for your help!

Thanks again Brf. I just run into an article in VTV (vacuum tube valley) where it says "graphite es heat-resistant (in fact, it can operate with a dull red glow for a long time without failing)" in power tubes like the 811 o 845. However a new set of 845 tubes is coming my way.

I just got an answer from Mathew Cramer from Bel canto. He says that "the red glow is normal for this type of design" (SETi 40). So that settles everything down. Thank all for your help. Tiofelon.

Good point Brf! He did not said anything regarding the low dissipation. I will ask him if the SETi 40 is biased for a standard 845 tube (100 W dissipation).

I got another answer from Bel canto stating that the dull red glow from the graphite plate is normal and that the amp can drive just fine the 845 low dissipation tubes. Bel canto did not said anything regarding the amp bieas for a hight dissipation tube or for a low one. Thanks again Brf.

Got an another answer from Matr Cramer at Bel canto. He says that "a dull red glow is normal for a 845 tube, but he recommends using a 845 tube with a 100W dissipation or they can fix the amp so that it can lower the dissipation rate as it prolongs the life of the tubes." So according to Bel canto and Brf the amp runs fine. It this the life of the tubes that is in danger of premature failure. Thanks Brf.