What brand/model amp do you have?
I had a similar situation that went on for several months. It was totally frustrating and made me consider giving up tubes, but an electrician and I discovered the root of the problem was loose (old) sockets. If an amp is on and a power tube loses contact, it wrecks havoc on resistors, caps, neighboring tubes, etc. Blowing tubes isn't normal. If you like the way your amp sounds, have a technician look at it. Find someone in your area that knows tubes. It could be something as simple as resistors and sockets.
Best of luck!
I had a similar situation that went on for several months. It was totally frustrating and made me consider giving up tubes, but an electrician and I discovered the root of the problem was loose (old) sockets. If an amp is on and a power tube loses contact, it wrecks havoc on resistors, caps, neighboring tubes, etc. Blowing tubes isn't normal. If you like the way your amp sounds, have a technician look at it. Find someone in your area that knows tubes. It could be something as simple as resistors and sockets.
Best of luck!