Question about vac bell glans irritation.

So whenever I put my glans in a vacuum bell with a silicon sleeve and pulling for even 5 mins with super low tension, my glans become very irritated and sticky.
After some days it recovers back to normal.

If I ll put a silicon protector cap on my glans before entering the bell… Will this glans irritation stop happening?

Are you taping your glans prior to entering the chamber? Or just going in bare?

Bare.

When you say taping…. Do you mean the pee hole?

Not necessarily.
Going bare can cause irritation for some.
Couple things to try:
Use micropore tape to cover the glans (always put a little piece of toilet paper over the meatus - quite uncomfortable to peel tape from the meatus and TP will protect it underneath the tape).
Some find micropore tape too adhesive/irritating, so you can place your strips of tape on another area of skin (thigh) and peel it off to reduce the tack and then place on your glans.
I personally put tape over the glans, then a glans cap to cover below glans and tape the cap to my skin below circ scar. I find taping the area below the corona to be irritating, so I make sure the cap covers down to the shaft skin, which is more resilient.

OK and why Tape when you can use a silicon cup?

Is there any difference in result?

I have personally found the glans cap to help moreso with “packing” the bell cup. Glans caps tend to be very pliable and the suction from the bell can pull it away from the glans with higher levels of tension. Taping plus glans cap is a hedge against blisters and irritation. I’ve never had a blister with taping. I did have some mild irritation on one side of my corona at one point, but the addition of the gland cap resolved that.
The bulk of PE is trial and error - you’ll see everybody does something a little different, but the basic principles are the same (mainly going low and slow consistently for months to years). It took me a good 10 months or so to settle into a routine that I found to be comfortable and manageable long term.
Good luck.

The silicone cup is stretchy and will expand under vacuum. It still keeps pressure on the glans, so it helps prevent or minimize blisters.

The tape is not stretchy; done properly, it will prevent blisters entirely. Well, mostly.

The cap is easy to put on, and is re-useable. It’s quick to remove and replace when you have to pee.

The tape is harder to put on properly, hard to take off, is not re-useable, may not stay put if you sweat a lot, and is a hassle when you have to pee.

If you’re using a gasketed device like a Size Doctor instead of a sleeve and bell, the silicone gap seals easily to the gasket. Tape may not seal as well.

[allow a lot of hand-waving for specific brands of tape, application techniques, and the just plain cussedness of the universe]

Some people simply prefer the tape; it always worked for them and they see no reason to change. For others, tape is what you go to when when the silicone cap isn’t doing the job.