raoul,
I am not sure if you are still interested in pumping but let me lend what I know (or think)
I like to split my pumping into 2 15 minute sets with a nice 10 minute jelq in the middle.
I you get some nice wood you can pump up to about 5hgs max (let comfort be your guide) and just rest for 10 to 15 minutes.
Keep an eye on the gauge so that it does not drop too low.
When time is up, release the pressure and spin jelq your cock to replace the blood. With about 50% wood you can then do some nice slooooow jelqs (concentrate on quality). After about 10 minutes of jelqing you can go back under pressure and repeat the previous session. I don’t like to exceed 30 minutes under pressure per session.
You can do two a day if you have the time.
Sometime in 2005: Bpel 5.7, eg 4.3: 7/15/07 bpel=6.1, eg 4.6
Now bpel 6.50, eg 5.30 bpfsl 6.50
Goal bpel 7.0 - 7.5, eg 5.5