OK, just picked up a shiny new vacuum pump because the 16 year old SuperEvac died on the job.
7CFM JB pump.
Now, my current evac rig is 2 - 3/8" hoses, 1 - 1/4" hose when needed and VCRTs.
Following 'rules of thumb' that I was taught and information gleaned from this site:
a 1/4" hoses flows approximately 0.6 to 0.7 CFM.
a 3/8" flows approximately 4 times what a 1/4" hose will.
So, giving the benefit of the doubt to the 1/4" hose, 0.7 x 4 = 2.8 CFM per 3/8" hose.
2.8 x 2 is 5.6. Add another 1/4" hoses and you're up to 6.3 CFM which is DANG close to the actual pumps capacity of 7 CFM.
Will a larger hose benefit me in any substantial way and WHY?
Been pricing them and I've got a hard time parting with the coin that they want for a 1/2" hose for dubious benefit.