Fig. 18.4 Pumpfillingand drainage:(a) tangentialspiralhousing,ventingOK, without
drainage;(b) radialspiralhousing,ventingoptimal,withoutdrainage;(c) tangentialspiral
housing,ventingpoor,withdrainage;(d) radialspiralhousing,ventingpoor,with
drainage;(e) tangentialspiralhousing,ventingOK,withdrainage;(f) radialspiral
housing,ventingoptimal,withdrainage.
Improving the hygienic designof pumps 283