PE & PD Values Flashcards
These constants, equations, relationships will aid calculations in Chemical Engineering analyses.
capacity for underground fuel storage tank (Number)
45
Le/D for fully open globe (Number)
300
Le/D for fully open gate (Number)
around 7
Le/D for tee (Number)
90
Le/D for 45-elbow (Number)
45
Le/D for 180-close return (Number)
75
Le/D for couplings and unions (Number)
0
cap dia for >1.2 column dia (Number)
10
tube side ΔP for 1-2 vs 1-1 heat ex (Number)
8 (2^3)
constant power input, decrease impeller speed (Number)
1.2^5/3
assumed steam side heat transfer coefficient (Number)
7500
apex angle of conical heads (Number)
60
size of packings to be stacked not dumped (Number)
75
ΔP and superficial gas mass velocity (Number)
^2
(ΔP = G^2)
min baffle spacing in shell and tube (Number)
0.2D or 5 cms
power required with increase of dia (Number)
D^5
head to capacity for pipe flow (Number)
1/D^5
margin for plate tearing (Number)
1.5d
turbulent tube side heat transfer (Number)
G^0.8
thickness not requiring corrosion allowance (Number)
30
tube side film vs total resistance so overall coefficient is proportional with tube side (Number)
1
paddle to tank dia (Number)
0.8
vacuum of low pressure steam (Number)
650
dia to wall thickness ratio for “thin” vessel (Number)
> 10
dia to wall thickness ratio for “thick” vessel (Number)
<10
accentuated difficulty of liquid distribution (Number)
<7
min tube pitch (Number)
1.25
butt welded joints (Number)
3.8
ave velocity for 1-4 vs 1-1 heat ex (Number)
4
min ligament for outside dia (Number)
4/5
rate of washing vs final rate (Number)
0.25
static submergence for bubble cap (Number)
0.5
min plate spacing for dia >3 (Number)
18
min plate spacing for dia <3 (Number)
6
weld joint efficiency using code formula (Number)
0.8
ideal size of bubble cap for column of 3-6 dia (Number)
15
thickness of plates for lap joints (Number)
> 3
unusual length of heat ex tube (Number)
10
Re value where inside heat film is negligible (Number)
10000
min tray spacing in distillation (Number)
6
max size of raschig ring (Number)
1/30
distance of habitation to plants (Number)
25
air heater connected to 2 pass unit (Number)
2^0.8
single tube pass connected to 2 passes, ΔP (Number)
2^1.6
satisfactory value of operating vapor velocity (Number)
80
welded joint efficiency in chemical processes (Number)
0.85
