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
thickness for length/dia ratio, 125 design stress (Number)
10 mm
safe height to dia fuel storage tank (Number)
1
bubble cap dia with column dia of 1.5 to 4.5 (Number)
100
shank dia given that 25 hole dia (Number)
23
stress concentration ngeligible at this hole dia (Number)
two
condensing coefficient of horizontal vs. vertical (Number)
thrice
dia for duct of square cross-section | liquid depth in agitation tank (Number)
d
Unwin’s formula (Number)
d=1.6√t
min Fr desired for heat ex design (Number, 2nd lowest)
0.8
area increase for raschig to lessing (Number, 2nd lowest)
20
min residence time in downspout (Number, 2nd lowest)
8
min residence time in down comer (Number, 2nd lowest)
5
outside dia not recommended for fouling fluid (Number, 2nd lowest)
19
viscosity where baffle can be eliminated (Number, 2nd lowest)
600
min shell thickness for elastic stability (Number, 2nd lowest)
5
brass valves (Number, 2nd lowest)
<2
dia of normal screwed fittings (Number, 2nd lowest)
3
max liquid gradient (Number, 2nd lowest)
12.5 mm
max saddle packing (Number, 2nd lowest)
1/15
Poisson’s ratio for structural and pressure vessel (Number, 2nd lowest)
0.3
seamless pipe joint efficiency (Number, 2nd lowest)
1
min clearance for weir and last row of bubble cap (Number, 2nd lowest)
7.5
inclined long tube vertical evaporator (Number, 2nd lowest)
45
calendria tube height (Number, 2nd lowest)
2
hydrostatic testing of welded pipe (Number, 2nd lowest)
1.5
buffer to tube wall thickness (Number, 2nd lowest)
twice
rotary vacuum drum speed (Range)
0.1-2
max liquid gradient (Range)
0.5-1.25”
dia bubble cap standard (Range)
6&4
baffle spacing (Range)
/5-2-5
D/5 or min 2 to 5D = D/5 0.2D for min
tube pitch vs tube dia (Range)
1.25-1.5
safe distance between hazardous chemicals (Range)
1-1.5
tube length to shell dia (Range)
4-8
steam velocity in pipes (Range)
80-100
hold-up in rotary drier (Range)
0.05-0.15
Indian standard code for testing pressure (Range)
1.5-2
downtake to cross-sectional area for calendria (Range)
0.5-1
liquid redistributors position for raschig rings (Range)
2.5-3
countercurrent rotary drier slope (Range)
0.15
propeller agitator to tank dia (Range)
0.15-0.30
NTU for rotary driers (Range)
1.5-2.5
length of straight rectangular weir (Range)
0.6-0.8
optimum to min reflux ratio (Range)
1-1.5
total riser to cross-sectional area (Range)
0.1-0.2
commercial HETP (Range)
0.4-0.9
max size of pal ring (Range)
1/10-1/15
baffle width to tank dia (Range)
0.1-0.12
ΔP across continuous rotary drier (Range)
250-500
triangular pitch for sieve tray holes (Range, 2nd lowest)
2.5-5
min carbon steel shell thickness (Range, 2nd lowest)
5-11
ΔP for packed absorption tower (Range, 2nd lowest)
20-40
operating ΔP for bag filter (Range, 2nd lowest)
50-150
propeller agitator diameter (Range, 2nd lowest)
15-30
liquid redistributors position for saddle packing (Range, 2nd lowest)
5-8
paddle agitator speed (Range, 2nd lowest)
20-100
paddle blade width times the paddle dia (Range, 2nd lowest)
0.1-0.25
plate thickness for plate heat ex (Range, 2nd lowest)
1.25-3.12
rotary length to dia (Range, 2nd lowest)
4-10
sieve tray hole dia (Range, 2nd lowest)
3-12.5
factor of safety (Range, 2nd lowest)
15-20
pitch vs outside dia of bubble cap (Range, 2nd lowest)
1.3-2
ΔP for commercial packed scrubber (Range, 2nd lowest)
17-34
water velocity in pipes (Range, 2nd lowest)
1-2
onset ΔP for flooding (Range, 2nd lowest)
50-75
flight height in rotary drier (Range, 2nd lowest)
0.08-0.12
non-foaming vapor velocity (Range, 2nd lowest)
0.6-0.7
impeller dia to turbine agitator (Range, 2nd lowest)
0.3-0.5
ΔP per tray (Range, 2nd lowest)
0.07-0.12
sieve plate hole to dia (Range, 2nd lowest)
2.5-4
frame thickness for plate and frame (Range, 2nd lowest)
0.25-8
rotary cylinder shell thickness (Range, 2nd lowest)
6-8
