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RE: Pressure Safety Valve for Coke Drums

Home Forums Coking Maintenance Pumps, Valves, Rotary Joints, Cranes Valves Pressure Safety Valve for Coke Drums RE: Pressure Safety Valve for Coke Drums

#5718

In the coker unit that Ive been involved we have installed this kind of safety valve, they are working properly, I dont know if there are some problem with the minimum temperatura for this type of material (bellow), only for reference
 

 
Tag Number
 
 
 
 
 
 
 
 
 
 
 
 

 
P&ID Dwg. No.
 
 
 
 
 
 
 
 
 
 
 

 
Service
 
 
 
 
 
Coke Drum 
 
 

 
Line No. / Equip. No.
 
 
 
 
 
 
 
 
 
 

 
Full / Semi / Base Nozzle
 
Semi
 
 

 
Safety or Relief
 
 
 
Relief
 
 

 
Conv. or Bellows
 
 
 
Balanced Bellows
 
 

 
Bonnet Type
 
 
 
Closed
 
 

 
Size:  Inlet  |Outlet
 
 
 
12 INCH
12 INCH
 
 

 
Flange Rating / Scrwd: In | Out
900#
900#  
 
 

 
Flange Facing
 
 
 
RF
RF
 
 

 
Body and Bonnet
 
 
5 Cr – 1/2 Mo A217 / 304 SS
 
 

 
Seat and Disc
 
 
 
316 SS
 
 

 
Resilient Seat Seal
 
 
N/A
 
 

 
Guide and Rings
 
 
 
ASTM A297 Gr. HE / 316 SS
 
 

 
Spindle
 
 
 
 
 
416 SS
 
 

 
Spring
 
 
 
 
 
Alloy Steel
 
 

 
Bellows
 
 
 
 
 
Inconel 625
 
 

 
 
 
 
 
 
 
 
Note (**)
 
 

 
Cap:  Screwed / Bolted
 
Screwed
 
 

 
Lever:  Plain / Packed
 
 
No
 
 

 
Test Gag
 
 
 
 
No
 
 

 
Vent with Bug Screen
 
 
Yes
 
 

 
Bonnet / Spring Coating
 
Aluminized
 
 

 
Manufacturer
 
 
 
 
 
 
 
 
 
 
 

 
Model No.
 
 
 
 
 
 
 
12 V 12
 
 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
Outline Dimensions
 
 
Certified Dimension Outline
 
 

 
1.
Two relief valves required for adequate capacity
 
 

 


 

Code  |  Stamp
 
 
 
 
ASME VIII,  UV

Fire / P.F. / B.D. / C.W.F.
 
 
B.D. During Max Quench

Other
 
 
 
 
 
 
 
 
 
 
 
 
 

Fluid and State
 
 
 
 
Hydrocarbon Vapor / Steam

Discharges To
 
 
 
 
Coker Blowdown Drum 

Required Capacity
 
 
 
167747 lbs/hr (Note 1)

Mol. Wt. or Oper. Spec. Grav.
 
18.02
 
 
 
 
 

Press.:  Oper.  |  Set
 
 
psig
659660
661662

Temp.:  Oper.  |  Release
 
F
825
825

Design  Press. 
psig
Temp
F
681682
890

 
 
 
Constant
 
 
 
 
 
 

707708
Center Center
713714
Center Center

 
 
 

Back Press.
Variable
 
 
 
13 (Note 2)

 
psig
 
Built-up
 
 
 
749750

 
 
 
Total
 
 
 
28,0

% Blowdown
 
 
 
 
 
779780

% Allowable Overpressure
 
 
787788

Overpressure Factor
 
 
 
1.16

Compressibility Factor
 
 
1.0

Ratio of Specific Heats
 
 
1.28

Oper. Viscosity
 
 
 
cP
0.02

Wt. % Flash  |  MW of Vapor
 
 
 
 
 
 
 
 

Barometric Press.
 
 
psia
14.689

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 

915916
Center Center

 

Calculated Area
 
 
 
in
70.64
 

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