Page 498 - APPLIED PROCESS DESIGN FOR CHEMICAL AND PETROCHEMICAL PLANTS, Volume 1, 3rd Edition

464 Applied Process Design for Chemical and Petrochemical Plants
I'- Spec. Dwq, No.

Job No.. _ ------
� of Po ;es
Pa qe
B/M No. Unit Price
No. Unih
SAFETY VALVE SPECIFICATIONS Item No.
DESCRIPTION
Standard Stamdard
Mako Modol Type•Back Press.
If L 6 Vapor
Size (Inlet x Oriflee No, x Outlet) ( x x Phose
�
1 75 PSIG ) 3 1 7 0
Set Pres, ( )@ 'F Full Flow Back Pross. PSIG
2.02 ?..853
Req'd Orifice Area Sq. In.: Selected Orifice Area Sq, In,
2 Screwed Cao. No Test Gaq No Liftinq Gear
Acce1aorfe1
250#-4" Raised
Inlet Nozzle: Pr•••· Clau Facin;
125 #- 6" Raised
Outlet Nonie: Preu, Clou Facing
250# 450
Mfgr'1, Roting PSIG (Mox)<. , �, 1 2 5# ( OU t 1 et) PSIG (M;n)@ 300 'F
1 2
Ref.,, to lnltfal Ve11el relief pressure. Refers to cop type, lifting gaar, gag, otc:.
MATERIALS
Cast Iron Bronze
Body and Bonnet Trim
9ronze Bellows None
Nonie and Dl1c
Carbon Stee 1, cadium plated, or equal
Spring
REMARKS
Uoo throo•way wive (YH) (No) No

PROCESS RATING DATA
I Location n ..... �"".'11,--,...�t,,....,..,. C"L.-11 Flow tt.::to � ure
• Fluid PDC Basad On Operations Vesse 1 Max.
z SyaNm Oper. Pr•••· 60 PSIG@ 347 'F: MW• 113.5
. I RM'd Cop, 22, 500 Lbs/Hr,@ 347 'F* Phase: Liquid Lbs/Cu. Ft,
Dens.•
• • . ,... Liq, Vi1co1ity* SSU :XA«u..i, lc,tiol( ]Q %: Back Pren. Corr. Factor
overpressure
...
. -
..
• R•fen to properties at S.t Prea1ure
.
u CALCULATIONS
�
..c a '
I
� � Use: A= W(Z T/M)i c KdP Kb
� Since data for c/cv not readily available, use k = 1.001 and c = 315, z = 1.0, Kb=l ,0
0
�
0
.,, p ( at relieving condition) = (75)(1.1) + 14.7 = 97.2 psi a --
• I T = 347 + 460 = 807 R
u
iii 0 "ti
z � ,,.
A = 22, 500[ ( 1) ( 807) I 113. 5] t I (315) (0.953) (97,2) (1.0) .
0
. I A = 2.055 Sq. In, �
?
�
• ,... Note that critical flow conditions apply, since relieving pressure of 97.2 psi a z
is over twice the backpressure of 14.7 psi a. 3 <T
=
--
By I Chk'd I App. I Rev. 1 Rev, J Rev,
Dot• I I I I l
Figure 7-33. Safety relief valve specification for process overpressure example.