Min THK - R-3.13 - TEMA 9th Ed
Min THK - R-3.13 - TEMA 9th Ed
Min THK - R-3.13 - TEMA 9th Ed
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Nominal Shell Diameter Carbon Steel Alloy *
Pipe Plate
6 (152) SCH. 40 1I 8 (3.2)
8-12 (203-305) SCH. 30 118 (3-2)
13-29 (330-737) SCH. STD 318 (9.5) 3116 (4.8)
30-39 (762-991) 7/16 (11.1) 114 (6-4)
40-60 (1016-1524) 112 (12.7) 5116 (7.9)
~
61-80 (1549-2032) 112 (12.7) 5116 (7.9)
81-100 (2057-2540) 112 (12.7) . 318 (9.5)
TABLE CB-3.13
MINIMUM SHELL THICKNESS
Dimensions in Inches (mm)
Minimum Thickness
Nominal Shell Diameter Carbon Steel Alloy *
Pipe Plate
6 (152) SCH. 40 1I8 (3.2)
8-12 (203-205) SCH. 30 1I 8 (3-2)
13-23 (330-584) SCH. 20 5/16 (7.9) 118 (3-2)
24-29 (610-737) 5/16 (7.9) 3116 (4.8)
30-39 (762-991) 318 (9.5) 114 (6.4)
40-60 (1016-1524) 7/16 (11.1) 114 ('3.4)
61-80 (1549-2032) 112 (12.7) 5116 (7-9)
81-100 (2057-2540) 112 (12.7) 318 (9.5)
*Schedule 5s is permissible for 6 inch (152 mm) and 8 inch (203 mm) shell diameters.
RCB-3.2 SHELL COVER THICKNESS
Nominal thickness of shell cover heads, before forming, shall be at least equal to the thickness of
the shell as shown in the applicable table.
8
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BAFFLE CUTS FOR MULTI-SEGMENTAL BAFFLES
DOUBLE SEGMENTAL
@ I III ::I
TABLE RCB-4.3
Standard Cross Baffle and Support Plate Clearances
Dimensions In Inches (mm) ,
Nominal Shell ID Design ID of Shell Minus Baffle OD
6-17 (152-432) 118 (3.2)
18-39 (457-991) 3/16 (4.8)
40-54 (1016-1372) 114 (6.4)
55-69 (1397-1753) 5/16 (7.9)
70-84 (1778-2134) 318 (9.5)
85-100 (2159-2540) 7/16 (11.1)
The design inside diameter of a pipe shell is defined as the nominal outside diameter of the pipe,
minus twice the nominal wall thickness. The design inside diameter of a plate shell is the specified
inside diameter. In any case, the design inside diameter may be taken as the actual measured
shell inside diameter.
RCB-4.4 THICKNESS OF BAFFLES AND SUPPORT PLATES
RCB-4.41 TRANSVERSE BAFFLES AND SUPPORT PLATES
The following tables show the minimum thickness of transverse baffles and support plates
applying to all materials for various shell diameters and plate spacings.
The thickness of the baffle or support plates for U-tube bundles shall be based on the
unsupported tube length in the straight section of the bundle. The U-bend length shall not
be considered in determining the unsupported tube length for required plate thickness.
TABLE R-4.41
BAFFLE OR SUPPORT PLATE THICKNESS
Dimensioris in Inches (mm)
Plate Thickness
Nominal Shell ID Unsupported tube length between central baffles. End spaces between tubesheets
and baffles are not a consideration.
24 (610) and Over 24 (610) Over 36 (914) Over 48 (1219) Over 60
Under to 36 (914) to 48 (1219) to 60 (1524) (1524)
Inclusive Inclusive Inclusive
6-14 (152-356) 118 (3.2) 3/16 (4.8) 114 (6.4) 318 (9.5) 318 (9.5)
15-28 (381-711) 3/16 (4.8) 114 (6.4) 318 (9.5) 318 (9.5) 112 (12.7)
29-38 (737-965) 114 (6.4) 5/16 (7.5) 318 (9.5) 112 (12.7) 518 (15.9)
39-60 (991-1524) 114 (6.4) 318 (9.5) 112 (12.7) 518 (15.9) 518 (15.9)
61-100 (1549-2540) 318 (9.5) 112 (12.7) 518 (15.9) 314 (19.1) 314 (19.1)
TABLE CB-4.41
BAFFLE OR SUPPORT PLATE THICKNESS
Dimensions in Inches(mm)
Plate Thickness
Nominal Shell ID Unsupportedtube length between central baffles. End spaces between
tubesheets and baffles are not a consideration. I
l = 1.5s
q/z
where
t = Minimum baffle plate thickness, in. (mm)
B = Table value as shown in Table RCB-9.132 (linear interpolation may be used)
q = Maximum pressure drop across baffle, psi (kPA)
S= Code allowable stress in tension, at design temperature, psi (kPa)
b = Plate dimension. See Table RCB-9.132, in. (mm)
a = Plate dimension. See Table RCB-9.132, in. (mm)
The designer shall consider the effects of pressure drop and unsupported span and
perform a calculation for the portion of the long baffle that will require the greatest
thickness. The longitudinal baffle shall be considered fixed along the two sides where it
is welded to the shell cylinder. It shall be considered simply supported along the sides
where it is supported by the tubesheet groove or transverse baffle.
R-4.423 LONGITUDINAL BAFFLE WELD SIZE
Welded-in longitudinal baffles shall be attached with fillet welds on each side with a
minimum leg of ?4t from Paragraph R-4.422. Other types of attachments are allowed
but shall be of equivalent strength.
CB-4.42 LONGITUDINAL BAFFLES
CB4.421 LONGITUDINAL BAFFLES WITH LEAF SEALS
Longitudinal carbon steel baffles with leaf (or other type) seals shall not be less than
114" (6.4 mm) nominal metal thickness.
TABLE RCB-4.52
MAXIMUM UNSUPPORTED STRAIGHT TUBE SPANS
Dimensions in Inches (mm)
Tube Materials and Temperature Limits " F ( " C)
Tube OD Carbon Steel & High Alloy Steel, 750 Aluminum &Aluminum Alloys, Copper &
(399) Copper Alloys, Titanium Alloys At Code
Low Alloy Steel, 850 (454) Maximum Allowable Temperature I
Nickel-Copper, 600 (316)
Nickel, 850 (454)
Nickel-Chromium-Iron, 1000 (538)
114 (6.4) 26 (660) 22 (559)
318 (9.5) 35 (889) 30 (762)
112 (12.7) 44 (1118) 38 (965)
518 (15.9) 52 (1321) 45 (1143)
314 (19.1) 60 (1524) 52 (1321)
7/8 (22.2) 69 (1753) 60 (1524)
1 (25.4) 74 (1880) 64 (1626)
1-114 (31.8) 88 (2235) 76 (1930)
1-112 (38.1) 100 (2540) 87 (2210)
2 (50.8) 125 (3175) 110 (2794)
2-112 (63.5) 125 (3175) 110 (2794)
3 (76.2) 125 (3175) 110 (2794)
Notes:
(1) Above the metal temperature limits shown, maximum spans shall be reduced in direct
proportion to the fourth root of the ratio of elastic modulus at design temperature to
elastic modulus at tabulated limit temperature.
(2) In the case of circumferentially finned tubes, the tube OD shall be the diameter at the
root of the fins and the correspondingtabulated or interpolated span shall be reduced
in direct proportion to the fourth root of the ratio of the weight per unit length of the
tube, if stripped of fins to that of the actual finned tube.
(3) The maximum unsupported tube spans in Table RCB-4.52 do not consider potential
flow induced vibration problems. Refer to Section 6 for vibration criteria.
RCB-4.53 BAFFLE SPACING
Baffles normally shall be spaced uniformly, spanning the effective tube length. When this
is not possible, the baffles nearest the ends of the shell, andlor tubesheets, shall be located
as close as practical to the shell nozzles. The remaining baffles normally shall be spaced
uniformly.
RCB4.54 U-TUBE REAR SUPPORT
The support plates or baffles adjacent to the bends in U-tube exchangers shall be so
located that, for any individual bend, the sum of the bend diameter plus the straight lengths
measured along both legs from supports to bend tangents does not exceed the maximum
unsupported span determined from Paragraph RCB-4.52. Where bend diameters prevent
compliance, special provisions in addition to the above shall be made for support of the
bends.
RCB4.55 SPECIAL CASES
When pulsating conditions are specified by the purchaser, unsupported spans shall be as
short as pressure drop restrictions permit. If the span under these circumstances
approaches the maximum permitted by Paragraph RCB-4.52, consideration should be
given to alternative flow arrangements which would permit shorter spans under the same
pressure drop restrictions.