F304 F316L UNS 31803 A105 Stainless/Duplex/Alloy/Carbon Steel LJF
Lap Joint Flange
A lap-joint flange requires two piping components for each side of
the flanged connection, a stub end and a loose backing flange. The
loose backing flange fits over the outside diameter of the stub
end, which is butt-welded to the pipe. The backing flange is not
welded to the pipe, and it can be rotated, which is particularly
useful when it is necessary to orientate flanges during erection.
Also, as the backing flange does not come in contact with the
process fluid, it can made of a less corrosive-resistant material.
For example, if the process is corrosive and requires the pipe to
be of stainless steel, as in ASTM A312 TP316L, then the stub end
must also be made of SS 316L; however, the backing flange can be
made of the cheaper ASTM A105.
This method of jointing is not as robust as a weld neck flange but
is superior to screwed, socket weld, and slip on connections;
however, it is more expensive to execute, because it require a
full-penetration butt weld and requires two components.
ANSI/ASME B16.5 Lap Joint Flange Specification
| Dimensions | ANSI B16.5, ANSI B16.47 Series A & B, MSS SP44, ASA, API-605, AWWA,
Custom Drawings |
| Size | 1/2″ (15 NB) to 48″ (1200NB) |
| Class | 150 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS, 2500 LBS, DIN
Standard ND-6,10, 16, 25, 40 Etc. |
| DIN | DIN2527, DIN2566, DIN2573, DIN2576, DIN2641, DIN2642, DIN2655,
DIN2656, DIN2627, DIN2628, DIN2629, DIN 2631, DIN2632, DIN2633,
DIN2634, DIN2635, DIN2636,DIN2637, DIN2638, DIN2673 |
| BS | BS4504 , BS4504, BS1560, BS10 |
| Coating/Surface Treatment | Antirust Paint, Oil Black Paint, Yellow Transparent, Zinc Plated,
Cold and Hot Dip Galvanized |
| Flange Face Type | Flate Face (FF), Raised Face (RF), Ring Type Joint (RTJ) |
| Value Added Services | CNC Machining, Customised Flanges |
ASME B16.47 Lap Joint Flange Material SpecificationStainless Steel Lap Joint Flanges :
ASTM A 182, A 240 F 304, 304L, 304H, 316, 316L, 316Ti, 310, 310S,
321, 321H, 317, 347, 347H, 904L
Duplex & Super Duplex Steel Lap Joint Flanges :
ASTM / ASME A/SA 182 F 44, F 45, F51, F 53, F 55, F 60, F 61
Carbon Steel Lap Joint Flanges :
ASTM / ASME A/SA 105 ASTM / ASME A 350 , ASTM A 181 LF 2 / A516
Gr.70 A36, A694 F42, F46, F52, F60, F65, F706
Low Temperature Carbon Steel Lap Joint Flanges : ASTM A350, LF2, LF3
Alloy Steel Lap Joint Flanges :
ASTM / ASME A/SA 182 & A 387 F1, F5, F9, F11, F12, F22, F91
Copper Alloy Steel Lap Joint Flanges : ASTM SB 61 , SB62 , SB151 , SB152 UNS No. C 70600 (Cu-Ni 90/10), C
71500 (Cu-Ni 70/30), UNS No. C 10100, 10200, 10300, 10800, 12000,
12200
Nickel Alloy Lap Joint Flanges :
ASTM SB564, SB160, SB472, SB162 Nickel 200 (UNS No. N02200), Nickel
201 (UNS No. N02201), Monel 400 (UNS No. N04400), Monel 500 (UNS
No. N05500), Inconel 800 (UNS No. N08800), Inconel 825 (UNS No.
N08825), Inconel 600 (UNS No. N06600), Inconel 625 (UNS No.
N06625), Inconel 601 (UNS No. N06601), Hastelloy C 276 (UNS No.
N10276), Alloy 20 (UNS No. N08020)
