Stainless Steel Pipe Fittings

Lap Joint Flanges By

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Lap Joint Flanges By

Lap Joint flanges are used on piping fitted with with lapped pipe or with lap joint stub ends. The lap joint flange with the stub end assembly are normally used in systems requiring frequent dismantling for inspection and cleaning and where the ability to swivel flanges and to align bolt holes materially eases the erection of large diameter or unusually stiff piping. These flanges are also used in applications where there is a need to facilitate bolt alignment. These type of flanges are similar to slip-on flanges. The only difference is that it has a curved radius at the bore and face to accommodate a lap joint stub end. They may be used at all pressures and are available in a full size range. These lap joint flanges slip over the pipe, and are not welded. They are otherwise fastened to it. Here the bolting pressure is transferred to the gasket by the pressure of the flange against the back of the pipe lap.


•   Carbon Steel : ASTM A 105, ASTM A 181
•   Alloy Steel : ASTM A 182, GR F1, F11, F22, F5, F9, F91
•   Nickel Alloys : Monel 400 & 500, Inconel 600 & 625, Incolloy 800, 825, Hastelloy C22,C276 
•   Copper Alloys : Copper, Brass & Gunmetal 

Size : 1/8″ NB TO 48″NB. 
Class : 150#, 300#,400 #,600#,900#, 1500# & 2500 #. 


•   ANSI : ANSI B16.5, ANSI B16.47, MSS SP44, ANSI B16.36, ANSI B16.48
•   DIN :DIN2527, DIN2566, DIN2573, DIN2576, DIN2641, DIN2642, DIN2655, DIN2656, DIN2627, DIN2628, DIN2629, DIN 2631, DIN2632, DIN2633, DIN2634, DIN2635, DIN2636, DIN2637, DIN2638, DIN2673 
•   B.S : BS4504 , BS4504, BS1560, BS10 

Advantages of Lap Joint Flanges:
Lap Joint flanges have certain special advantages over other flanges. These are as follows:

•   Lap Joint flanges have the freedom to swivel around the pipe. This facilitates the lining up of opposing flange bolt holes. 
•   Lack of contact with the fluid inside the pipe leads to the greater durability of these flanges.
•   In piping systems which corrode or erode quickly, the lap joint flanges may be salvaged for re-use.
•   The pressure-holding capacity of lap joint flanges is little. But it is better than that of slip-on flanges.
•   The Lap Joint works as a backing ring on the stub.
•   The main advantage of lap joint flange is that the bolt holes can be aligned with the matching flange after the welds have been completed.
•   They allow rotational alignment capability.

Materials :
Nickel Alloy Lap Joint Flanges

• ASTM / ASME SB 564 / 160 / 472 
• UNS 10276 (HASTELLOY C 276 Lap Joint Flanges)
• UNS 2200 (NICKEL 200 Lap Joint Flanges)
• UNS 2201 (NICKEL 201 Lap Joint Flanges)
• UNS 4400 (MONEL 400 Lap Joint Flanges)
• UNS 8020 (ALLOY 20 Lap Joint Flanges)
• UNS 8825 INCONEL 825 Lap Joint Flanges)
• UNS 6600 (INCONEL 600 Lap Joint Flanges)
• UNS 6601 (INCONEL 601 Lap Joint Flanges)
• UNS 6625 (INCONEL 625 Lap Joint Flanges)

Copper Alloy Lap Joint Flanges 
ASTM / ASME SB 61 / 62 / 151 / 152.
C 70600 (CU -NI- 90/10) – Cupro Nickel Lap Joint Flanges 
C 71500 (CU -NI- 70/30) – Copper Nickel Lap Joint Flanges
UNS NO. C 92200, UNS NO. C 83600, UNS NO. UNS NO C 10100,
C 10200, C 10300, C 10800, C 12000, C 12200

Duplex Stainless Steel Lap Joint Flanges 
ASTM / ASME A/SA 182 UNS F 44, F 45, F51, F 53, F 55, F 60, F 61.

Alloy Steel Lap Joint Flanges – AS Lap Joint Flanges
ASTM SA 182 F1/F5/F9/F11/F22/F91

Carbon Steel Lap Joint Flanges – CS Lap Joint Flanges 
ASTMA 105 Gr. F42/46/52/56/60/65/70

Low Temperature Carbon Steel Lap Joint Flanges – LTCS Lap Joint Flanges
A350 LF2/A350 LF3

Value Added Services
• Hot Dip Galvanizing • Electro polish

Test Certificate
Mill Test Certificate as per EN 10204 / 3.1B
Duplex Stainless Steel : Duplex Stainless Steel Lap Joint Flanges – Duplex SS Lap Joint Flanges 

ASTM A 182 – Lap Joint Flanges
F 51 UNS S31803 Lap Joint Flanges
S32750 Lap Joint Flanges
S31500 Lap Joint Flanges
ASTM / ASME A/SA 182 UNS Lap Joint Flanges
F 44 Lap Joint Flanges
F 45 Lap Joint Flanges
F51 Lap Joint Flanges
F 53 Lap Joint Flanges
F 55 Lap Joint Flanges
F 60 Lap Joint Flanges
F 61 Lap Joint Flanges 
Carbon Steel Lap Joint Flanges – CS Lap Joint Flanges 
ASTM A105 Lap Joint Flanges
ASTM A 694-F42 Lap Joint Flanges
F46 Lap Joint Flanges
F52 Lap Joint Flanges
F60 Lap Joint Flanges
F65 Lap Joint Flanges
F70 Lap Joint Flanges

Copper Nickel Lap Joint Flanges – Cu-Ni Lap Joint Flanges

Source: Source: Zhejiang Yaang Pipe Industry Co., Limited (

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