What Is Lap Joint Stub End ?

What Is Lap Joint Stub End ?

Lap joint stub end also called Lap Joint and Vanstone Flared Lap. It is fitting used in place of welded flangewhere rotating back up flange is desired.

A rotating back up flange seats itself against the back surface of the Stub End. When bolts are added, the clamping action of the bolts presses the rotating back up flange against the back of the Stub End. The gasket surface of the Stub End then presses against a gasket and another gasket surface providing joints like standard flange joints. The seal is made by the gasket surface of the stub end alone, the flange only provides the clamping pressure on the joint.

Lap joint stub ends slide directly over the pipe and are most commonly used with stub end fittings. A pipe is usually welded to the Stub End and the Lap Joint pipe flange is free to rotate around the stub end. The benefit of this is that there will not be any issues with bolt hole alignment. Lap Joint pipe flanges are often used for applications that require frequent dismantling.

Drawing of Lap Joint Stub Ends

Size: 1/2″ – 24″

Types: Type A, Type B, Type C, Type D

Material:

Carbon: SA234 WPB, SA234 WPC,SA42 WPL6, SA42 WPL3, WP1. MSS-SP75 

        WPHY,WPHY 46,WPHY 52,WPHY 56,WPHY 60,WPHY 65, WPHY 70 

Stainless: ASTM/ASME SA403 304,304L ,316, 316L, WP304L, 3 WP316 WP347 (H) ,WP317 (L),WP321.

DIN 1.4301, 1.4306, 1.4401, 1.4571 

JIS SUS304,SUS304, SUS304L, SUS316, SUS316

Alloy: ASTM/ASME SA234 WP12, WP11,WP22, WP5, WP9, WP91.

         ASTM B361 GR.3003-6061, 

         ASTM B366 UNS N04400,N08800, N08825 N1001-N10276-N10665, WPT2-WPT12.

         ASTM 182 F1, F5, F6, F7, F9, F11, F12, F22, F51.

        16MnR Cr5Mo 12Cr1MoV 10CrMo910 15CrMo 12Cr2Mo1, St45.8

Others: Copper, Aluminium,Brass,Titanium, Nickel,Nichrome, Al.Bronze Phosphorous Bronze

Usage: Petroleum, Chemical, Power, Gas, Metallurgy, Ship-building, Construction, ect.

Packing: Plywood Case/ Pallet/ other

Nominal Pipe Size	Outside Diameter at Bevel	Length	Radius of Fillet		Diameter of Lap
			A	B
NPS	D	L	R		G
1/2 3/4 1	21.3 26.7 33.4	51 51 51	3.0 3.0 3.0	0.8 0.8 0.8	35 43 51
11/4 11/2 2	42.2 48.3 60.3	51 51 64	5.0 6.0 8.0	0.8 0.8 0.8	64 73 92
21/2 3 31/2	73.0 88.9 101.6	64 64 76	8.0 10.0 10.0	0.8 0.8 0.8	106 127 140
4 5 6	114.3 141.3 168.3	76 76 89	11.0 11.0 13.0	0.8 1.6 1.6	157 185 218
8 10 12	219.1 273.0 323.8	102 127 152	13.0 13.0 13.0	1.6 1.6 1.6	270 324 381
14 16 18	355.6 406.4 457.0	152 152 152	13.0 13.0 13.0	1.6 1.6 1.6	413 470 533
20 22 24	508.0 559.0 610.0	152 152 152	13.0 13.0 13.0	1.6 — 1.6	584 641 692
●Minimum lap thickness shall not be less than nominal wall thickness. ●Contact faces of stub ends shall have a concentric serration or spiral according to the purchaser’s requirements. ●These lengths and radius apply for schedule 40s or thinner stainless steel pipes. ●Radius of fillet B is only effective to MSS SP-43 lap joint stub ends.

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