ASME B16.5 Lap Joint Flange & ASME B16.9 Stub End Order

In February this year, we received an inquiry from a Chinese customer regarding ASME B16.5 lap joint flange and ASME B 16.9 stub end. With our many years of experience in steel sales, we quickly provided the customer with a quote, signed the contract on the same day, and completed the shipment a week later. Now this customer has become our long-term customer.

Introduction to Lap Joint Flange and Stub End:

ASME B16.5 lap joint flange is a removable flange designed to be used in conjunction with a stub end. It typically consists of two components: a flange ring and a stub end. After the stub end is welded to the pipe, the flange ring can rotate freely along its outer edge, facilitating alignment with bolt holes, making installation and disassembly highly convenient. This design not only reduces the risk of welding deformation but also facilitates use in pipeline systems requiring frequent disassembly or where space is limited. It is commonly used in stainless steel, alloy steel, and non-ferrous metal pipeline connections.

ASME B16.5 Lap Joint Flange Specifications:

Size Range	1/2″ – 24”/  DN15 – DN600
Pressure Rating	Class 150, 300, 600, 900, 1500, 2500lb
Standard	ASME B16.5
Stainless Steel	ASTM A182 F304/304L/304H, 316/316L, 310S, 317,347,904L
Duplex Stainless Steel	ASTM A182 F51, F53, F44
Carbon Steel	ASTM A105, 20#
Low Temperature Steel	ASTM A350 LF2, 16Mn
Pipeline Steel	ASTM A694 F42 / 46 / 56 / 60 / 65
Alloy Steel	ASTM A182 F11 / 12 / 5 / 9 / 91 / 92

Class 150 Lap Joint Flange Dimension:

 

Nominal Pipe Size		A	B	C	D	R	F	H	I	J	Weight
inch	mm	mm	mm	mm	mm	mm	mm	Holes	mm	mm	kg / piece
1/2	21.30	88.90	22.90	11.20	15.70	3.000	30.20	4	15.70	60.45	0.38
3/4	26.70	98.60	28.2	12.70	15.70	3.000	38.10	4	15.70	69.85	0.55
1	33.40	108.0	35. 10	14.20	17.50	3.000	49.30	4	15.70	79.25	0.76
11/4	42.20	117.3	43.70	15.70	20.60	4.800	58.70	4	15.70	88.90	1.01
11/2	48.30	127.0	50.00	17.50	22.40	6.400	65.00	4	15.70	98.60	1.30
2	60.30	152.4	62.50	19. 10	25.40	7.900	77.70	4	19.10	120.7	2.03
21/2	73.00	177.8	75.40	22.40	28.40	7.900	90.40	4	19.10	139.7	3.25
3	88.90	190.5	91.40	23.90	30.20	9.700	108.0	4	19.10	152.4	3.81
31/2	101.6	215.9	104.1	23.90	31.75	9.700	122.2	8	19.10	177.8	4.76
4	114.3	228.6	116.8	23.90	33.30	11.20	134.9	8	19.10	190.5	5.25
5	141.3	254.0	114.5	23.90	36.60	11.20	163.6	8	22.40	215.9	6.02
6	168.3	279.4	171.5	25.40	39.6	12.70	192.0	8	22.40	241.3	7.40
8	219. 1	342.9	222.3	28.40	44.50	12.70	246. 1	8	22.40	298.5	12.1
10	273.0	406.4	277.4	30.20	49.30	12.70	304.8	12	25.40	362.0	16.4
12	323.8	482.6	328.2	31.75	55.60	12.70	365.3	12	25.40	431.8	26.1
14	355.6	533.4	360.2	35. 10	79.25	12.70	400. 1	12	28.40	476.3	34.5
16	406.4	596.9	411.2	36.60	87.40	12.70	457.2	16	28.4	539.8	44.6
18	457.2	635.0	462.3	39.60	96.80	12.70	505.0	16	31.75	577.9	48.7
20	508.0	698.5	514.4	42.90	103.1	12.70	558.8	20	31.75	635.0	61.6
24	609.6	812.8	616.0	47.80	111.3	12.70	663.4	20	35.10	749.3	86.6

How to Insepct?

✅Visual inspection: Check whether the flange ring and short section fit together smoothly to ensure that the flange can rotate freely without excessive clearance.

✅Dimensional inspection: Use calipers, micrometers, and other tools to measure the inner diameter, outer diameter, thickness, and bolt hole center distance of the flange to ensure compliance with ASME standards.

✅Assembly inspection: Simulate actual installation to confirm that the bolts can pass through the flange holes smoothly.

Application Areas:

• Oil and Gas (Pipeline Transportation, Drilling Platforms, Refineries)
• Chemical Industry (Acid-Alkali Medium Pipelines, Reactor Connections)
• Power Industry (Steam/Circulating Water Pipelines for Thermal Power Plants and Nuclear Power Plants)
• Shipbuilding (Marine Pipeline Systems, Seawater Desalination Equipment)
• Industrial equipment (compressor, pump valve inlet/outlet connections)