pipe fitting elbow-butweld elbow-long radius elbow,

Specification

Pipe Fitting Elbow Introduction

Size:	OD: 1/2"-24" seamless, 26"-60" welded
	WT: SCH5S,10S,10,40S,STD,XS,80S,XXS,40,60,80,160,XXS
	30° 45° 60° 90° 180°,etc
	LR/long radius=1.5D,SR/Shrot radius=1D, various radius: 3D,4D,5D,6D,7D
Pipe Standard:	ANSI B16.9, EN10253-4, DIN 2605, GOST 17375, JIS B2313, MSS SP 75
	Stainless Steel A403 WP 304/L,316/L,321,310S,347H,317,316Ti,904L
	ASTM A234 WP1/5/9/11/12/22/91
	Duplex stainless steel: UNS31803, SAF2205, UNS32205, UNS31500
Furface:	Pickled,sand blasting, rolling blast,brighten,polished,galvinizing,vanished

Steel Pipe Elbow is a key parts in a piping system for to change the fluid flow direction. It is used to connect two pipes with same or different nominal diameters, and to make the pipe turn to a certain direction of 45 degree or 90 degree or 180 degree.

Applications of Pipe Elbow Fittings:
Pipe elbows are manufactured to be used in flow lines for gases, fluids in industrial processes, medical, construction and many other specialized applications.

The elbows are constructed of heavy materials for rigid applications like extreme high/low temperature resistance etc.

The elbows are specifically designed for use on process and control systems, instrumentation, and equipment used in chemical, petroleum, fluid power, electronic and pulp and paper plants.

Types of Steel Pipe Elbows

The ends may be machined for butt welding (SW) or socketed welding(SW) etc.

Short Radius (SR) Elbow is also called SR elbow, – means the radius is 1.0 times the pipe diameter

Short radiu 45°Elbow: Short radius 45° elbow changes the direction by 45 degrees.

Short radius 90°Elbow: Short Radius 90° elbow is same as LR90 except for the measurement between end of elbow to center line is 1 x NPS.

Short radius 180° Elbow: Short Radius 180° return bend allows complete reversal of flow

Sizes:

Seamless elbow: 1/2"-24" DN15-DN600
Welding elbow: 6"-72" DN150-DN1800
Wall thickness: Sch5-Sch160 XXS

Long radius elbow is the elbow which the radius of curvature of is 1.5 times the diameter of the pipe; if the radius of curvature is greater than 1.5 times, the long radius elbow will be called the bend. The short radius elbow means that the radius of curvature of the elbow equals the diameter of the pipe, or 1 time the diameter of the pipe in common words. D is used to represent the diameter of the elbow.
Long Radius (LR) Elbow is also called LR elbow – means the radius is 1.5 times the pipe diameter
L/R 45°Elbow: Long radius 45 degree elbow changes the direction by 45 degrees.
L/R 90°Elbow: Long radius 90 degree elbow changes the direction by 90 degrees.
L/R 180°Elbow: Long Radius 180 degree return bend allows complete reversal of flow.

Sizes:

Seamless elbow: 1/2"-24" DN15-DN600

Welding elbow: 6"-72" DN150-DN1800

Wall thickness: Sch5-Sch160 XXS

Nominal pipe size		Outside Diameter at Bevel		Center to End			Center to Center		Back to Faces
				45°Elbows	90°Elbows		180°Return
				H	F		P		K
DN	INCH	Series A	Series B	LR	LR	SR	LR	SR	LR	SR
15	1/2	21.3	18	16	38	-	76	-	48	-
20	3/4	26.9	25	16	38	-	76	-	51	-
25	1	33.7	32	16	38	25	76	51	56	41
32	11/4	42.4	38	20	48	32	95	64	70	52
40	11/2	48.3	45	24	57	38	114	76	83	62
50	2	60.3	57	32	76	51	152	102	106	81
65	21/2	76.1(73)	76	40	95	64	191	127	132	100
80	3	88.9	89	47	114	76	229	152	159	121
90	31/2	101.6	-	55	133	89	267	178	184	140
100	4	114.3	108	63	152	102	305	203	210	159
125	5	139.7	133	79	190	127	381	254	262	197
150	6	168.3	159	95	229	152	457	305	313	237
200	8	219.1	219	126	305	203	610	406	414	313
250	10	273.0	273	158	381	254	762	508	518	391
300	12	323.9	325	189	457	305	914	610	619	467
350	14	355.6	377	221	533	356	1067	711	711	533
400	16	406.4	426	253	610	406	1219	813	813	610
450	18	457.2	478	284	686	457	1372	914	914	686
500	20	508.0	529	316	762	508	1524	1016	1016	762
550	22	559	-	347	838	559	Note: 1. Do not use the figures in the parenthesis as far as possible 2. Please first select A series.
600	24	610	630	379	914	610
650	26	660	-	410	991	660
700	28	711	720	442	1067	711
750	30	762	-	473	1143	762
800	32	813	820	505	1219	813
850	34	864	-	537	1295	864
900	36	914	920	568	1372	914
950	38	965	-	600	1448	965
1000	40	1016	1020	631	1524	1016
1050	42	1067	-	663	1600	1067
1100	44	1118	1120	694	1676	1118
1150	46	1168	-	726	1753	1168
1200	48	1220	1220	758	1829	1219

Process

Elbow process

Tests

Visual inspection:

Generally based on the naked eye observation, sometimes with a 5-20 times magnifying glass for observation. Through visual inspection, surface defects of weld elbow welds, such as undercuts, welds, surface cracks, pores, slag inclusions, and weld penetration, can be found. The dimensions of the weld can also be measured using a weld detector or template.

Non-destructive testing:

Inspection of defects such as slag inclusions, pores and cracks hidden inside the weld. At present, the most common use is X-ray inspection, as well as ultrasonic flaw detection and magnetic flaw detection. Ultrasonic flaw detection is much simpler than X-ray photography and is therefore widely used. However, ultrasonic flaw detection often can only be judged based on operational experience, and can not leave a test basis. For internal defects that are not deep from the surface of the weld and extremely small cracks on the surface, magnetic flaw detection can also be used.

Hydraulic test and air pressure test:

For pressurized containers requiring sealing, hydraulic pressure test and/or air pressure test shall be carried out to check the sealing and pressure bearing capacity of the weld. The method is to inject 1.25-1.5 times working water or a working pressure gas (mostly air) into the container for a certain period of time, then observe the pressure drop in the container and observe whether there is leakage outside. According to these, it can be assessed whether the weld is qualified.

The mechanical performance test of the elbow:

Mon-destructive testing can find the inherent defects of the weld, but can not explain the mechanical properties of the metal in the heat affected zone of the weld, so sometimes the welded joint should be subjected to tensile, impact, bending and other tests. These tests were performed by the test panels. The test panels used are preferably welded together with the longitudinal joints of the cylinder to ensure consistent construction conditions. The test panels were then tested for mechanical properties. In actual production, only welded joints of new steel grades are generally tested in this respect.

Packing & Delivery

steel pipe elbow steel pipe elbow packing

Elbow

Tolerance table

NOMINAL PIPE SIZE NPS	ANGULARITY TOLERANCES	ANGULARITY TOLERANCES	ALL DIMENSIONS ARE GIVEN IN INCHES. TOLERANCES ARE EQUAL PLUS AND MINUS EXCEPT AS NOTED.
	Off Angle Q	Off Plane P	(1) Out-of-round is the sum of absolute values of plus and minus tolerance. (2) This tolerance may not apply in localized areas of formed fittings where increased wall thickness is required to meet design requirements of ASME B16.9. (3) The inside diameter and the nominal wall thicknesses at ends are to be specified by the purchaser. (4) Unless otherwise specified by the purchaser, these tolerances apply to the nominal inside diameter, which equals the difference between the nominal outside diameter and twice the nominal wall thickness.
½ to 4	0.03	0.06
5 to 8	0.06	0.12
10 to 12	0.09	0.19
14 to 16	0.09	0.25
18 to 24	0.12	0.38
26 to 30	0.19	0.38
32 to 42	0.19	0.50
44 to 48	0.18	0.75

General Tolerances forpipe elbow of ASME B16.9

NPS	DN	O.D	I.D	Off Angle, Q	Off Plane, P
1/2~2-1/2	15~65	+1.6, -0.8	±0.8	±1	±2
3~3-1/2	80~90	±1.6	±1.6	±2	±4
4	100	±1.6	±1.6	±3	±5
5~8	125~200	+2.4, -1.6	±1.6	±3	±6
10~18	250~450	+4.0, -3.2	±3.2	±4	±10
20~24	500~600	+6.4, -4.8	±4.8	±5	±10
26~30	650~750	+6.4, -4.8	±4.8	±5	±13
32~48	800~1200	+6.4, -4.8	±4.8	±5	±19

* All dimensions are in mm unit. NPS: Nominal Pipe Size; DN: Nominal Diameter.
* O.D: outside diameter at bevel; I.D: inside diameter at end; Both P & Q are angularity tolerances.
* A minimum wall thickness of 87.5% should apply unless otherwise specified by the purchaser.

Tolerances of Center-to-End & Overall Length Dimensions

NPS	DN	*I	*II	*III	*IV
1/2~2-1/2	15~65	±2	±3	±2	±3
3~3-1/2	80~90	±2	±3	±2	±3
4	100	±2	±3	±2	±3
5~8	125~200	±2	±3	±2	±6
10~18	250~450	±2	±3	±2	±6
20~24	500~600	±2	±3	±2	±6
26~30	650~750	±3	±6	±5	±10
32~48	800~1200	±5	±6	±5	±10

* All dimensions are in mm unit.
* I refers to the tolerances for center-to-end dimensions of 90° & 45° long and short radius elbows and tees, A, B, C, M.
* II refers to the tolerances for center-to-end dimensions of 3D radius elbows, A, B.
* III refers to the tolerances for overall length of reducers and lap joint stub ends, F, H.
* IV refers to the tolerances for overall length of caps, E.

Chemical composition

Chemical Composition (%) of ASTM A420

This specification covers wrought carbon steel and alloy steel fittings of seamless & welded construction intended for use at low temperatures. It covers four grades WPL6, WPL9, WPL3 & WPL8 depending upon chemical composition. Fittings WPL6 are impact tested at temp – 50° C, WPL9 at -75° C, WPL3 at -100° C and WPL8 at -195° C temperature.

The allowable pressure ratings for fittings may be calculated as for straight seamless pipe in accordance with the rules established in the applicable section of ASME B31.3.

The pipe wall thickness and material type shall be that with which the fittings have been ordered to be used, their identity on the fittings is in lieu of pressure rating markings.

Steel No.	Type	Chemical composition
Steel No.	Type	C	Si	S	P	Mn	Cr	Ni	Mo	Other	ób	ós	δ5	HB
WPL6	0.3	0.15-0.3	0.04	0.035	0.6-1.35	0.3	0.4	0.12	Cb:0.02;V:0.08	415-585	240	22
WPL9	0.2		0.03	0.03	0.4-1.06		1.6-2.24			435-610	315	20
WPL3	0.2	0.13-0.37	0.05	0.05	0.31-0.64		3.2-3.8			450-620	240	22
WPL8	0.13	0.13-0.37	0.03	0.03	0.9		8.4-9.6			690-865	515	16