Butt Weld Fittings general

A pipe fitting is defined as a part used in a piping system, for changing direction, branching or for change of pipe diameter, and which is mechanically joined to the system. There are many different types of fittings and they are the same in all sizes and schedules as the pipe.

Fittings are divided into three groups..

• Buttweld (BW) fittings whose dimensions, dimensional tolerances et cetera are defined in the ASME B16.9 standards. Light-weight corrosion resistant fittings are made to MSS SP43.
• Socket Weld (SW) fittings Class 3000, 6000, 9000 are defined in the ASME B16.11 standards.
• Threaded (THD), screwed fittings Class 2000, 3000, 6000 are defined in the ASME B16.11 standards.

Standard Buttweld Fittings

Applications of Buttweld Fittings

A piping system using buttweld fittings has many inherent advantages over other forms.

• Welding a fitting to the pipe means it is permanently leakproof
• The continuous metal structure formed between pipe and fitting adds strength to the system
• Smooth inner surface and gradual directional changes reduce pressure losses and turbulence and minimize the action of corrosion and erosion
• A welded system utilizes a minimum of space

Bevelled Ends

The ends of all buttweld fittings are bevelled, exceeding wall thickness 4 mm for austenitic stainless steel, or 5 mm for ferritic stainless steel. The shape of the bevel depending upon the actual wall thickness. This bevelled ends are needed to be able to make a ‘Butt weld’.

ASME B16.25 covers the preparation of buttwelding ends of piping components to be joined into a piping system by welding. It includes requirements for welding bevels, for external and internal shaping of heavy-wall components, and for preparation of internal ends (including dimensions and dimensional tolerances). These weld edge preparation requirements are also incorporated into the ASME standards (e.g., B16.9, B16.5, B16.34).

Material and Performance

The most common materials used in fittings produced is carbon steel, stainless steel, cast iron, aluminium, copper, the various types of plastics, etc..

In addition, fittings, like pipes, for specific purposes sometimes internally equipped with layers of materials of a completely different quality as the fitting themselves, which are ‘lined fittings’.

The material of a fitting is basically set during the choice of the pipe, in most cases, a fitting is of the same material as the pipe.

Buttweld Fittings

Japanese Industrial Standard – JIS B2311-82.

The standard specifies steel butt-welding pipe fittings which are generally used for ordinary piping in JIS G3452, for steam, water, oil, gas, etc., at relatively low pressures.

Materials : The fittings to this standard are made from materials in accordance with JIS G3452.

Pressure Ratings : The fittings are free from leakage at hydrostatic pressure up to a maximum of 2.5 MPa.

Welding End Preparations : Bevel dimensions and tolerances conform to those shown in the diagram. Fittings with a basic thickness below 4 mm have plain unbeveled ends.

Details of Buttweld Fittings to JIS B2311-82 (SGP – All Sizes are Welded)

 90° ELBOWS LONG RADIUS

Nominal Pipe Sizemm	Outside DiameterODmm	SGP	A	Mass (kg)(approx.)90EL SGP
Inside DiameterID	Wall ThicknessT
15	21.7	16.1	2.8	38.1	0.08
20	27.2	21.6	2.8	38.1	0.10
25	34.0	27.6	3.2	38.1	0.15
32	42.7	35.7	3.5	47.6	0.25
40	48.6	41.6	3.5	57.2	0.35
50	60.5	52.9	3.8	76.2	0.63
65	76.3	67.9	4.2	95.3	1.12
80	89.1	80.7	4.2	114.3	1.58
90	101.6	93.2	4.2	133.4	2.11
100	114.3	105.3	4.5	152.4	2.91
125	139.8	130.8	4.5	190.5	4.49
150	165.2	155.2	5.0	228.6	7.09
200	216.3	204.7	5.8	304.8	14.40
*200	219.1	207.5	5.8	304.8	14.40
250	267.4	254.2	6.6	381.0	25.40
*250	273.0	259.8	6.6	381.0	25.40
300	318.5	304.7	6.9	457.2	38.10
*300	323.8	310.0	6.9	457.2	38.10
350	355.6	339.8	7.9	533.4	56.70
400	406.4	390.6	7.9	609.6	74.30
450	457.2	441.4	7.9	685.8	94.20
500	508.0	492.2	7.9	762.0	117.00
600	609.6	–	–	914.4	–

90° ELBOWS SHORT RADIUS

Nominal Pipe Sizemm	Outside DiameterODmm	SGP	A	Mass (kg)(approx.)90ES – SGP
Inside DiameterID	Wall ThicknessT
25	34.0	27.6	3.2	25.4	0.10
32	42.7	35.7	3.5	31.8	0.17
40	48.6	41.6	3.5	38.1	0.23
50	60.5	52.9	3.8	50.8	0.42
65	76.3	67.9	4.2	63.5	0.74
80	89.1	80.7	4.2	76.2	1.05
90	101.6	93.2	4.2	88.9	1.41
100	114.3	105.3	4.5	101.6	1.94
125	139.8	130.8	4.5	127.0	2.99
150	165.2	155.2	5.0	152.14	4.73
200	216.3	204.7	5.8	203.2	9.61
*200	219.1	207.5	5.8	203.2	9.61
250	267.4	254.2	6.6	254.0	16.90
*250	273.0	259.8	6.6	254.0	19.60
300	318.5	304.7	6.9	304.8	25.40
*300	323.8	310.0	6.9	304.8	25.40
350	355.6	339.8	7.9	355.6	37.80
400	406.4	390.6	7.9	406.4	–

45° ELBOWS LONG RADIUS

Nominal Pipe Sizemm	Outside DiameterODmm	SGP	A		Mass (kg)(approx.)45EL – SGP
Inside DiameterID	Wall ThicknessT	B
15	21.7	16.1	2.8	38.1	15.8	0.04
20	27.2	21.6	2.8	38.1	15.8	0.05
25	34.0	27.6	3.2	38.1	15.8	0.07
32	42.7	35.7	3.5	47.6	19.7	0.13
40	48.6	41.6	3.5	57.2	23.7	0.18
50	60.5	52.9	3.8	76.2	31.6	0.32
65	76.3	67.9	4.2	95.3	39.5	0.56
80	89.1	80.7	4.2	114.3	47.3	0.79
90	101.6	93.2	4.2	133.4	55.3	1.06
100	114.3	105.3	4.5	152.4	63.1	1.46
125	139.8	130.8	4.5	190.5	78.9	2.25
150	165.2	155.2	5.0	228.6	94.7	3.54
200	216.3	204.7	5.8	304.8	126.2	7.20
*200	219.1	207.5	5.8	304.8	126.2	7.20
250	267.4	254.2	6.6	381.0	157.8	12.70
*250	273.0	259.8	6.6	381.0	157.8	12.70
300	318.5	304.7	6.9	457.2	189.4	19.00
*300	323.8	310.0	6.9	457.2	189.4	19.00
350	355.6	339.8	7.9	533.4	220.9	28.40
400	406.4	390.6	7.9	609.6	252.5	37.10
450	457.2	441.4	7.9	685.8	284.1	47.10
500	508.0	492.2	7.9	762.0	315.6	58.30
600	609.6	–	–	914.4	378.7	–

WELDING REDUCERS CONCENTRIC AND ECCENTRIC

Nominal Pipe Sizemm	Outside DiameterODmm	LengthLmm	Mass(approx.)SGP – kg		Nominal Pipe Sizemm	Outside DiameterODmm	LengthLmm	Mass(approx.)SGP – kg
20 x 15	27.2 x 21.7	38.1	0.057		125 x 65	139.8 x 76.3	127.0	1.50
25 x 20	34.0 x 27.2	50.8	0.110		150 x 125	165.2 x 139.8	139.7	2.55
25 x 15	34.0 x 21.7	50.8	0.100		150 x 100	165.2 x 114.3	139.7	2.36
32 x 25	42.7 34.0	50.8	0.154		150 x 90	165.2 x 101.6	139.7	2.27
32 x 20	42.7 x 27.2	50.8	0.140		150 x 80	165.2 x 89.1	139.7	2.18
32 x 15	42.7 x 21.7	50.8	0.129		150 x 65	165.2 x 76.3	139.7	2.09
40 x 32	48.6 x 42.7	63.5	0.232		200 x 150	219.1 x 165.2	152.4	4.17
40 x 25	48.6 x 34.0	63.5	0.209		200 x 125	219.1 x 139.8	152.4	3.87
40 x 20	48.6 x 27.2	63.5	0.191		200 x 100	219.1 x 114.3	152.4	3.67
50 x 40	60.5 x 48.6	76.2	0.364		200 x 90	219.1 x 101.6	152.4	3.57
50 x 32	60.5 x 42.7	76.2	0.344		250 x 200	273.0 x 219.1	177.8	6.87
50 x 25	60.5 x 34.0	76.2	0.315		250 x 150	273.0 x 165.2	177.8	6.32
50 x 20	60.5 x 27.2	76.2	0.293		250 x 150	273.0 x 139.8	177.8	6.06
65 x 50	76.3 x 60.5	88.9	0.594		300 x 250	323.8 x 273.0	203.2	9.97
65 x 40	76.3 x 48.6	88.9	0.543		300 x 200	232.8 x 219.1	203.2	9.29
65 x 32	76.3 x 42.7	88.9	0.518		300 x 150	323.8 x 165.2	203.2	8.69
65 x 25	76.3 x 34.0	88.9	0.482		300 x 125	323.8 x 139.8	203.2	8.39
80 x 65	89.1 x 76.3	88.9	0.725		350 x 300	355.6 x 323.8	330.2	21.20
80 x 50	89.1 x 60.5	88.9	0.658		350 x 250	355.6 x 273.0	330.2	19.70
80 x 40	89.1 x 48.6	88.9	0.611		350 x 200	355.6 x 219.1	330.2	18.30
80 x 32	89.1 x 42.7	88.9	0.587		400 x 350	406.4 x 355.6	355.6	20.90
90 x 80	101.6 x 89.1	101.6	0.961		400 x 300	406.4 x 323.8	355.6	19.80
90 x 65	101.6 x 76.3	101.6	0.899		400 x 250	406.4 x 273.0	355.6	18.20
90 x 50	101.6 x 60.5	101.6	0.826		450 x 400	457.2 x 406.4	381.0	26.30
90 x 40	101.6 x 48.6	101.6	0.771		450 x 350	457.2 x 355.6	381.0	24.50
100 x 90	114.3 x 101.6	101.6	1.170		450 x 300	457.2 x 323.8	381.0	23.30
100 x 80	114.3 x 89.1	101.6	1.100		500 x 450	508.0 x 457.2	508.0	40.00
100 x 65	114.3 x 76.3	101.6	1.040		500 x 400	508.0 x 406.4	508.0	37.60
100 x 50	114.3 x 60.5	101.6	0.967		500 x 350	508.0 x 355.6	508.0	35.30
125 x 100	139.8 x 114.3	127.0	1.740		600 x 500	609.6 x 508.0	508.0	–
125 x 90	139.8 x 101.6	127.0	1.650		600 x 450	609.6 x 457.2	508.0	–
125 x 80	139.8 x 89.1	127.0	1.580

TEES EQUAL AND UNEQUAL

Nominal Pipe Sizemm	Outside DiameterODmm	SGP	A	B	Mass (kg)(approx.)
Inside DiameterID	Wall ThicknessT
15	21.7	16.1	2.8	25.4	25.4	0.085
20	27.2	21.6	2.8	28.6	28.6	0.122
25	34.0	27.6	3.2	38.1	38.1	0.236
32	42.7	35.7	3.5	47.6	47.6	0.441
40	48.6	41.6	3.5	57.2	57.2	0.573
50	60.5	52.9	3.8	63.5	63.5	0.851
65	76.3	67.9	4.2	76.2	76.2	1.42
80	89.1	80.7	4.2	85.7	85.7	1.87
90	101.6	93.2	4.2	95.3	95.3	2.37
100	114.3	105.3	4.5	104.8	104.8	3.13
125	139.8	130.8	4.5	123.8	123.8	4.53
150	165.2	155.2	5.0	142.9	142.9	6.84
200	219.1	207.5	5.8	177.8	177.8	12.80
250	273.0	259.8	6.6	215.9	215.9	21.8
300	323.8	310.0	6.9	254.0	254.0	32.0
350	355.6	339.8	7.9	279.4	279.4	44.7
400	406.4	390.6	7.9	304.8	304.8	55.2
450	457.2	441.4	7.9	342.9	342.9	70.0
500	508.0	492.2	7.9	381.0	381.0	86.6

WELDING CAPS

Nominal Pipe Sizemm	Outside DiameterODmm	SGP	E	Mass (kg)(approx.)SGP
Inside DiameterID	Wall ThicknessT
50	60.5	52.9	3.8	38.1	0.228
65	76.3	67.9	4.2	38.1	0.339
80	89.1	80.7	4.2	50.8	0.507
90	101.6	93.2	4.2	63.5	0.706
100	114.3	105.3	4.5	63.5	0.877
125	139.8	130.8	4.5	76.2	1.29
150	165.2	155.2	5.0	88.9	1.99
200	219.1	207.5	5.8	101.6	3.61
250	273.0	259.8	6.6	127.0	6.33
300	323.8	310.0	6.9	152.4	9.43
350	355.6	339.8	7.9	165.1	13.2
400	406.4	390.6	7.9	177.8	16.6
450	457.2	441.4	7.9	203.2	21.2
500	508.0	492.2	7.9	228.6	26.4