Length & Spacing Welded Nozzles

Minimum Length and Spacing without Reninforcement

NPS of Nozzle	Center of Nozzle to End of Run A	O.D. of Run to End of Nozzle B	O.D. to O.D. of Nozzle C
2.1/2	114	76	76
3	127	89	89
4	152	102	102
5	178	114	114
6	203	127	127
8	254	152	152
10	305	178	178
12	356	203	203
14	381	216	216
16	432	229	229
18	483	254	254
20	533	279	279
24	610	305	305
	Table 1 - 3

Minimum Length and Spacing with Reninforcement

NPS of Nozzle	Center of Nozzle to End of Run A	O.D. of Run to End of Nozzle B	O.D. to O.D. of Nozzle C
2.1/2	152	114	152
3	178	127	178
4	203	140	203
5	241	152	241
6	279	165	279
8	356	203	356
10	432	241	432
12	508	279	508
14	559	305	559
16	635	330	635
18	711	356	711
20	787	381	787
24	914	406	914
	Table 2 - 3

Minimum Length and Spacing Integrally Reinforced

NPS of Nozzle	Center of Nozzle to End of Run A	O.D. of Run to End of Nozzle B	O.D. to O.D. of Nozzle C
2.1/2	140	MFR Standard	76
3	152		76
4	178		89
5	203		102
6	254		127
8	305		152
10	356		178
12	406		216
14	432		229
16	483		254
18	533		279
20	584		305
24	660		356
	Table 3 - 3

Notes..

MFR = Manufacturer
All nozzle welds should be checked for compliance with the applicable code requirements.
It is preferred that multiple branch openings of in-line nozzles be spaced so that their reinforcement zones do not overlap. If closer specing is necessary, the reinforcement requirements of the applicable construction code shall be met.
Some configurations of integrally reinforced nozzles in combination with certain header sizes may present a problem in the radiographic examination of the attachment weld due to inability to meet the geometric unsharpness requirements of the construction code.
Where attachments such as flanges, fittings valve and pipe insulation are involved, minimum dimensions tabulated may have to be increased to allow for required clearances.
In special cases, it may be possible to reduce the dimensions given in the tables. Such design should then be submitted to the fabricator for individual considerations, as close spacing may involve additional shop operation to prevent, or correct distortion.
Integrally reinforced nozzles are considered to be the commercially available types.
In cases of different nozzle diameters, dimension C, should be determinded on the basis of the larger of the two of adjacted nozzles.

Certain materials and combinations of nozzle and header pipe size and wall thickness together with multiple branch openings welded to a header may result in distortion of the header pipe.