MIL-DTL-52618/4E
The size of the largest run opening shall be given first, followed by the size of the opening at the
opposite end of the run. The size of the side outlet or branch is given last; see figure 2, and examples:
4x3x2 Tee
1x1x1-1/2 Tee
FIGURE 2. Run and branch.
Size code number designators shall be in accordance with table I.
TABLE I. Size code number for reducing tees.
Nominal pipe size
(inch) x (inch) x (branch inch)
Size code
number
Port
Port
Port
1
2
3
405
1/2
x
1/2
x
3/8
406
1/2
x
1/2
x
1/4
410
3/4
x
3/4
x
1/2
411
3/4
x
3/4
x
3/8
412
3/4
x
3/4
x
1/4
413
3/4
x
1/2
x
3/4
414
3/4
x
1/2
x
1/2
415
1/2
x
1/2
x
3/4
416
1
x
1
x
3/4
417
1
x
1
x
1/2
418
1
x
1
x
3/8
419
1
x
3/4
x
1
420
1
x
3/4
x
3/4
421
1
x
3/4
x
1/2
422
1
x
1/2
x
1
423
1
x
1/2
x
3/4
424
1
x
1/2
x
1/2
425
1
x
3/8
x
1
2