Pipe Size (Nom.) | Sch. 40 PipeWater-Filled(a) | Conduit GRC(b) | Pipe Size (Nom.) | Sch. 40 PipeWater-Filled(a) | Conduit GRC(b) | |||||
Single Pier | Trapeze(d) | Single Pier | Trapeze(d) | Single Pier | Trapeze(d) | Single Pier | Trapeze(d) | |||
3/8″ | 7′ | 7′ | N/A | N/A | 21/2″ | 11′ | 11′ | 16′ | 16′ | |
1/2″ | 7′ | 7′ | 10′ | 10′ | 3″ | 12′ | 12′ | 13(‘c) | 20′ | |
3/4″ | 7′ | 7′ | 10′ | 10′ | 31/2″ | 13′ | 13′ | 11′(c) | 20′ | |
1″ | 7′ | 7′ | 12′ | 12′ | 4″ | 12′(c) | 14′ | 9′(c) | 20′ | |
11/4″ | 7′ | 7′ | 14′ | 14′ | 5″ | 8′(c) | 16′ | 6′(c) | 20′ | |
11/2″ | 9′ | 9′ | 14′ | 14′ | 6″ | 6′(c) | 17′ | 4′(c) | 20′ | |
2″ | 10′ | 10′ | 16′ | 16′ | 8″ | 4′(c) | 19′ | N/A | N/A |
Note:
(a) Based on ANSI/MSS SP-69, 2003 Edition, Table 3.
(b) Based on 2002 NEC, Table 344.30(B)(2).
(c) Spacing limited to roof base allowed load of 200 lbs. (5 psi on roof).
(d) Spacing may be limited by maximum allowed weight on trapeze to 400 lbs.