Grain Systems Tanks PNEG-4072G - Manual (Page 79)

Chapter 7: Roof Assembly
Attachment Locations of Purlins to Rafters
Purlins are horizontal members between the rafters that give support to the roof structure. The length of
the purlin determines its location on the A-frame assembly.
The following reference depicts a completely assembled A-frame roof rafter section with X-bracing
installed. For more information, see the following sections:
Assembling Purlin Number 1, page 90 , Assem-
bling Purlin Number 2, page 88 , Assembling Purlin Number 3, page 86 , Assembling Purlin Number 4,
page 84 , Assembling Purlin Number 5, page 81 , and Assembling Purlin Number 6, page 80 .
Figure 7-9 Location of purlins for a 75 ft (22.86 m) diameter bin
A Location of purlin number 1 (CTR-0616) D Location of purlin number 4 (CTR-0619)
B Location of purlin number 2 (CTR-0617) E Location of purlin number 5 (CTR-0620)
C Location of purlin number 3 (CTR-0618) F Location of purlin number 6 (CTR-0621)
Pneg-4072G 72 Ft Diameter 40-Series Bin 79