Grain Systems Tanks PNEG-4072G - Manual (Page 86)

Chapter 7: Roof Assembly
Assembling Purlin Number 3
Purlin number 3 is located third from the eave.
Before You Begin
Place two roof rafters on the ground with roof panel holes facing up. Several A-frame assemblies will have
X-bracing installed and be placed periodically throughout the perimeter of the roof. Determine if X-bracing
is being installed and note those steps in this procedure.
What You Should Know
The A-frame assembly consists of two roof rafters identified as the left-hand roof rafter (A) and the right-
hand roof rafter (C). The purlin configuration may not be the same on all A-frames at this location, (number
3), depending if X-bracing is being installed or not.
There are also four different purlin clips, an upper and lower left purlin clip (E and J) and an upper and
lower right purlin clip (D and K). The left purlin clips have seven holes, compared to the right, which have
six holes along the purlin and purlin clip mating surface.
NOTE: The seventh hole located in the center of the left purlin clips (E and J) is for identification purposes
only. No hardware is used in this location.
1. Attach an upper left purlin clip (E) and an upper right purlin clip (D) to the right-hand roof rafter (C),
and install the bottom two flange bolts (F) and two flange nuts (I).
2. Attach an upper left purlin clip (E) and an upper right purlin clip (D) to the left-hand roof rafter (A), and
install the top two flange bolts (F) and two flange nuts (I).
3. Secure the bottom portion of the previously attached X-braces (L and M) with a flange bolt (F) and
one flange nut (I) to the upper left purlin clips and the upper right purlin clips. For top portion details,
see
Assembling Purlin Number 4, page 84 .
4. Install a flange bolt (N) and a flange nut (O) securing the X-braces together where they cross.
5. Position the purlin (H) to the upper right purlin clip (D) and the upper left purlin clip (E) located
between each roof rafter.
6. Attach a lower left purlin clip (J) and a lower right purlin clip (K) to the purlin and install twelve flange
bolts (B) and twelve flange nuts (G), securing the purlin to the purlin clips.
NOTE: If no X-bracing is being installed, proceed to step 9.
7. Attach the bottom X-brace (Q) to the lower right purlin clip (K) and the right-hand roof rafter (C), and
install a flange bolt (F) and a flange nut (I) into the bottom hole.
IMPORTANT: For adjustment purposes, DO NOT tighten the X-brace flange bolts until all X-braces
have been installed.
8. Attach the top X-brace (P) to the lower left purlin clip (J) and the left-hand roof rafter (A), and install a
flange bolt (F) and one flange nut (I) into the top hole.
NOTE: The bottom portion of the X-braces will be secured to the upper purlin clips in the next purlin
assembly. The X-braces will be secured together only after the bottom portion of each X-
brace is secured. For details, see
Assembling Purlin Number 2, page 88
9. After all purlins are installed, tighten the hardware to the recommended torque specifications. See
Bolt Torque Specifications, page 24 .
86 Pneg-4072G 72 Ft Diameter 40-Series Bin