(11 gauge) thick; 600 mm 24 inches diameter shall be 3.5712 mm
0.1406 inch (10 gauge) thick. Header dimensions shall be as
indicated with dimensional tolerances in accordance with ASTM A
530/A 530M and ASTM A 554. Welded stainless steel fittings and
welded stainless steel tubular products shall be fabricated in
accordance with ASTM A 774/A 774M and ASTM A 778. All welding
shall be performed in the shop. Filler wire shall be added to all
welds to provide a cross section equal to the parent material.
Butt welds shall have full penetration to the interior surface.
Interior weld beads shall be smooth, evenly distributed, and with
an interior projection not exceeding 2 mm 1/16 inch. Outside weld
area shall be wire brushed with stainless steel brushes. prior to
fabrication, each part of the assembly shall be passivated by
pickling and completely neutralized. Bolts, washers, follower
flanges, and other non-welded parts shall be 304 stainless steel.
Nuts shall be low silicon bronze in accordance with ASTM B 98/B 98M.
b.
Fiberglass Systems: Piping shall be reinforced thermosetting
resin pipe in accordance with ASTM D 2310, Type I, Grade l, Class
F, ASTM D 2992, and ASTM D 2996. The pipe shall be in accordance
with the following: 65.5 MPa 9,500 psi minimum tensile strength;
110.3 MPa 16,000 psi minimum axial compression strength; minimum
55 Barcol hardness; 54.75 degree wind angle; 2.8 mm 0.110 inch
minimum wall thickness. Ultraviolet protection shall be provided
for the pipe material. The liner resin shall be 85 to 89 percent
resin with glass filler and shall be at least 0.508 mm 0.020 inch
thick. Joints shall be filled epoxy adhesive joints. Header
dimensions shall be as indicated. A 25 mm 1 inch drain leg at
each end of each section of pipe shall be provided.
2.4.4.3
Support System
A system for support and anchoring of the headers shall be provided. The
system shall be compatible with the expansion and contraction control
design. The support system shall provide for a minimum of 100 mm 4 inches
vertical adjustment and 25 mm 1 inch lateral adjustment of the header. The
system shall be contoured to fit the bottom 90 degrees of the pipe and
shall have a bearing surface at least 50 mm 2 inches wide.
2.4.5
Lagoon Air Distribution System
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NOTE: Delete inapplicable header types and
materials of construction.
**************************************************************************
2.4.5.1
Fixed Air Distribution Headers
Fixed air distribution headers shall be provided to connect the air main to
the lagoon aeration diffuser tubing. Header and feeder piping shall be PVC
with flanged or threaded connections. The air distribution system shall be
one of the following:
a.
Dual Header System: The system shall consist of a dual header
supported above the side slopes, one on each side of the lagoon
with feeder tubes connecting to each end of the diffuser tubing.
b.
Single Header System: The system shall consist of a single
header, supported above the lagoon bottom in the center of the
SECTION 11375A
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