true. This alignment shall be preserved during the welding
operation. Tack welds shall be of the same quality and made by
the same procedure as the completed weld; otherwise, tack welds
shall be removed during the final welding operation.
c.
Erection: Where the temperature of the component parts being
welded reaches 0 degrees C 32 degrees F or lower, the material
shall be heated to approximately 38 degrees C 100 degrees F for a
distance of 900 mm 3 feet on each side of the weld before welding,
and the weld shall be finished before the materials cool to 0
degrees C 32 degrees F.
d.
Defective Welding: Defective welds shall be removed and replaced.
Repairing of defective welds shall be in accordance with ASME
B31.1.
e.
Electrodes: After filler metal has been removed from its original
package, it shall be protected or stored so that its
characteristics or welding properties are not affected.
Electrodes that have been wetted or that have lost any of their
coating shall not be used.
3.4.2.3
Flanges and Unions
Flanges and unions shall be faced true and made square and tight. Gaskets
shall be nonasbestos compressed material in accordance with ASME B16.21,
1.6 mm 1/16 inch thickness, full face or self-centering flat ring type.
The gaskets shall contain aramid fibers bonded with styrene butadiene
rubber (SBR) or nitrile butadiene rubber (NBR). NBR binder shall be used
for hydrocarbon service. Union or flange joints shall be provided in each
line immediately preceding the connection to each piece of equipment or
material requiring maintenance, such as coils, pumps, control valves, and
other similar items.
3.4.3
Supports
3.4.3.1
General
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NOTE: Mechanical and electrical layout drawings and
specifications for ceiling suspensions should
contain notes indicating that hanger loads between
panel points in excess of 23 kg (50 pounds) shall
have the excess hanger loads suspended from panel
points.
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Hangers used to support piping 50 mm 2 inches and larger shall be
fabricated to permit adequate adjustment after erection while still
supporting the load. Pipe guides and anchors shall be installed to keep
pipes in accurate alignment, to direct the expansion movement, and to
prevent buckling, swaying, and undue strain. All piping subjected to
vertical movement when operating temperatures exceed ambient temperatures,
shall be supported by variable spring hangers and supports or by constant
support hangers. [Pipe hanger loads suspended from steel joist between
panel points shall not exceed 23 kg 50 pounds. Loads exceeding 23 kg 50
pounds shall be suspended from panel points.]
SECTION 15559A
Page 101
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