| A. |
Equipment shall
be resistant to chemical attack by compounds present in this application
and shall carry a warranty against corrosion-induced failure for eighteen
(18) months after initial start-up; not to exceed twenty-four (24)
months from date of shipment. |
| B. |
Equipment shall
be fabricated from a composite material consisting of thermoplastic
liner overlaid with fiber-reinforced plastic (FRP). The liner thickness
shall be a minimum of 3/16". Minimum thickness of the overlay
shall be 1/8"; with greater thickness as required to satisfy
structural requirements of the application. |
| C. |
Equipment
shall be fully constructed from rigid PVC or CPVC sheet. Sheet material
shall conform to ASTM D 1784-69. It shall be hot gas welded at all
seams and joints. Welds in areas subject to hydrostatic pressure
shall be tested by non-destructive spark test, and weld integrity
shall be demonstrated before application of the FRP overlay.
- Equipment
shall be fabricated in accordance with ANSI/AWS G.1.10 hot gas
thermoplastic welding standards.
- To maximize
weld strength by repeatedly maintaining proper weld root gaps
and welding rod penetrations, all thermoplastic sheet shall be
precision beveled at a 45° angle and precision cut on a CNC
router capable of maintaining a maximum allowable tolerance of
.004" at each side of all weldable joints.
- Fabrication
design shall utilize butt fusion welded longitudinal seams whenever
possible.
- Butt fusion
welding shall be performed on a CNC controlled butt fusion machine
utilizing 3 stage force control and pressure measurement.
- Butt fusion
weld quality shall be verified by microprocessor measurement and
documentation throughout the weld cycle for (3) critical parameters:
time, pressure,
and force for each of (3) production cycles: melting, heating,
and welding. Weld data to be reviewed, stamped, and certified
by a licensed professional engineer to be in accordance with ANSI/AWS
standards.
- All rectangular
scrubber sumps shall utilize formed corner construction by use
of an automatic brake capable of controlling and monitoring temperature
and pressure parameters such that no more than a 60° heated
deep-V leak proof joint is produced.
- To be assured
of consistent factory matched accuracy, all non-rectangular scrubber
components such as body flanges, pack support rings, tower gas
inlets, etc. shall be fabricated utilizing a CNC router with a
maximum allowable tolerance of .004".
|
| D. |
Prior to application
of the FRP overlay, the PVC or CPVC surface shall be prepared as
follows:
- Fill all
joints, seams, and connections with polyester paste in order to
produce a smoother surface profile.
- Remove oils
or parting agents from the surface of the PVC, and then mechanically
roughen the exterior surface.
- Apply a
graphite impregnated resin coat to all joints in the sump area
to a height of 2" above the centerline of the overflow fitting.
This material provides an electrically conductive substrate which
permits spark testing prior to and after the application of the
overlay.
|
| E. |
Fiberglass shall
be applied by hand lay-up or chopped spray techniques in accordance
with Voluntary Product Standard PSI5-69 and ASTM C582-95 for Contact
Molded Fiberglass equipment. The resin shall be general purpose polyester
such as GSL-1001-CNL, or equal. If fire retardancy is required, the
resin shall be Hetron 99P with 3% antimony trioxide or equal. A pigmented
exterior topcoat containing UV inhibitors is required. Surface hardness
shall be determined in accordance with ASTM D 2583. Random Barcol
hardness test will be taken and 80% of the readings shall exceed 90%
of the manufacturer‘s published minimum cured hardness value.
Failure to meet this test shall be considered a non-conformance and
corrections must be made by the fabricator. |
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