semi合集-English.pdf - 第348页
SEMI E49.7-0304 © SEMI 1995, 2004 7 closing the fitting. Manu facturer recommendations for torque sho u ld be appl ied. 10.5.4 For tapered thread ed connections, such as National Pipe Thread (NPT) and Japanese In dustria…
SEMI E49.7-0304 © SEMI 1995, 2004 6
clean, unused, cleanroom approved, cloth soaked in
ultrapure water and wrapped around a plug of a
diameter less than the ID of the pipe to be cleaned. The
length of the pig should be about 2× its diameter.
10.3.1.2 Components or assemblies that have become
contaminated should be cleaned. The procedure for
cleaning cannot be defined but frequently includes:
• Rinse in ultrapure water.
• Soak in cleaning solution if necessary and
compatible with process
• Rinse in flowing ultrapure water (see Section 7.2).
• After rinse, check cleanliness.
• If necessary, repeat the procedure until clean.
10.3.1.3 Any assemblies that have been wetted in a
cleaning process shall be dried with Nitrogen.
10.3.2 Use 2-Propanol/IPA to remove any ink
markings from the exterior of the pipe.
10.4 Welded Connections
NOTE 7: Refer to Sections 8.3 and 8.3.2 for general joining
and weld recommendations.
10.4.1 Welder Qualification
10.4.1.1 Welders should have prior experience in the
specific welding method of specific types of polymer
components. To be qualified, the welder should be able
to safely cut, prep, clean, purge, fit, and weld the sizes
for which he or she is seeking qualification and produce
consistently acceptable weld joints. It is recommended
that welders undergo weld training and certification by
a pipe manufacturer.
10.4.2 Weld Qualification
10.4.2.1 During fabrication, each welder should submit
weld samples daily to the QA manager at the beginning
of the shift. The welds should be representative of the
types of welds the welder will perform during the shift.
10.4.2.2 These welds should meet a defined criteria of
acceptability, which may include inspection for visible
discoloration, uniformity of weld area, maximum weld
misalignment, and weld bead height. These criteria
may be derived from sources such as the component
manufacturer, the process equipment manufacturer, and
the end user. General recommendations for weld
inspection are included in Section 10.4.4.
10.4.3 Welding Procedures
10.4.3.1 In general the use of weld methods that
minimize dead space and entrapment areas are the
preferred means of welding plastic pipe/tubing (i.e.,
PVDF, PFA, and Polypropylene). The weld method
should be as shown on the fabrication drawings.
NOTE 8: Users of this guideline are cautioned that suitable
welding methods, such as thermal butt welding, may be
covered by patents or other intellectual property. When
possible, use reduced bead welding method and fixturing to
reduce areas on inside diameter where bacteria may
accumulate.
10.4.3.2 Welding equipment should be maintained in
accordance with manufacturer recommendations. For
example, tools and heating elements should be kept
clean and thermostat should be calibrated regularly.
10.4.3.3 Components should be firmly and accurately
clamped in the welding equipment. Check alignment
and clamp adjustment regularly.
10.4.3.4 Logs should be kept for each weld to ensure
traceability back to the welding equipment, welder, date
of weld, and inspector.
10.4.4 Weld Inspection Criteria
NOTE 9: Refer to manufacturer recommendations for socket
weld inspection criteria.
10.4.4.1 All welds should exhibit little or no visible
discoloration.
10.4.4.2 The maximum weld misalignment should be
10% of the wall thickness of the material.
10.4.4.3 Visual inspection for voids should be
performed in accordance with manufacturers
recommendations.
10.4.4.4 The physical characteristics of the weld bead
should be in accordance with criteria which may be
derived from component manufacturer, process
equipment manufacturer, and end user
recommendations.
10.5 Mechanical Connections
NOTE 10: Joining technology that is free of dead space and
entrapment areas is recommended. See Sections 8.3 and 8.3.1
for general joining recommendations and specific mechanical
connection recommendations. In the event that these
recommendations cannot be followed, assembly
recommendations for other commonly used mechanical
connections are provided.
10.5.1 Flaring should be performed at the temperature
and with the equipment recommended by the fitting
manufacturer.
10.5.2 O-rings used in mechanical connections should
be positioned per manufacturer recommendations
before closing the fitting. Manufacturer
recommendations for torque should be applied.
10.5.3 Gaskets used in flanged connections should be
positioned per manufacturer recommendations before
SEMI E49.7-0304 © SEMI 1995, 2004 7
closing the fitting. Manufacturer recommendations for
torque should be applied.
10.5.4 For tapered threaded connections, such as
National Pipe Thread (NPT) and Japanese Industrial
Standard (JIS), wrap tapered threads with a suitable
tape, (such as PTFE tape) prior to assembly. Use of ¼”
wide tape is recommended on nominal sizes of ½” or
smaller. Wrap the threads three times in the direction
that does not unravel during installation of the fitting.
To reduce the possibility of tape entering the liquid
stream, do not cover the last two threads at the narrow
end of the fitting.
10.6 Tubing and Pipe Support
10.6.1 Route flexible tubing neatly and secure with tie-
wraps or similar mechanical fastener.
10.6.2 Support distances and support clamps for pipe
should employ the manufacturer’s recommendations,
where possible. These clamps typically cradle the pipe
within a plastic fixture. Metal and/or constrictive types
of clamps may induce stress into piping components
and should be avoided. However, if they must be used
then elastomer inserts between the pipe and clamp are
recommended.
10.7 Labeling Recommendations
10.7.1 All ultrapure water and Liquid Chemical
systems should be labeled in accordance with SEMI
F34 when possible.
10.7.2 Additional labeling to support proper operation
of the system(s) should be included when indicated on
assembly drawing(s).
10.8 Final Assembly Inspection Recommendations
10.8.1 Inspect the system within the appropriate
assembly environment.
10.8.2 Verify the following:
• System is complete per drawings
• Critical dimensions, squareness, offsets, and
straightness are per drawings and assembly
specifications
• Overall configuration is correct
• Support is adequate
• No pipe, tube, or fitting is nicked, cracked, or
abused
• Each weld is visually acceptable
• Gaskets are in place and bolts are torqued to proper
values
• Proper installation of valves per manufacturer’s
recommendations
• Unions and mechanical connections are tight
• Tubing, pipe, inlets, and outlets are labeled
appropriately
10.8.3 Shop drawings that have been marked up should
be returned to the engineering department for updates.
The QA manager should be notified that the assembly
has passed inspection, been tagged as such, and is ready
for final testing.
11 System Testing Recommendations
11.1 The equipment manufacturer should successfully
complete functional testing (for example leak and
pressure decay testing). In addition, testing may be
required to demonstrate that the system is not adversely
affecting the quality of the liquid.
11.2 Any assemblies that have been wetted during
testing shall be dried with Nitrogen.
NOTE 11: As outlined in limitations Section 3.1, it is beyond
the scope of this document to define the performance
requirements of the equipment systems.
12 Packaging Recommendations
12.1 Packaging is recommended to ensure the
cleanliness and dryness of wetted surfaces during
transport or storage. All open connections should be
capped to isolate wetted materials from contamination.
Additional guidelines for packaging can be found in
other SEMI documents. For smaller assemblies refer to
the requirements found in SEMI F57. For larger
assemblies refer to the requirements found in SEMI
E49.1.
13 Traceability Recommendations
13.1 A completed assembly should have permanent
identification such that it is traceable to the
documentation recommended within this guide. The
manufacturer is responsible for maintaining records that
include but are not limited to the following:
• Test methods and results
• Final assembly inspection
• Assembly drawing modifications
• Weld logs
SEMI E49.7-0304 © SEMI 1995, 2004 8
NOTICE: SEMI makes no warranties or
representations as to the suitability of the standards set
forth herein for any particular application. The
determination of the suitability of the standard is solely
the responsibility of the user. Users are cautioned to
refer to manufacturer' s instructions, product labels,
product data sheets, and other relevant literature,
respecting any materials or equipment mentioned
herein. These standards are subject to change without
notice.
By publication of this standard, Semiconductor
Equipment and Materials International (SEMI) takes no
position respecting the validity of any patent rights or
copyrights asserted in connection with any items
mentioned in this standard. Users of this standard are
expressly advised that determination of any such patent
rights or copyrights, and the risk of infringement of
such rights are entirely their own responsibility.