S9407-AB-HBK-010 Datasheet, PDF (217/276 Pages) Glenair, Inc. – HANDBOOK OF SHIPBOARD ELECTROMAGNETIC SHIELDING PRACTICES

S9407-AB-HBK-010, Rev. 2
3. REQUIREMENTS
3.1
Classification of requirements. The requirements for the conduit are classified herein as
follows:
Requirement
Paragraph
Qualification ......................................................................... 3.2
Quality conformance ............................................................ 3.3
Design and construction ...................................................... 3.4
Materials............................................................................... 3.5
Physical characteristics........................................................ 3.6
Performance characteristics ................................................ 3.7
Interchangeability................................................................. 3.8
Marking ................................................................................ 3.9
Manufacturer’s technical data .............................................. 3.10
Workmanship ....................................................................... 3.11
3.2 Qualification. Flexible metal conduit furnished under this specification shall be products which
are qualified for listing on the applicable qualified products list at the time set for opening of bids (see
4.4 and 6.3).
3.3 Quality conformance. The contractor shall test an initial production sample from each
production lot for conformance with specification requirements prior to regular production on a
contract (see 4.5).
3.4 Design and construction. Type 1 conduit (figure 1a) shall consist of metal tubing covered with
a wire overbraid. The tubing material shall be an alloy having high magnetic permeability for
electromagnetic shielding requirements and shall be corrosion resistant for environmental
requirements. Construction of the tubing shall be in the form of helical or annular convolutes for
flexibility. Seams in the tubing shall be hermetically sealed for water-tightness and shielding integrity.
The outer braid covering shall be of steel wire for mechanical protection of the tubing. Type 2 conduit
(figure 1b) shall consist of Type 1 conduit which is covered with a jacket of synthetic rubber for
electrical insulation and marked on the outside with identification information.
3.5 Materials. Materials shall conform to applicable standards and be as specified herein.
Materials which are not covered by specifications or which are not specifically described herein shall
be of the best quality and shall be suitable for the purpose intended.
3.5.1 Tubing material. Material for the tubing and the coupling ring used for joining lengths of
tubing shall be an alloy having high magnetic permeability and corrosion-resistant properties, such as
provided by Alloy Type 4 of ANSI/ASTM-A-753. Typical trade names for this alloy include: Hipernom,
HyMu “80”, and Moly Permalloy.
3.5.2 Annealing of tubing material. All conduit tubing shall be annealed in accordance with
standard practice in order to develop magnetic shielding properties necessary to meet the shielding
effectiveness requirements of 3.7.3.
Reprinted without change
D-3