[Code of Federal Regulations]
[Title 30, Volume 1]
[Revised as of July 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 30CFR18.6]
[Page 94-97]
TITLE 30--MINERAL RESOURCES
CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
PART 18_ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES--Table of
Contents
Subpart A_General Provisions
Sec. 18.6 Applications.
(a)(1) Investigation leading to approval, certification, extension
thereof, or acceptance of hose or conveyor belt, will be undertaken by
MSHA only pursuant to a written application. The application shall be
accompanied by all necessary drawings, specifications, descriptions, and
related materials, as set out in this part. Fees calculated in
accordance with part 5 of this title shall be submitted in accordance
with Sec. 5.40.
(2) Where the applicant for approval has used an independent testing
laboratory under part 6 of this chapter to perform, in whole or in part,
the necessary testing and evaluation for approval
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under this part, the applicant must provide to MSHA as part of the
approval application:
(i) Written evidence of the laboratory's independence and current
recognition by a laboratory accrediting organization;
(ii) Complete technical explanation of how the product complies with
each requirement in the applicable MSHA product approval requirements;
(iii) Identification of components or features of the product that
are critical to the safety of the product; and
(iv) All documentation, including drawings and specifications, as
submitted to the independent laboratory by the applicant and as required
by this part.
(3) An applicant may request testing and evaluation to non-MSHA
product safety standards which have been determined by MSHA to be
equivalent, under Sec. 6.20 of this chapter, to MSHA's product approval
requirements under this part. A listing of all equivalency
determinations will be published in 30 CFR part 6 and the applicable
approval parts. The listing will state whether MSHA accepts the non-MSHA
product safety standards in their original form, or whether MSHA will
require modifications to demonstrate equivalency. If modifications are
required, they will be provided in the listing. MSHA will notify the
public of each equivalency determination and will publish a summary of
the basis for its determination. MSHA will provide equivalency
determination reports to the public upon request to the Approval and
Certification Center. MSHA has made the following equivalency
determinations applicable to this part 18.
(i) MSHA will accept applications for explosion-proof enclosures
under part 18 designed and tested to the International Electrotechnical
Commission's (IEC) standards for Electrical Apparatus for Explosive Gas
Atmospheres, Part 0, General Requirements (IEC 60079-0, Fourth Edition,
2004-01); and Part 1, Electrical Apparatus for Explosive Gas
Atmospheres, Flameproof Enclosures ``d'' (IEC 60079-1, Fifth Edition,
2003-11) (which are hereby incorporated by reference and made a part
hereof) provided the modifications to the IEC standards specified in
Sec. 18.6(a)(3)(i)(A) through (I) are met. The Director of the Federal
Register approves this incorporation by reference in accordance with 5
U.S.C. 552(a) and 1 CFR part 51. The IEC standards may be inspected at
MSHA's Electrical Safety Division, Approval and Certification Center,
R.R. 1, Box 251, Industrial Park Road, Triadelphia, West Virginia 26059
or at the National Archives and Records Administration (NARA). For
information on the availability of this material at NARA, call 202-741-
6030, or go to: http://www.archives.gov/federal--register/code--of--
federal--regulations/ibr--locations.html. These IEC standards may be
obtained from International Electrical Commission, Central Office 3, rue
de Varemb[eacute], P.O. Box 131, CH-1211 GENEVA 20, Switzerland.
(A) Enclosures shall be made of metal and not have a compartment
exceeding ten (10) feet in length. Glass or polycarbonate materials
shall be the only materials utilized in the construction of windows and
lenses. External surfaces of enclosures shall not exceed 150 [deg]C (302
[deg]F) and internal surface temperatures of enclosures with
polycarbonate windows and lenses shall not exceed 115 [deg]C (240
[deg]F), in normal operation. Other non-metallic materials for
enclosures or parts of enclosures will be evaluated, on a case-by-case
basis, under the new technology provisions in Sec. 18.20(b) of this
part.
(B) Enclosures shall be rugged in construction and should meet
existing requirements for minimum bolt size and spacing and for minimum
wall, cover, and flange thicknesses specified in paragraph (g)(19) of
Sec. 7.304 Technical requirements. Enclosure fasteners should be
uniform in size and length, be provided at all corners, and be secured
from loosening by lockwashers or equivalent. An engineering analysis
shall be provided for enclosure designs that deviate from the existing
requirements. The analysis shall show that the proposed enclosure design
meets or exceeds the mechanical strength of a comparable enclosure
designed to 150 psig according to existing requirements, and that
flamepath clearances in excess of existing requirements will not be
produced at an internal pressure
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of 150 psig. This shall be verified by explosion testing the enclosure
at a minimum of 150 psig.
(C) Enclosures shall be designed to withstand a minimum pressure of
at least 150 psig without leakage through any welds or castings, rupture
of any part that affects explosion-proof integrity, clearances exceeding
those permitted under existing requirements along flame-arresting paths,
or permanent distortion exceeding 0.040-inch per linear foot.
(D) Flamepath clearances, including clearances between fasteners and
the holes through which they pass, shall not exceed those specified in
existing requirements. No intentional gaps in flamepaths are permitted.
(E) The minimum lengths of the flame arresting paths, based on
enclosure volume, shall conform to those specified in existing
requirements to the nearest metric equivalent value (e.g., 12.5 mm, 19
mm, and 25 mm are considered equivalent to \1/2\ inch, \3/4\ inch and 1
inch respectively for plane and cylindrical joints). The widths of any
grooves for o-rings shall be deducted in measuring the widths of flame-
arresting paths.
(F) Gaskets shall not be used to form any part of a flame-arresting
path. If o-rings are installed within a flamepath, the location of the
o-rings shall meet existing requirements.
(G) Cable entries into enclosures shall be of a type that utilizes
either flame-resistant rope packing material or sealing rings
(grommets). If plugs and mating receptacles are mounted to an enclosure
wall, they shall be of explosion-proof construction. Insulated bushings
or studs shall not be installed in the outside walls of enclosures. Lead
entrances utilizing sealing compounds and flexible or rigid metallic
conduit are not permitted.
(H) Unused lead entrances shall be closed with a metal plug that is
secured by spot welding, brazing, or equivalent.
(I) Special explosion tests are required for explosion-proof
enclosures that share leads (electric conductors) through a common wall
with another explosion-proof enclosure. These tests are required to
determine the presence of pressure piling conditions in either enclosure
when one or more of the insulating barriers, sectionalizing terminals,
or other isolating parts are sequentially removed from the common wall
between the enclosures. Enclosures that exhibit pressures during these
tests that exceed those specified in existing requirements must be
provided with a warning tag. The durable warning tag must indicate that
the insulating barriers, sectionalizing terminals, or other isolating
parts be maintained in order to insure the explosion-proof integrity for
either enclosure sharing a common wall. A warning tag is not required if
the enclosures withstand a static pressure of twice the maximum value
observed in the explosion tests.
(ii) [Reserved]
(4) The application, all related documents, and all correspondence
concerning it shall be addressed to the Approval and Certification
Center, Rural Route 1, Box 251, Industrial Park Road,
Triadelphia, WV 26059.
(b) [Reserved]
(c) Applications for acceptance of a conveyor belt as fire resistant
shall include the following information: Trade name of the conveyor
belt, thickness of covers, friction and skim coats, number of plies,
type and weight of ply material, and designation of breaker strip or
floated ply. The applicant shall provide other description or
specifications as may be subsequently required.
(d) Applications for acceptance of hose as flame resistant shall
include the following information: Trade name of hose, identification of
materials used, including compound numbers, thickness of cover,
thickness of tube, and number and weight of plies. The applicant shall
provide other description or specifications as may be subsequently
required.
(e) Drawings, drawing lists, specifications, wiring diagram, and
descriptions shall be adequate in number and detail to identify fully
the complete assembly, component parts, and subassemblies. Drawings
shall be titled, numbered, dated and shall show the latest revision.
Each drawing shall include a warning statement that changes in design
must be authorized by MSHA before they are applied to approved
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equipment. When intrinsically safe circuits are incorporated in a
machine or accessory, the wiring diagram shall include a warning
statement that any change(s) in the intrinsically safe circuitry or
components may result in an unsafe condition. The specifications shall
include an assembly drawing(s) (see Figure 1 in Appendix II) showing the
overall dimensions of the machine and the identity of each component
part which may be listed thereon or separately, as in a bill of material
(see Figure 2 in Appendix II). MSHA may accept photographs (minimum size
8 x 10\1/2\) in lieu of assembly drawing(s).
Purchased parts shall be identified by the manufacturer's name, catalog
number(s), and rating(s). In the case of standard hardware and
miscellaneous parts, such as insulating pieces, size and kind of
material shall be specified. All drawings of component parts submitted
to MSHA shall be identical to those used in the manufacture of the
parts. Dimensions of parts designed to prevent the passage of flame
shall specify allowable tolerances. A notation ``Do Not Drill Through''
or equivalent should appear on drawings with the specifications for all
``blind'' holes.
(f) MSHA reserves the right to require the applicant to furnish
supplementary drawings showing sections through complex flame-arresting
paths, such as labyrinths used in conjunction with ball or roller
bearings, and also drawings containing dimensions not indicated on other
drawings submitted to MSHA.
(g) The applicant may ship his equipment to MSHA for investigation
at the time of filing his application and payment of the required fees.
Shipping charges shall be prepaid by the applicant.
(h) For a complete investigation leading to approval or
certification the applicant shall furnish MSHA with the components
necessary for inspection and testing. Expendable components shall be
supplied by the applicant to permit continuous operation of the
equipment while being tested. If special tools are necessary to assemble
or disassemble any component for inspection or test, the applicant shall
furnish them with the equipment to be tested.
(i) For investigation of a hose or conveyor belt, the applicant
shall furnish samples as follows:
Hose--a sample having a minimum length of 2 feet;
Conveyor belt--a sample of each type 8 inches long cut across the entire
width of the belt.
(j) The applicant shall submit a sample caution statement (see
Figure 3 in Appendix II) specifying the conditions for maintaining
permissibility of the equipment.
(k) The applicant shall submit a factory-inspection form (see Figure
4 in Appendix II) used to maintain quality control at the place of
manufacture or assembly to insure that component parts are made and
assembled in strict accordance with the drawings and specifications
covering a design submitted to MSHA for approval or certification.
(l) MSHA will accept an application for an approval, a letter of
certification, or an acceptance for listing of a product that is
manufactured in a country other than the United States provided: (1) All
correspondence, specifications, lettering on drawings (metric-system
dimensions acceptable), instructions, and related information are in
English; and (2) all other requirements of this part are met the same as
for a domestic applicant.
[33 FR 4660, Mar. 19, 1968, as amended at 43 FR 12314, Mar. 24, 1978; 47
FR 14696, Apr. 6, 1982; 57 FR 61223, Dec. 23, 1992; 60 FR 33723, June
29, 1995; 60 FR 35693, July 11, 1995; 68 FR 36419, June 17, 2003; 70 FR
46343, Aug. 9, 2005; 71 FR 28584, May 17, 2006]