Rubber Silicone, High Strength, Cabin Pressure Seal Material, Diaphragm Type
NOTICE
This document has been taken
directly from U.S. Military Specification
MIL-R-83283A and contains only minor editorial and
format changes required to bring it into conformance
with the publishing requirements
of SAE technical standards. The initial release of
this document is intended to replace
MIL-R-83283A. Any part numbers established by the
original specification remain unchanged.
The original Military Specification was adopted as
an SAE standard under the provisions of the SAE
Technical Standards Board (TSB) Rules and
Regulations (TSB 001) pertaining to accelerated
adoption of government specifications and standards.
TSB rules provide for (a) the publication of
portions of
unrevised government specifications and standards
without consensus voting at the SAE Committee level,
and (b) the use of the existing government
specification or standard format.
Any material relating to qualified product lists has
not been adopted by SAE. This material was part of
the original military specification and is reprinted
here for historic reference only.
1. SCOPE:
1.1 Scope:
This specification covers 45 durometer hardness,
high strength silicone rubber.
2. APPLICABLE DOCUMENTS:
The following publications, of the issues in effect
on date of invitation for bids or request for
proposal, form a part of this specification to the
extent specified herein.
2.1 U.S. Government Publications:
Available from DODSSP, Subscription Services Desk,
Building 4D, 700 Robbins Avenue, Philadelphia, PA
19111-5094.
MIL-STD-105 Sampling Procedures and Tables for
Inspection by Attributes
MIL-STD-129 Marking for Shipment and Storage
MIL-STD-407 Visual Inspection Guide for Rubber
Molded Items
PPP-B--601 Boxes, Wood, Cleated-Plywood
PPP-B-636 Box, Shipping, Fiberboard
2.2 ASTM Publications:
Available from ASTM, 100 Barr Harbor Drive, West
Conshohocken, PA 19428-2959. ASTM D 297 Rubber
Products - Chemical Analysis
ASTM D 395 Rubber Property - Compression Set
ASTM D 412 Vulcanized Rubber and Thermoplastic
Rubbers and Thermoplastic Elastomers- Tension
ASTM D 573 Rubber-Deterioration in an Air Oven
ASTM D 624 Tear Strength of Conventional Vulcanized
Rubber and Thermoplastic Elastomers
ASTM D 813 Rubber Deterioration - Crack Growth
ASTM D 1329 Evaluating Rubber Property - Retraction
of Lower-Temperatures (TR Test) ASTM D 2240 Rubber
Property - Durometer Hardness
ASTM D 2632 Rubber Property - Resilience by Vertical
Rebound
2.3 Uniform Classification Committee, Agent:
Available from the Uniform Classification Committee,
Room 1106, 222 South Riverside Plaza, Chicago, IL
60606.
Uniform Freight Classification Rules
3. REQUIREMENTS:
3.1 First article:
When specified (see 6.2) the silicone rubber
furnished to this specification shall be a product
subject
to first article inspections in accordance with 4.4.
The approval of the first article sample authorizes
the commencement of production, but does not relieve
the supplier of responsibility for compliance with
all applicable provisions of this specification. The
first article sample shall be manufactured in
the same facilities to be used for the manufacture
of the production items.
3.2 Materials:
The material shall be a silicone base synthetic
elastomer formulated and processed to meet the
requirements of this specification. All materials
which are not specifically described herein shall be
of high quality and suitable for the intended
purpose and shall be of the same composition as the
material used for the first article sample. The
silicone rubber shall not deteriorate finished
surfaces
of wood, metal, or fabric which it contacts during
normal usage. Unless otherwise specified, vulcanized
joints shall be of the same size as the remaining
part and shall possess at least 65 percent of the
tensile strength of the parent material.
3.3 Dimensions and tolerances:
Dimensions and tolerances of the silicone rubber
shall be as specified on the applicable drawing as
supplied by the procuring activity (see 6.2).
3.4 Physical properties:
The physical properties of the silicone rubber shall
conform to the requirements specified in table I.
3.5 Workmanship:
The product shall be free from defects, and foreign
materials and shall be uniform in quality; also it
shall be smooth and free from flash unless otherwise
specified on the drawing or contract.
4. QUALITY ASSURANCE PROVISIONS:
4.1 Responsibility for inspection:
Unless otherwise specified in the contract or
purchase order, the contractor is responsible for
the performance of all inspection requirements
(examinations and tests) as specified herein. Except
as otherwise specified in the contract or purchase
order, the contractor may use their own or any other
facilities suitable for the performance of the
inspection requirements specified herein, unless
disapproved by the Government. The Government
reserves the right to perform any of the
inspections set forth in the specification where
such inspections are deemed necessary to assure
supplies and services conform to prescribed
requirements.
4.1.1 Responsibility for compliance: All items shall
meet all the applicable requirements of section 3
and
5. They shall meet all inspections set forth in the
inspection system or quality program. The absence of
any inspection requirements in this specification
shall not relieve the contractor of the
responsibility of ensuring that all products or
supplies submitted to the Government for acceptance
comply with all requirements of the contract.
Sampling inspections as part of manufacturing
operations, is an acceptable practice to ascertain
conformance to requirements, however this does not
authorize submission of known defective material,
either indicated or actual, nor does it commit the
Government to acceptance of defective material.
1/ Value determined during first article testing.
The quality conformance test values shall not
deviate from the original first article values by
more than ?.02.
4.2 Classification of inspections:
The inspection requirements specified herein are
classified as follows:
a. First article inspection (see 4.4)
b. Quality conformance inspection (4.5)
4.3 Inspection conditions:
Unless otherwise specified, all inspections shall be
performed in accordance with the test conditions
specified in section 4.
4.3.1 Test condition: Unless otherwise specified
herein, all test specimens shall be conditioned and
tested at normal laboratory conditions or in
accordance with table III. In case of dispute over
test results, the tests shall be repeated using
standard conditions in accordance with 4.3.2.
4.3.2 Standard conditions: Standard conditions shall
be 50 ?15 percent relative humidity and at a
temperature of 75°F ?5°F.
4.3.4 Lot: A lot shall consist of
all material of the same identity cured in the same
production run, from
the same batch, and submitted at the same time for
inspection.
4.3.5 Batch: A batch shall be the quantity of
material compounded on a mill or mixer at one time.
4.4 First article inspection:
First article inspection shall consist of all the
tests specified herein (see 4.6).
4.4.1 First article samples: First article test
samples shall be obtained from 6 by 6 by 0.075 ?
0.005 inch molded sheets.
4.4.2 First article tests: The first article tests
shall meet all the requirements in 3.4 when tested
in accordance with 4.6.
4.5 Quality conformance inspection:
Quality conformance inspection shall consist of
sampling plans, A, B, C and D.
4.5.1 Sampling: Unless otherwise indicated herein,
sampling for quality conformance inspection shall be
in accordance with MIL-STD-105. Quality conformance
tests are required on final parts for all production
lots of material.
4.5.2 Inspection of materials and components: The
supplier is responsible for insuring that materials
and components used where manufactured, tested, and
inspected in accordance with referenced subsidiary
specifications and standards to the extend
specified, or if none, in accordance with this
specification (see 4.1). In the event of conflict,
this specification shall govern.
4.5.3 Sampling plan A: Whenever possible, the end
item, or specimens cut from the end item, shall be
used as the sample. If these items are unsuitable
for use as test samples, such as being fabric
reinforced, test shall be performed on 6 by 6 by
0.075 ?0.005 inch samples of identical
composition and comparable state of cure as that of
the end item. The samples shall be subjected
to the following tests that are conducted on each
lot of material:
Original (Table III)
Air aged (4.6.3)
Tensile strength
Tensile strength
Elongation
Elongation
Hardness
Hardness
Tear strength
Compression set
Tension set
Specific gravity
4.5.3.1 Rejection criteria: A lot shall be rejected
upon the failure of the samples to meet the test
requirements specified herein. A lot that has been
rejected may be reworked to correct the deficiencies
and resubmitted for acceptance.
4.5.4 Sampling plans B, C, and D:
Examination of the end item shall be in accordance
with the
classification of defects, inspection levels, and
acceptance quality levels (AQL’s) set forth herein.
The lot size, for the purpose of determining the
sample size in accordance with MIL-STD-105, shall
be expressed in units of finished parts, for
examinations as specified herein (see 4.5.4.1,
4.5.4.2, and 4.5.4.3).
4.5.4.1 Sampling plan B - Examination for defects in
appearance and workmanship: The sample unit shall be
one finished part and the examination shall be in
accordance with MIL-STD-407. The
sample size shall be in accordance with MIL-STD-105,
inspection level II, and the AQL related to percent
(%) defective shall be 1.5.
4.5.4.2 Sampling plan C - examination for
dimensional defects: The sample unit shall be one
finished part. The dimensions shall be within the
tolerances specified on the drawing as supplied by
the procuring activity (see 6.2). The sample size
shall be in accordance with inspection level II of
MIL-STD-105 and the AQL related to percent defective
shall be 1.5.
4.5.4.3 Sampling plan D - inspection for defects in
packaging for delivery: An examination in
accordance with table II shall be made to determine
that the packaging, packing, and markings comply
with section 5 and are in accordance with the
applicable methods specified in table II.
The sample unit for this inspection shall be one
shipping container fully packed, selected just
prior to the closing operation. Shipping containers
fully prepared for delivery shall be inspected for
closure defects.
4.6 Inspection test methods:
4.6.1 Physical properties test: Conformance with the
physical properties shall be determined in
accordance with the applicable test methods
specified in table III.
1/ The test specimen shall be held
for 10 minutes at 300 percent elongation and be
allowed 5
minutes for recovery prior to the tension set
measurement.
4.6.2 Compression set test: Compression set shall be
determined in accordance with ASTM D 395, method B,
except that the aging time and temperature shall be
in accordance with table I. Test specimens shall be
plied up to obtain required thickness.
4.6.3 Air aging: Air aging shall be conducted in
accordance with ASTM D 573, except that the aging
time and temperature shall be in accordance with
table I. Tensile strength, elongation, and hardness
changes shall be determined as specified (see
4.6.1).
4.6.3.1 Bend, flat test: Bend flat test shall be
conducted by bending a sample 180 degrees flat upon
itself, after being exposed to the air aging as
specified (see table I).
5. PACKAGING:
5.1 Preservation:
Preservation shall be level A or C, as specified
(see 6.2).
5.1.1 Level A:
5.1.1.1 Finished parts: Finished rubber parts shall
be packaged in containers conforming to PPP-B-636.
The unit quantity shall be as specified by the
procuring specification activity (see 6.2).
5.1.2 Level C: The silicone rubber
shall be preserved and packaged to protect against
deterioration and
physical damage during shipment. This level may
conform to the supplier’s commercial practice when
the practice meets the requirements of this level.
5.2 Packing:
Packing shall be level A, B, C, as specified (see
6.2).
5.2.1 Level A: Unless otherwise specified by the
procuring activity, rubber material shall be packed
in wood, cleated-plywood shipping containers
conforming to PPP-B-601, overseas type. As far as
practical, containers shall be uniform in shape and
size and contain identical quantities. Container
closure and strapping shall be in accordance with
the appendix to PPP-B-601. Gross weight of
containers shall not exceed 200 pounds.
5.2.2 Level B: Level B shall be the same as level A
except containers shall conform to domestic type and
gross weight shall not exceed 500 pounds.
5.2.3 Level C: Packages which require overpacking
for acceptance by the carrier shall be packed in
exterior-type shipping containers in a manner that
will insure transportation at the lowest rate to the
point of delivery. Containers shall conform to the
Uniform Freight Classification Rules or
regulations of other common carrier, as applicable
to the mode of transportation. This level may
conform to the supplier’s commercial practice when
the practice meets the requirements of this level.
5.3 Marking:
5.3.1 Level A, B, C: In addition to any special
marking or other identification markings required by
the contract (see 6.2), each unit pack and exterior
container shall be marked in accordance with
MIL-STD-129 and as follows:
Rubber (silicone, cabin pressure seal, diaphragm
type) Cross section and length (inches) or part
number Manufacturer’s name and address
Compound number, lot number Specification
MIL-R-83283A(USAF) Cure date (quarter and year)
STORE IN A COOL DRY PLACE
6. NOTES:
(This section contains information of a general
explanatory nature that may be helpful, but is not
mandatory.)
6.1 Intended use:
The rubber covered by this specification is intended
for use as a diaphragm type, cabin pressure scal.
6.2 Acquisition document:
Acquisition documents should specify the following:
a. Title, number, and date of this specification. b.
Dimensions and tolerances (see 3.3)
c. Quantity
d. Detail drawing and additional specification, if
any.
e. Unit quantity of molded parts if other than
specified.
f. Whether first article sample is required (see
3.1).
g. Applicable levels of preservation and packing
(see 5.1 and 5.2).
6.3 First article:
When first article inspection is required for the
silicone rubber material furnished to this
specification.
A copy of the first article test report shall be
furnished the Air Force Research Laboratory, ATTN:
AFRL/MLSE, Wright Patterson Air Force Base, OH
45433-7718. The first article test need not be
repeated for new orders provided the materials and
processes have not been changed and a
certified statement to this effect is furnished to
the procuring activity. The waiving of the first
article
tests will be strictly at the discretion of the
procuring activity. First article tests will not be
acceptable
if they are more than 3 years old.
6.4 Subject term (key word) listing: Elongation
Molded parts
Temperature retraction (TR-10) Tensile strength
Science Lab ?2004 |