Our quality control process utilizes a documented inspection system for identifying defects and out of tolerance conditions. Each o-ring is inspected and passed based on the criteria set forth in our system. Our quality control inspectors are rigorously trained to adhere to this documented system. All inspection equipment is calibrated to meet industry standards.

1. Purpose:

1.1 To assure procurement of O-rings with surface quality, dimensional tolerances
and mechanical properties that are adequate for their intended use.
1.2 To illustrate Teflon encapsulated o-ring surface imperfections with
photographs and supplementary definitions and dimensions for the purpose
of inspection and determination of acceptability.
1.3 To establish quantitative levels of acceptance for O-rings relative to
surface imperfection type, size, and quantity.

2. Scope:

2.1 The guide describes the surface condition of O-rings.
2.2 Rigorous adherence by the inspector to imperfection sizes given is not
intended. It is expected that inspectors at both the supplier and user
organizations will be able to determine a defect with the aid of 5 diopter
magnification or actual measurement.
2.3 For purpose of visual determination it is recommended that inspectors
have on hand for occasional reference, a wire gauge set starting at .003
inches. Such gauges may be positioned adjacent to imperfections for size
determination and review by comparison.

3. Sampling Plans:

3.1 Acceptance or rejection of shipments shall be determined by individual
quality sampling per Level 1 or per Level 2 at time of purchase order
date. Other quality levels can be agreed upon between supplier and user.

4. Use of Guide:

4.1 O-rings should be inspected under the conditions of section 2. Scope
2.2 and 2.3. An imperfection is acceptable if no larger than the
dimensions given for each type of imperfection. See 1. Surface
Imperfections Control I or 2. Surface Imperfections Control II.
4.2 O-rings shall be inspected and visually examined with a minimum of 400
foot-candles of illumination. 5 Diopter magnification shall normally be used for
inspection.

5. Enumeration and Classification of Imperfections:

5.1 This guide classifies only the most common surface imperfections that
occur during the fabrication of Teflon encapsulated O-rings.
5.2 In the interest of clarity, enlarged photographs of typical surface
conditions have been used.

 

1.Surface Imperfections Control I

Level I-Standard Chemical Seals

1.1 Photograph 1:
Separation in vulcanized elastomer core join area. Permissible gap of up
to 5% of O-ring cross section, only if area is filled with bonding agent.

1.2 Photograph 2:
Visible stress crack or pinholes in encapsulation. No permissible
tolerances. Automatic part reject.

1.3 Photograph 3:
Foreign particles (dirt,metal flakes,hair,etc.) on elastomer core material. Permissible particle size of up to 5% of O-ring cross section. 10 allowable particles per o-ring.

1.4 Photograph 4:
Blooming. No permissible tolerances. Automatic part reject.

1.5 Photograph 5:
Carbon deposit imbedded in encapsulation. No permissible tolerances.
Automatic part reject.

1.6 Photograph 6:
Wrinkled encapsulation. No permissible tolerances. Automatic part reject.

2. Quality Control Testing for Seal Integrity and Dimensional Properties

Level I-Standard Chemical Seals

2.1 A proprietary inert gas test of encapsulation materials to detect
pinholes in pre-form process.

2.2 Statistical measurement [representative qty] of o-ring batch inside and outside diameters to meet
manufacturing standards per tolerances published in technical bulletin and
at http://www.m-cor.com/html/tolerancechart.html or agreed upon standards.

2.3 Statistical measurement [representative qty] of o-ring batch cross-section to meet manufacturing
standards per tolerances published in technical bulletin and at
http://www.m-cor.com/html/tolerancechart.html or agreed upon standards.

2.4 Proprietary liquid leak test to detect pinholes in encapsulation in
post-form process.

2.5 Each O-ring is washed in IPA solution to ensure cleanliness.

2.6 Orders are packaged and labeled with batches, tolerances, and work order number
to trace batches.

2.7 Quality control report included with every shipment.

3. Surface Imperfections Control II: Critical Application Seals

Level II-Critical Application Seals

3.1 Photograph 1:
Separation in vulcanized elastomer core join area. Permissible gap of up
to 3% of O-ring cross section, only if area is filled with bonding agent.

3.2 Photograph 2:
Stress crack in join area of encapsulation. No permissible tolerances.
Automatic part reject.

3.3 Photograph 3:
Foreign particles (dirt,metal flakes,hair,etc.) on elastomer core material. Permissible particle size of 5% cross section. 5 allowable particles per o-ring.
Metal flakes automatic reject.

3.4 Photograph 4:
Blooming. No permissible tolerances. Automatic part reject.

3.5 Photograph 5:
Carbon deposit imbedded in encapsulation. No permissible tolerances.
Automatic part reject.

3.6 Photograph 6:
Wrinkled encapsulation. No permissible tolerances. Automatic part reject.

4.Quality Control Testing for Seal Integrity and Dimensional Properties

Level II-Critical Application Seals

4.1 All of the above as listed in Level I.

4.2 Individual measurement of o-ring inside and outside diameters to meet
manufacturing standards per tolerances published in technical bulletin and
at http://www.m-cor.com/html/tolerancechart.html or agreed upon
standards.

4.3 Individual measurement of o-ring batch cross-section to meet manufacturing
standards per tolerances published in technical bulletin and at
http://www.m-cor.com/html/tolerancechart.html or agreed upon standards.