Skip to content
U.S. Department of Labor

Mine Safety and Health Administration
201 12th Street South, Suite 401
Arlington, VA 22202-5450

ISSUE DATE: March 18, 2013


FROM:              KEVIN G. STRICKLIN  
                       Administrator for
                       Coal Mine Safety and Health

                      GEORGE M. FESAK   GEORGE M. FESAK
                       Director of Technical Support

SUBJECT:    Temporary Suspension of MSHA Approval of the 50 psi MINOVA
                        Gob Isolation Tekseal Design

Underground bituminous coal mine operators, miners' representatives, independent contractors, Mine Safety and Health (CMS&H) enforcement and Technical Support personnel, manufacturers of materials, and other interested parties need this information.

This Program Information Bulletin (PIB) notifies the mining industry of an immediate, temporary suspension of the Mine Safety and Health Administration's (MSHA's) approval of the 50 psi Minova Gob Isolation Tekseal design (50G-03.0). This PIB also informs the mining industry of the need to immediately increase inspections of these newly-constructed Minova seals.

Until further notice, MSHA has suspended its approval of the 50 psi Minova Gob Isolation Tekseal design (50G-03.0) in response to a request from Minova. MSHA has taken this action to reduce risk to underground coal miners from Minova seals that are deficient as determined by in-situ testing performed by Minova following their prescribed testing protocol.

Mine operators with an approved 50 psi Minova Gob Isolation Tekseal design (50G-03.0) in their ventilation plan must cease construction of these seals immediately. The 50 psi Minova Mainline Tekseal design (50M-02.0), 120-psi Minova Gob Tekseal design (120G-05.0), and the 120-psi Minova Mainline TekSeal design (120M-02.0) could be used (along with other approved seal designs) in lieu of the 50-psi Minova Gob Isolation TekSeal (50G-03.0).

Additionally, within a 60 day period from the date of issuance of this PIB, mine operators must perform the in-situ testing as prescribed by Minova's testing protocol on accessible 50-psi Minova Gob Isolation Tekseals that passed the standard quality control tests. These in-situ test results must be provided to the District Manager within seven days after commencement of the in-situ testing. Any 50-psi Minova Gob Isolation Seal that does not pass Step 1 of Minova's protocol will be deemed deficient and must be replaced. In-situ testing using Minova's protocol must be completed withing the 60-day time period.

On July 17, 2012, an MSHA, Technical Support specialist, along with Minova representatives, examined the 2nd Right set of 50-psi Minova Gob Isolation Tekseals (50G-03.0) at Bull Mountain Mine. Several of the seals failed to pass the in-situ testing performed by Minova personnel following Minova's prescribed testing protocol. Based on Minova's seal design and testing protocol performed on the longwall gob isolation seals at the Bull Mountain Mine, these seals were determined to be deficient in cured strength and inadequate to protect underground coal miners' safety. MSHA notified Minova of the problem found with the integrity of the Minova 50-psi Gob Tekseal Design (50G-03.0). As a result of these deficient seals and the cause not yet determined, MSHA has concerns with the design methodology used in the approved plan.

This PIB applies to the following Minova seal with an MSHA design approval (formerly posted on MSHA's web page):

  • 50G-03.0 MINOVA Gob Isolation Tekseal
  • Authority
    The Federal Mine Safety and Health Act of 1977, as amended, 30 U.S.C. 801 et seq.; and 30 C.F.R. 75.335, 75.360(b)(5), and 75.364 (b)(4).

    Issuing Office and Contact Persons
    Coal Mine Safety and Health, Safety Division
    Erik Sherer, (202) 693-9523

    Technical Support, Pittsburgh Safety and Health Technology Center
    John Urosek, (412) 386-6936

    MSHA Program Policy Manual Holders
    Underground Coal Mine Operators
    Miners' Representatives
    Special Interest Groups