Home
gpo.gov
govinfo.gov

e-CFR Navigation Aids

Browse

Simple Search

Advanced Search

 — Boolean

 — Proximity

 

Search History

Search Tips

Corrections

Latest Updates

User Info

FAQs

Agency List

Incorporation By Reference

eCFR logo

Related Resources

Electronic Code of Federal Regulations

We invite you to try out our new beta eCFR site at https://ecfr.federalregister.gov. We have made big changes to make the eCFR easier to use. Be sure to leave feedback using the Help button on the bottom right of each page!

e-CFR data is current as of September 22, 2020

Title 30Chapter ISubchapter BPart 33Subpart C → §33.37


Title 30: Mineral Resources
PART 33—DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN COAL MINES
Subpart C—Test Requirements


§33.37   Test procedure.

(a) Roof drilling: Drilling shall be done in friable strata, similar to the roof in the Bureau's Experimental Mine, which tends to produce large scale-like cuttings.

(b) Horizontal drilling: Drilling shall be done in strata comparable in hardness to that of coal-mine draw slate. Holes shall be started near the roof of the test space under conditions simulating the drilling of draw slate in coal mining.

(c) Down drilling: Drilling shall be done in typical mine floor strata with a pneumatic percussion-type drill. Five holes shall be drilled vertically and five holes shall be drilled at an angle.

(d) At MSHA's discretion drilling in “on site” strata may be acceptable in lieu of strata requirements in paragraphs (a), (b), and (c) of this section. (See §33.20(a).)

Need assistance?