We have discussed the critical role of “torque” in constructing our chemical processes. I catch a lot of flack for my insistence on this critical function, for which I am genuinely surprised. But our piping design and construction RAGAGEP (ASME B31.3) is pretty clear on the matter, and now OSHA and EPA have “caught on” and are issuing citations where there is an LOPC event from a flanged connection. Here are the B31.3 requirements OSHA/EPA are referencing in their citations:
(emphasis by me)
|
335.2.2 Bolting Torque (a) In assembling flanged joints, the gasket shall be uniformly compressed to the proper design loading. (b) Special care shall be used in assembling flanged joints in which the flanges have widely differing mechanical properties. Tightening to a predetermined torque is recommended. |
Some recent OSHA citations…
Citation 1 Item 5
Type of Violation: Serious; $11,934
29 CFR 1910.119(d)(3)(ii): The employer did not document that equipment complies with recognized and generally accepted good engineering practices (RAGAGEP):
…
b) Ethylene Oxide Batch Plant – On or about November 25, 2018, the employer failed to document it complied with its chosen RAGAGEP, ASME B31.3 (2016), Process Piping, Section 335.2.2, Bolting Torque when it assembled piping flanges in ethylene oxide service that WERE NOT TORQUED TO THEIR PROPER DESIGN LOADING including the flange bolts on the 1/2″ inch vent line of the Purification Column Steam Reboiler E-430 in Area 400 that was involved in the ethylene oxide release. In addition, approximately 85 other flanges were found post-incident to be under-torqued in Areas 400 and 1400 of the EO plant.
Citation 1 Item 16
Type of Violation: Serious; $11,934
29 CFR 1910.119(j)(6)(ii): Appropriate checks and inspections were not performed to assure that equipment was installed properly and consistent with design specifications and the manufacturer’s instructions:
a) Ethylene Oxide Batch Plant – On or about November 25, 2018, the employer failed to assure that pipe joints were assembled correctly. In particular, the employer failed to recognize that a gasket, made of materials incompatible with ethylene oxide, was used on a vent line flange at Reboiler E-430, part of the Ethylene Oxide Purification Section.
b) Ethylene Oxide Batch Plant – On or about November 25, 2018, the employer failed to assure that the studs used in the flange assembly were constructed of the correct materials.
c) Ethylene Oxide Batch Plant – On or about November 25, 2018, the employer failed to assure that piping flanges were torqued correctly. These conditions contributed to employee exposure to the toxic, fire, and explosion hazards posed by ethylene oxide.