FAQs – Qualifications

The following frequently asked questions (FAQs) address situations involving installation.  If you don’t see the question that addresses your concern, we have other FAQs that could assist you. You can also visit our Product Approvals page.


LOKRING ASME B31 Qualifications and Testing

Find out about our stainless and carbon steel LOKRING fittings that are qualified to the ASME B31.1, B31.3, B31.4, B31.5, B31.8 and B31.9 requirements


How is the Lokring fitting superior to welding?

Lokring fittings can be installed without hot work, allowing the fittings to be installed in areas where solvents and other chemicals may be present. Lokring fittings offer “no heat-affected zone” where a weld is susceptible to accelerated corrosion. In addition, Lokring will eliminate weld slag, incomplete fusion, weld suckback, the need for passivation, and x-ray. Some of the other advantages are as follows: schedule improvements, elimination of hot boxes, establishing fire watches, and the need for highly-skilled welders which can be used in other areas such as structural steel, boiler work, and high alloy steels.


Where Lokring fittings are accepted and code qualified.

“ASME does not ‘approve’, ‘rate’ or ‘endorse’ any item, construction, proprietary device or activity.” This information can be found on the back of the title page of the B31.1 and B31.3 codes. However, ASME B31 does provide nominal guidelines and requirements for the owner, designer, manufacturer, and constructor to qualify materials and piping product forms, whether proprietary or not. Under the B31 codes, the Lokring fitting would be considered a “proprietary” mechanically attached coupling.

To meet the intent of the B31 codes, Lokring:

  1. Provided a design that meets the intents of B31.1 and B31.3.
  2. Provided material and workmanship in accordance with B31.1 and B31.3.
  3. Thoroughly tested to validate the fitting to develop product form design data in accordance with the appropriate requirements of B31.1 and B31.3. Lokring fittings may also meet the requirements of B31.4 and B31.8.  Contact your Lokring Distributor for more detail.
  4. Developed an installation procedure for the fabricator to ensure that final assembly procedures and installation for which the design data apply.