Testing and Certifications
LOKRING fittings have been approved unconditionally by the American Association of Railroads (AAR) for installation on interchange service freight cars since 1997.
In order to meet the demands of the rail industry, LOKRING fittings have been subjected to a signifcant testing program. Test Report #TR93-008, “Qualification Testing of LOKRING Carbon Steel Fittings”, advises on ASME B31 piping qualifications for pressure ratings and stress intensification factors consistent with code guidelines and requirements.
LOKRING fittings have been subjected to burst, flexural, vibration, torsion, tensile, corrosion, fire, high temperature soak and steam thermal cycling testing.
Typical Railcar Applications
Typical applications for LOKRING fittings include, but are not limited to, the following locations:
Branch pipe tee connection — 1 each 1-1/4”. If the car is equipped with a brake pipe reduction device, it will require a second tee connection.
Control valves — 3 each 3/4” flange couplings, may be straight or 90°, depending on brake cylinder design. Also some cars are equipped with an extra reservoir and would require an extra coupling.
Combined reservoirs — 2 each 3/4” flange couplings, may be straight or 90°, depending on brake cylinder design. Also some cars are equipped with an extra reservoir and require an extra coupling.
Retaining valve — 1 each 3/8” NPS flange.
Brake cylinders — 1 each 1/2” or 3/8” flange with or without a brake cylinder measurement tap opening.
Empty/load equipment which will require a flange for each valve connected, between 4 and 6 each 1/2” or 3/8”. Straight couplings for train line 1-1/4”.
Scope of Specification
This specification covers LOKRING pipe fittings manufactured from high strength, low alloy carbon steel. Fittings are qualified on carbon steel nominal pipe (NPS) from 3/8” through 1-1/4”. For fitting dimensions, refer to the product specification sheets.
For installation procedures and selection of tooling see specification LP-105.
Fitting Material Specification: Fitting body and swaging rings are manufactured from high strength, low alloy carbon steel. Material shall conform to ASTM A675 with the chemical composition and mechanical properties as listed in LOKRING specifications for the material. For shelf-life corrosion protection, machined fittings shall be subjected to a black oxide process, followed by a rust inhibiting dip. Contact LOKRING for material or process specifications.