KINGSBURY, IN. Alexander Chemical Corporation enlisted the expertise of Steigerwalt Associates for a prefill inspection & maintenance practice for class dot 106A500 multi-unit tank car tanks for chlorine transport known as “Ton Containers”.
Pre Fill Inspection Handling:
Compressed Gas Association Pamphlet C-6, 1993, incorporated in 49 CFR 180.159, Periodic Retest & Inspection of Tank Cars other than Single-Unit Tank Car Tanks, requires that a Tank shall be condemned [scrapped] if the tare weight is less that 90% of the original tare weight or rejected [subject to requalification] if the tare weight is less than 95% of the original tare weight. Upon passing requalification, a new tare weight shall be marked on the Tank.
Chlorine Institute Pamphlet 17, November 2017, Packaging Plant Safety & Operational Guidelines, is the chlorine industry operating procedure guidance document. Pamphlet 17 pre-fill procedures are identical to the CGA C6 criteria as they apply to pre-fill inspection and tare weights.
Alexander’s Standard Operating Procedures are listed as references below; all exceed regulatory or industry practices for pre-fill inspections and ton handling practices of DOT 180.519 Pamphlet C6 and Chlorine Institute Pamphlet 17.
Alexander conducts a pre-fill inspection of all Chlorine tons and looks for corrosion, denting or damage to the valves or safety relief devices.
If a tare weight loss of 25 pounds [approximately 1.5% of the tare weight] is detected or if any damage is noted on valves or safety devices, the ton is retested, and a new tare weight marked and the valves and safety relief devices are replaced.
If a tare weight loss of 50 pounds [approximately 3% of the tare weight] is detected the ton is scrapped.
Valves are given particularly detailed scrutiny not required by DOT regulations or Pamphlet 17 practice: valves remain in service for either 5 or 8 filling cycles. After this many fills, the valves are dissembled and rebuilt on-site to new standards with OEM replacement parts.
Ceodeux valves are used exclusively in Chicago tons and are rebuilt every 10 fill cycles. Chicago tons are also in dedicated service: used exclusively for Chicago.
Based on the review conducted by Steigerwalt Associates, the following was determined:
- Alexander pre-fill and requalification procedures exceed the regulatory requirements of the US-DOT for Class 106A ton containers & industry practices delineated in Compressed Gas Association Pamphlet C-6 & Chlorine Institute Pamphlet 17.
- Alexander also asked us to comment on possible service life limits for tons. Class 106A ton containers do not have service life limits under DOT regulatory requirements or industry practices.
Tons are requalified for continued service, as a minimum, on a five year cycle as specified in 49 CFR 180.519. They are returned to continued service of upon passing this periodic retest.