3.2.1

1. 3.2.1 Examining DOT Cylinders to Determine Their Condition and Fitness for Continued Service Before propane cylinders approved for refilling can be filled with propane, they must be inspected to assure they are in good condition for continued service. • In this module you will learn to identify: • Required DOT/ICC cylinder markings • Physical conditions indicating a cylinder should not be filled • Overfilling prevention device requirements for DOT cylinders

2. Required DOT/ICC Cylinder Markings Cylinder—a container constructed in accordance with the U.S. Department of Transportation specifications (Title 49, Code of Federal Regulations). The maximum size permitted under DOT specifications is 1,000 lbs. water capacity. DOT cylinders range in size from one-pound disposable cylinders to 420 pound stationary cylinders. All DOT cylinders must be legibly marked with the appropriate DOT/ICC design code. NFPA 58

3. Design Information— Every cylinder used to store propane must be marked with a DOT or ICC design code, its water capacity in pounds, and its tare weight. • CYLINDER MARKINGS • DOT (ICC) Specifications. See list of specifications authorized for propane. • Manufacturer's Inspector's Symbol. In this case, the (P) is the registered symbol for Lee Cylinder's chief inspector. • Month and year of manufacturer's test & inspection. • Manufacturer's, Owner's or User's Symbol. (Must be registered with RSPA.) • Serial Number. This number together with the symbol identifies the one cylinder on which it appears. It may be used to identify the manufacturer's inspector's report as to material and required test data. Required DOT/ICC Cylinder Markings

4. Design Information • CYLINDER MARKINGS • The figure following "DT" is the correct length of the dip tube in inches and decimal fractions, which should be used for volume filling of this size and type cylinder. • Tare (empty) weight of the cylinder with valve to be used when filling by weight or verifying filling by volume. • Water capacity in pounds when filled to 100% of capacity. For propane capacity see "list of typical filling limits." • NOTE: The following information often appears in the stamping and is optional. • 9. Owner's name and address • The word "RETEST" indicating space for retest or periodic inspection marking. See: Notes on cylinder requalification. • The cylinder manufacturer's name and trademark. Required DOT/ICC Cylinder Markings

5. Figure 2. Typical DOT and ICC Cylinder Codes Required DOT/ICC Cylinder Markings

6. Requalification Requirements • Requalification is done by one of three methods: • A date without a letter indicates the cylinder was subjected to a complete water jacket hydrostatic (“volumetric expansion”) test. The next requalification must be within 12 years. • The letter "S" following the date indicates a proof pressure test has been performed. In this case, the cylinder must be requalified within seven years of the marked date. • If the letter "E" follows the test date, this indicates a recorded external visual inspection, and requalification of the cylinder is required again within five years of the marked date.

7. Requalification Requirements All cylinders must be requalified before their due date. Figure 3. Requalification Stamp for External Visual Inspection Performed in October 2003

8. Valid for 5 years from the date Valid for 5 years from the date Valid for 5, 7 or 12 years from the date, depending on the meaning of “x” V10001 0604 E V10001 0604 E 0604 E V10001 Requalification Requirements Requalification Markings

9. DOT Definitions Condemn means a cylinder is unserviceable for the continued transportation of hazardous materials in commerce, and that the cylinder may not be restored by repair, rebuilding, requalification, or any other procedure. Defect means an imperfection requiring removal of a cylinder from service. Filled or charged means an introduction or presence of a hazardous material in a cylinder. Rejected cylinder means a cylinder that cannot be without repair, rebuilding, and requalification.

10. DOT Definitions Requalification means the completion of a visual inspection and/or the test(s) required to be performed on a cylinder to determine its suitability for continued service. Requalification identification number or RIN means a code to uniquely identify a cylinder requalification, repair or rebuilding facility. Cylinders with a series of XXXs over the DOT specification number and marked service pressure or stamped with “CONDEMNED” on the shoulder, top head, or neck are condemned cylinders which must not be refilled or continued in service.

11. Rejection Criteria DOT regulations require a visual inspection of each cylinder before filling. If any of the following are found, the cylinder must not be refilled: • crack or leak • bulging • defective valve • defective or leaking pressure relief device • evidence of physical abuse, fire or heat damage, or detrimental rusting or corrosion • damage to the cylinder valve, valve protection, and cylinder foot rings

12. Rejection Criteria Steel cylinders subjected to fire are required to be requalified, reconditioned, or repaired. Repairs are performed only by a manufacturer of the type of cylinder to be repaired, or by a repair facility authorized by DOT. Steel cylinders subjected to fire and not requalified, reconditioned, or repaired, must be permanently removed from service. DOT 4E (aluminum) cylinders subjected to fire must be permanently removed from service.

13. Figure 4a. Neck Ring Damage Figure 4b. Bulging & Fire Exposure Rejection Criteria Cylinders Which Must Be Rejected

14. Figure 4c. Corrosion Pitting Figure 4d. Damaged Foot Ring Rejection Criteria Cylinders Which Must Be Rejected

15. Figure 4e. Excessive General Corrosion Figure 4f. Dent at Weld Rejection Criteria Cylinders Which Must Be Rejected

16. Overfill Prevention Device Requirements An overfilling prevention device (OPD) is a special cylinder service valve which stops the flow of gas liquid into the cylinder when the cylinder is about 80% filled. Effective April 1, 2002, no cylinder in the 4 through 40 vapor cylinder sizes shall be filled unless it is equipped with an overfilling prevention device and a fixed maximum liquid level gauge of the proper length in jurisdictions that have adopted NFPA 58, 1998 or 2001 editions without modifications or exceptions. OPD cylinder valves are distinctively marked and are equipped with a unique handwheel, a modified triangle, to make identification easier.

17. Overfill Prevention Device Requirements Figure 6. OPD Handwheel & Marks Figure 5. OPDs for DOT Cylinders 4 lbs. Through 40 lbs. Capacity

18. Overfill Prevention Device Requirements Overfilling prevention devices are intended to be a secondary means to protect against overfilling of cylinders. The primary method to prevent overfilling is filling by weight on a scale periodically checked for weighing accuracy by a state weights and measures agency. Figure 7. Another OPD Design

19. Time to See If You Got the Key Points of This Module… • Complete the Review on pages 9-11. • See if you are ready for the Certification Exam by checking off the performance criteria on page 12.