The U.S. Department of Transportation recently released new regulations in an effort to clarify the regulations on periodic inspection and testing of cylinders. Document HM22OA was issued as a final rule with an effective date of October 1,1996. The document can be found in the May 28,1996 Federal Register (Vol.61, Number 103, pages 26749 26764). The important changes include:

1. Clarification that visual inspection, internal and external, are required each time a cylinder is retested.

2. New requirements for accuracy of pressure gauges and expansion indicating devices (burettes, used in water jacket testing:

i) Certified gauges with accuracy of +1/2% of full range.

ii) Pressure gauges readable to +1 % of test pressure,
midpoint interpolation of analog gauges is permitted.
iii) Pressure gauges must be readable from 90% - 110%
of test pressure.
iv) Expansion indicating devices must be accurate to
+1/2%, or better, of its full scale and readable to
+1% or 0.1 cubic centimeter, whichever is larger.
v) Water jacket test equipment must be verified accurate to
+1% each day by the use of a calibrated cylinder.
Note: The above requirements for pressure gauges and
daily verification of system accuracy will also apply to
proof-pressure testers in the very near future!

3. New wording concerning "condemned" cylinder and how to mark them.

4. Requirements for cylinders retested by the proof pressure test method to include the letter "S" next to the test date.

Note: Cylinders retested by the proof pressure method do not currently have to have the RIN number marked on the extinguisher but Amerex recommends that you add your Retesters Identification Number (RIN) to the hydrotest label that is approved by exemption E-11372.

5. A clarification that anyone who hydrotests a DOT specification cylinder using either the water jacket test or proof pressure test must have a RIN.

6. New and clearer wording on how to obtain a RIN.

7. Clarification of what is required to obtain a RIN including :

i) Current copies of 49CFR that apply to retesting of cylinders.

ii) Current copies of all exemptions governing exempt cylinders that are
inspected, retested and marked at that location.
iii)Copies of each CGA pamphlet incorporated by reference that applies to the
retest activities.

8. Record keeping requirements - records to be maintained until expiration of the retest period or until cylinder is again retested, which ever comes first.

Also, system verification records must be kept in daily logs.

9. The paragraph describing retesting of specification cylinders used as fire extinguishers is rewritten and renumbered from 173.34 (e)(18) to173.34 (e)(19).

Note: Paragraph (B) (2) (ii) still contains an error regarding the test interval for 3A, 3AA and 3AL cylinders, especially those used as C02 extinguishers. We believe the correct test interval is 5 years as required by NFPA-1 0.

Note: This rewrite essentially contains everything that
was previously in 173.34 (e) (18) and E-8886.
Basically, all Amerex hand portable dry chemical
and halon extinguishers using DOT specification
cylinders can be proof pressure tested every 12
years. Larger extinguishers such as stored pres-
sure wheeled extinguishers can also be proof
pressure tested, but after the initial 12 year inter-
val, subsequent retests will be required every 7