Storz coupling fails during hydro test

[S. Cook]

Just recieved this a thought I'd pass it along. Will give updates as I get them.


LESSONS LEARNED STATEMENT: The purpose of this notice is to advise you of an incident so that you can consider taking extra precautions at your facilities to avoid serious injury.

DISCUSSION: During routine annual hose testing, a Storz style coupling on a 100 foot section of 5 inch hose failed. This was not a matter of the jacket slipping from the coupling - the cast aluminum portion of the coupling catastrophically failed. The hose was being tested in a large parking area at the Y-12 Plant, at 200 PSI, per NFPA 1962. This section of the hose was located in the middle of the rolls which had been put together for the test. No personnel were in the immediate area of the hose at the time it failed.

Preliminary examination of the failed coupling indicated that a significant amount of porosity was present in the metal at the plane of fracture.

[Halligan84]

Scott -
During a drill about 2 years ago we had a coupling fail on a piece of Angus 4". This failure occured at the locking collar on to the hose. We haven't had any problems during service testing, just the failure when charged off the plant fire main system.

[S. Cook]

Did the hose pull out of the collar or did the inside collar break?

[S. Cook]

More info. At this time it is requested that the manufacturer not be named as there is some question as to who it is.

- The hose and couplings were purchased in 1997. The vendor that was awarded the contract for the hose stated he was selling a name brand hose and couplings. However, the manufacturer is stating that these are quite possibly be counterfit as the vendor is not an authorized dealer of their product and only the hose is labeled as theirs and not the couplings. The manufacturer stamps their name into the coupling and the only thing marking the coupling at all is a stamp stating "Made in America." Additionally, at this time, none of the other storz manufacturers are claiming responsibility for manufacture of the coupling.

- The coupling is a storz type aluminum alloy with the NFPA required locks on it.

- The failure of the coupling was not at the tabs that insert into the other coupling to make the connection, it occured at a point approx. 3" inside the hose.

- They report that it is obvious the coupling was poorly cast at the time of molding as it was very porous. Metalurgists have determined that the fracture was not the result of any type of previous damage or use to/of the coupling.

- The hose is 5" large diameter hose in a 100' section rated at 200psi

- It passed its 1998 hydro test

- The coupling is attached to the hose with a 3 piece split clamp approx. 2" wide and secured with allen screws.

Also FYI this is an industrial facility and Plant Y-12 simply refers to a specific location on their site.

[This message has been edited by S. Cook (edited August 24, 1999).]