The counterfeit 3351 fire sprinkler was not produced by Tyco Fire Products and has not been tested by FM Approvals. As such, these automatic sprinklers cannot be relied upon to react to or control a fire.
Failure by any of the following mechanisms is possible: failure of the thermal element, orifice leakage, premature or delayed operation, bulb strutting (incomplete fracture), ejection of the deflector, inadequate or excessive discharge rate, corrosive attack, failure to operate, failure to produce an adequate discharge pattern, etc.
Of further note is the suspected use of an o-ring type orifice seal, a design which has historically been proven to be unreliable and possibly dangerous. Some o-ring type sprinklers have been subject to recall per the Consumer Product Safety Commission.
The authentic Tyco TY3351 sprinkler in white polyester finish.
The wrench boss marking reads "TYCO" in sunken letters on the authentic sprinklers, and both utilize a 5 mm diameter frangible bulb.
Markings on the authentic Tyco TY3351 deflector. This sprinkler has a plain brass finish to show the markings clearly. Authentic TY3351 sprinklers in polyester have identical markings but are not as easily legible due to the thickness of the white finish.
The counterfeit sprinkler frame is a completely different shape in both the wrench boss and frame arms.
The wrench boss marking uses raised "TYCO" lettering on the counterfeit sample while the authentic uses sunken letters.
The counterfeit sprinkler marking reads "JOB F5." It is unknown whether the bulb was manufactured by Job GmbH or is also counterfeit.
The authentic sprinkler utilizing a Job 5 mm bulb will have the "G5" model designation.
The counterfeit sprinkler deflector design is completely different from the deflector used on authentic TY3351 sprinklers.
The white finish has chipped or worn off, indicating a poor finish bond.
The counterfeit threads are not machined to the NPT standard and have a very slight taper, if any.
It appears that the brass/copper finish on the inlet threads is a coating or plating, and the base metal does not appear to be a copper based alloy.
Waterway inlet view of the authentic Tyco 3351 sprinkler (left) and the counterfeit sprinkler (right).
The counterfeits seal resembles sprinklers employing a silicone o-ring design, which has an extensive history of problem leakage and non-operation.