Outer threaded plastic cap for fire department (Siamese) connection, 2.5 inch, with chain for Quebec

2.5" Plastic External Threaded Cap for Fire Department Connection (Siamese) – QST Thread (Quebec)

This high-density plastic cap is designed to protect the female inlets of fire department connections (Siamese connections). Featuring the QST (Quebec Standard Thread), it is the standard accessory for ensuring compliance and protecting fire protection systems throughout the province of Quebec.

Why Choose This External Threaded Cap?

• Siamese Inlet Protection: Unlike standard caps, this model features an external (male) thread designed to screw directly into the female swivel couplings of a building's water inlets.

• Obstruction Barrier: Prevents the entry of debris, snow, ice, or vandalized objects (such as cans or stones) that could clog the standpipe and prevent firefighters from supplying water to the system.

• Theft Deterrence: Made of robust technical plastic, it has no scrap metal resale value, significantly reducing the risk of theft compared to brass models.

• Secure Installation: The included retaining chain allows the cap to be secured to the body of the Siamese connection, ensuring it doesn't fall or get lost during an emergency.

Technical Specifications

• Nominal Diameter: 2.5 inches (65 mm).

• Thread Type: External (male), QST (7 threads per inch).

• Material: Robust high-density plastic, often in red or black for high visibility.

• Accessory: Included steel safety chain.

• Application: Siamese connections and fire department inlets in Quebec.

Frequently Asked Questions (FAQ)

What is the difference between this model and an internal threaded cap?

An external threaded cap screws inside a female fitting (like a Siamese inlet), whereas an internal threaded cap screws onto a male fitting (like a fire valve outlet).

Is this cap compliant with fire department requirements?

Yes, in Quebec, the primary requirements are thread compatibility (QST) and protection against obstructions. This cap fulfills both safety functions perfectly.

Can I install this on a Siamese connection in Ontario?

No. In Ontario, fittings generally use the CSA thread. A QST cap will not screw correctly into a CSA inlet due to the difference in threads per inch.

Is the plastic UV resistant?

Yes, it is manufactured from a polymer treated to resist ultraviolet rays and the extreme temperature fluctuations of the Quebec climate, preventing it from becoming brittle over time.

OHS Expert Advice

A Siamese inlet without a cap is a major failure in your fire protection system. If an object blocks the check valve inside the connection, firefighters will be unable to pressurize your sprinklers. Switching to plastic is an excellent solution for owners tired of replacing stolen brass caps. Simply ensure that the swivel couplings on your Siamese connection still rotate freely before screwing in your new cap.

Do you need additional safety equipment?

Check out these items:  18-inch orange warning cone (EPTCONE), yellow plastic monthly inspection tag (IPTAG4), 10 lb class ABC portable powder fire extinguisher (EXABC10), outdoor plastic surface cabinet (EC9), 20 lb portable powder fire extinguisher (EXABC20).

Under “Accessories” at the bottom of the page. If you are looking for work equipment, check out the following products: Stopper II cover without local alarm (ECSTI1200FRE), manual wall-mounted fire alarm station (ECST270), or Weather Stopper cover (ECSTI3150FRE).

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