You will find in this section many frequently asked questions.

If you do not find your answer, please contact us.



In Canada, the ULC Laboratories offer these services

They can be contacted at:


7 Underwriters Road

Toronto, Ontario   M1R 3A9

Telephone : (416) 757-3611

Fax : (416) 757-8727

E mail : cec@ul.com




6505 Trans-Canada Highway, suite 330

St-Laurent, Quebec  H4T 1S3

Telephone : (514) 363-5941

Fax : (514) 363-7014

Courriel : cec@ul.com


Today’s sprinklers are offered in a vast selection of finishes and material. Sprinklers offering superior corrosion resistance are usually coated or made of a corrosion resistance material. Our partner Viking Corporation offers a specific bulletin concerning corrosion resistance for all the sprinkler finishes they offer see link). These are good guidelines to choose the best sprinkler for your application. http://www.vikinggroupinc.com/databook/bulletins/012513.pdf


Storage sprinklers are offered in a large selection of K-Factors, orifice size and types.

Typically, all sprinklers are built and tested to control a fire even if numerous fires end up being put out by proper sprinkler activation. The only exception to this ‘’control mode’’ are the sprinklers listed and tested meeting the ‘’ESFR’’ requirements. ESFR means Early Suppression Fast Response. Suppression means that these sprinklers have passed specific tests to put out a fire and not only control it.

There are also CMSA sprinklers which means Control Mode Specific Application. Always refer to the manufacturers specification sheets to identify the proper circumstances where these sprinklers are to be used.

Once again, our partner Viking Corporation offers different sprinkler Quick Reference guides to help with your choices (see link).






The electrical characteristics of Protectowire Linear Heat Detector are approximately as follows.

Resistance: 0.2 Ohms per foot (0.656 Ohms per Meter)

Capacitance: 30pF per foot (98.43pF per Meter)

Inductance: 2.5uH per foot (8.2uH per Meter) (Values shown reflect twisted pair)

Reference: www.protectowire.com

The electrical characteristics of the Protectowire Linear Heat Detector could pose compatibility issues when employed on panels manufactured by others. The system designer must confirm Protectowire Linear Heat Detector compatibility with the panel manufacturer. Protectowire controls specifically designed and approved for use with Protectowire Linear Heat Detector are recommended to insure compatibility.

Reference: www.protectowire.com

Yes, Protectowire Linear Heat Detectors (excluding Tri-Wire) have the same internal construction and can be spliced directly together on the same initiating device zone. This allows a single Protectowire Linear Heat Detector zone to protect multiple areas with different ambient temperatures.

Reference: www.protectowire.com

The listed spacing shall be used as a guide or starting point in detector installation layout. Reduced spacing is required based upon factors such as ceiling height and construction, physical obstructions, air movement, or the Authority Having Jurisdiction (AHJ). The maximum listed spacing for each type of Protectowire Linear Heat Detector are as follows:

Factory Mutual Listed Spacing All temperature ratings except 356°F of Types EPC, EPR, XCR, and XLT – 30 feet  (9.14 meters) on center, Type TRI – 15 feet (4.6 meters) on center. 356°F EPC, EPR and XCR proximity detection only.

Underwriters Laboratories Listed Spacing All temperature ratings EPC, EPR, XCR, and XLT  – 50 feet  (15.24 meters) on center, Type TRI – Not UL Listed

Reference: www.protectowire.com

The Protectowire Company has researched and selected a complete assortment of mounting hardware and installation accessories suitable for a variety of applications and environments. Protectowire approved fasteners are generally designed to lightly clamp the detector, which enables a tension to be applied progressively. This method is better than arrangements that apply a high tensile load to the detector, or clamp and compress the detector so tightly that it becomes damaged.

To ensure a trouble free installation, only Protectowire supplied or approved mounting hardware and accessories should be used. The use of non-approved mounting hardware and accessories may physically damage the detector thereby causing “false alarms” and in some cases void the detector’s warranty.

Reference: www.protectowire.com

Protectowire Linear Heat Detector is available in models which are suitable for installation in ambient temperatures ranging from -60°F (-51°C) to 250°F (121°C). Refer to the Protectowire Linear Heat Detector data sheet DS-6592 for appropriate temperature and model selection.

Reference: www.protectowire.com

Mounting Protectowire Linear Heat Detector directly to sprinkler pipes is common practice when the detector is the initiating component of an extinguishing system. In this instance Protectowire Linear Heat Detector is considered an integral component of the extinguishing system and typically is allowed by most Authorities Having Jurisdiction (AHJ). Consult the local Authority Having Jurisdiction for acceptability prior to installation.

Reference: www.protectowire.com


No, they do not mean the same thing. NFPA 13 2010 Section defines a quick response sprinkler as a type of spray sprinkler that meets the fast response criteria of 3.6.1(a) (1) and is listed as a quick response sprinkler for its intended use. For further information on this, please follow the link provided below to a technical article we have available that goes into much further detail on this question: https://www.vikinggroupinc.com/sites/default/files/documents/Automatic%20Sprinkler%20Thermal%20Sensitivity.pdf

Reference: www.vikingcorp.com

The Viking Corporation does not now use, and has never used, O-ring technology to seal the waterway of any sprinklers we manufacture.

Viking designs use belleville spring seals to close the waterway of its sprinklers. With Viking sprinklers, force is transmitted from a set-screw through a fusible element or glass bulb to a belleville spring seal to close the waterway. When the sprinkler is heated to its operating temperature, and the fusible element or glass bulb activates, the tension on the spring is released causing the belleville spring seal to open the waterway even if there is no water pressure in the sprinkler.

The following links describe sprinklers being investigated and/or recalled because of performance issues related to O-ring seals.

To learn more, visit the following links:



Reference: www.vikingcorp.com

You cannot use anything to seal this gap.  The air gap between the ceiling and the cover is there so that the heat can travel up to the sprinkler to start heating the thermal element prior to the release of the cover plate. Viking does offer a concealed cover plate that is listed with a gasket around the cover. https://www.vikinggroupinc.com/cleanroom-sprinkler-cover-assembly


Reference: www.vikingcorp.com

Viking offers a concealed cover plate that is listed with a gasket installed around the cover to help prevent dust from reaching the room below, from the plenum above. https://www.vikinggroupinc.com/cleanroom-sprinkler-cover-assembly


Reference: www.vikingcorp.com

Yes, Viking offers an MRI sprinkler which is made of non-ferrous materials, and has been tested in up to a 3-Tesla MR system environment. https://www.vikinggroupinc.com/sites/default/files/documents/MR%20Systems.pdf


Reference: www.vikingcorp.com

No, the dry sprinklers do not have pressurized air in the barrel. The dry sprinklers have a brass seal which is held in place until the sprinkler has activated. Once the sprinkler has activated, the brass seal will clear the waterway, and water will flow into the barrel of the sprinkler.

Reference: www.vikingcorp.com