Viking® VK3521 Pendent Sprinkler | QR | 8.0K | Chrome | 155F | 23878FB

Viking 3/4 in. NPT  XT1 8.0K Quick Response Pendent (VK3521) Fire Sprinkler Head

This Viking QR Pendent Fire Sprinkler features a glass bulb activating at 155F (68C) with a 8.0 K-Factor, and 3/4 in. NPT threads. Each pendent head features a brass frame and stainless steel deflector. The Sprinkler Identification Number (SIN) is VK3521. This is a quick response, standard coverage sprinkler with a maximum working water pressure of 175 PSI.

The VK3521 pendent sprinkler delivers effective, affordable defense against fire in light and ordinary hazard occupancies in commercial building sprinkler systems. Using a heat-activated glass bulb assembly, this automatic fire sprinkler opens when ambient temperatures reach 155F (68C), drenching the area surrounding a fire to keep it in its place of origin.

Viking Pendent Fire Sprinkler XT1 (VK3521) Sprinkler Head Listings and Approvals

Each XT1 upright sprinkler is made by Viking, a global leader in fire protection manufacturing for nearly 100 years. When installed properly, this fire sprinkler head is cULus Listed, VdS Approved, FM Approved, UKCA Approved, CE Listed, MED Approved, and LPCB Approved. Refer to the datasheet for listings and approvals in specific temperatures and/or applications.

The sprinkler is cULus Listed as indicated in Table 5.1 of the datasheet for installation in accordance with the latest edition of NFPA 13 for standard spray sprinklers.

The sprinkler is FM Approved as quick response Non–Storage upright sprinkler as indicated in the FM Approval Guide in the datasheet. The sprinkler is also approved for use in FM Approved vacuum dry sprinkler systems with a maximum supervisory vacuum pressure of –3 psi (–207 mbar).

This pendent sprinkler head has a maximum working pressure of 175 PSI (12.1 BAR) UL, FM and connects to wet piping systems.

Viking XT1 (VK3521) Pendent 3/4 in. 8.0 K-Factor Sprinkler Installation and Other Information

During installation be aware that over tightening will cause permanent damage to the 3/4 in. NPT threads and/or the fire sprinklers themselves. Use the manufacturer approved installation wrench and tighten to a maximum torque of 20 ft-lb (27.1 N-m). Refer to the data sheet for additional storage and installation information.

This pendent sprinkler features a chrome finish and a 155F (68C) temperature. Available finish options include Brass, Chrome, White, and Black. White Polyester Painted (White), and Flat Black Polyester Painted (Black) are UL Listed as corrosion resistant. Temperature options include 135F (57C), 155F (68C), 175F (79C), 200F (93C), and 286F (141C). Finish and temperature combinations available in the “Options” section at the top of this product page.

The VK3521 listed accessories include the approved Viking Wrench (part no. 23559MB), the approved Viking Recessed Wrench (23560MB), the Viking XT1 Model XG Head Guard (part no. 23930), and the approved Viking escutcheon(s). Commonly purchased with fire sprinkler head cabinets and sprinkler shut off tools. These products are available in the “Frequently bought together” products section at the top of this product page.