*Obsolete* Viking® VK4921 Concealed Pendent Sprinkler | SR | 5.6K | 175F | 24683AD

The VK4921 is now obsolete in 175F. For other temperature options, visit this page.

Viking Standard Response Concealed Pendent (VK4921) Fire Sprinkler Head

This Viking Concealed Pendent Fire Sprinkler features a glass bulb activating at 175F (79C) with a 5.6 K-Factor, and 1/2 in. NPT threads. Each concealed pendent head features a bronze deflector and Steel Cover Adapter. The Sprinkler Identification Number (SIN) is VK4921. This is a standard response, standard coverage sprinkler with a maximum working water pressure of 250 PSI (UL), 175 PSI (FM).

The VK4921 concealed pendent fire sprinkler delivers effective, affordable defense in hazard occupancies up to and including Ordinary Group II. Using a heat-activated glass bulb assembly, this automatic fire sprinkler opens when ambient temperatures reach 175F (79C), drenching the area surrounding a fire to keep it in its place of origin. For concealed application, refer to data sheet for installation instructions with the approved Viking cover(s).

Viking Concealed Pendent SR Fire Sprinkler (VK4921) Sprinkler Head Listings and Approvals

Each Concealed pendent sprinkler is made by Viking, a global leader in fire protection manufacturing for nearly 100 years. When installed properly, this fire sprinkler head maintains listings and approvals from cULus (Category VNIV), and is FM Approved (Class 2015). Refer to the datasheet for listings and approvals in specific temperatures and/or applications.

Concealed Pendent Sprinkler VK4921 is cULus Listed as standard response for installation in accordance with the latest edition of NFPA 13 for standard coverage pendent spray sprinklers as indicated in the Design Criteria chart in the datasheet.

Viking Concealed Pendent Sprinkler VK4921 is FM Approved as a standard response Non-Storage concealed pendent sprinkler as indicated in the FM Approval Guide in the datasheet.

This concealed pendent head has a maximum working pressure of 250 PSI (17.2 BAR) UL, 175 PSI (12 BAR) FM, and connects to wet piping systems.

Viking SR Concealed Pendent (VK4921) Sprinkler Installation and Other Information

During installation be aware that over tightening will cause permanent damage to the 1/2 in. NPT threads and/or the fire sprinklers themselves. Use the manufacturer approved installation wrench and tighten to a maximum torque of 14 ft-lb (19 N-m). Refer to the data sheet for additional storage and installation information.

This standard response concealed pendent sprinkler is available in three temperatures: 155F (68C), 175F (79C), and 200F (93C). To select your temperature, visit the “Options” section at the top of this product page. Additionally, use the Cover Plate option to select a Cover Plate finish and temperature.

The VK4921 listed accessories include the approved Viking Wrench (part no. 23143), the Viking Cover Plate installation tool(s) (part no. 14867, 14412) and the approved Viking Cover(s) (part no. 23190, 23174), which are available in a variety of finishes. 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.