MICROFAST
®
QUICK
RESPONSE FUSIBLE
ELEMENT UPRIGHT
SPRINKLER VK328 (K4.2)
TECHNICAL DATA
Page 1 of 3
Form No. F_071114 21.03.05 Rev 21.1
The Viking Corporation, 210 N Industrial Park Drive, Hastings MI 49058
Telephone: 269-945-9501 Technical Services: 877-384-5464 Fax: 269-818-1680 Email: [email protected]
Visit the Viking website for the latest edition of this technical data page www.vikinggroupinc.com.
1. DESCRIPTION
The Viking Microfast
®
Quick Response Upright Fusible Element Sprinkler
VK328 is a small, thermosensitive, solder link spray sprinkler available
in several different finishes and temperature ratings to meet design
requirements. The special Polyester and Electroless Nickel PTFE (ENT)
coatings can be used in decorative applications where colors are desired.
In addition, The ENT coating has been investigated for installation in
corrosive environments and is listed/approved as indicated in the Approval
Chart(s).
2. LISTINGS AND APPROVALS
cULus Listed:
Category VNIV
Refer to Approval Chart and Design Criteria for cULus Listing requirements that
must be followed.
3. TECHNICAL DATA
Specifications:
Minimum Operating Pressure: 7 psi (0.5 bar)*
Maximum Working Pressure: 175 psi (12 bar) wwp.
Factory tested hydrostatically to 500 psi (34.5 bar)
Testing: U.S.A. Patent No. 4,831,870
Thread size: 1/2” NPT, 15 mm BSPT
Nominal K-Factor: 4.2 U.S. (57 metric**)
Overall Length: 2-3/16” (56 mm)
*cULus Listing, FM Approval, and NFPA 13 installs require a minimum of 7 psi (0.5 bar). The minimum operating pressure for LPCB and CE
Approvals ONLY is 5 psi (0.35 bar).
Material Standards:
Frame Casting: Brass UNS-C84400
Deflector: Brass UNS-C23000 or Copper UNS-C19500
Bushing: Brass UNS-C36000
Fusible Element Assembly: Nickel Alloy
Trigger and Support: UNS-S31603
Belleville Spring Sealing Assembly: Nickel Alloy, coated on both sides with PTFE Tape
Seat and Insert Assembly: Copper UNS-C11000 and Stainless Steel UNS-S30400
Screw: Brass UNS-C36000
For Polyester Coated Sprinklers: Belleville Spring-Exposed
For ENT Coated Sprinklers: Belleville Spring-Exposed, Screw-ENT Plated, Pip Cap-ENT Coated
Ordering Information:
(Also refer to the current Viking price list.)
Order Viking Microfast
®
Quick Response Fusible Element Upright Sprinkler VK328 by first adding the appropriate suffix for the
sprinkler finish and then the appropriate suffix for the temperature rating to the sprinkler base part number.
Finish Suffix: Brass = A, Chrome = F, White Polyester = M-/W, Black Polyester = M-/B and ENT = JN
Temperature Suffix: 165 °F (74 °C) = C, 205 °F (96 °C) = E, and 280 °F (138 °C)
For example, sprinkler VK328 with a 1/2” NPT thread, Brass finish and a 165 °F (74 °C) temperature rating = Part No. 13958AB
Available Finishes And Temperature Ratings:
Refer to Table 1.
Accessories:
(Also refer to the Viking website.)
Sprinkler Wrench:
Standard Wrench: Part No. 21475M/B (available since 2017)
Sprinkler Cabinets:
A. Six-head capacity: Part No. 01724A (available since 1971)
B. Twelve-head capacity: Part No. 01725A (available since 1971)
4. INSTALLATION
Refer to appropriate NFPA Installation Standards.
Replaces Form No. F_071114 Rev 20.1
(Removed bushed part numbers)
