![background image](http://html.mh-extra.com/html/viking/microfast-vk355/microfast-vk355_technical-data-manual_1024710001.webp)
MICROFAST
®
QUICK
RESPONSE FUSIBLE
ELEMENT CONVENTIONAL
SPRINKLER VK355 (K8.0)
TECHNICAL DATA
Page 1 of 3
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
Form No. F_071914 18.11.05 Rev 18.2.P65
1. DESCRIPTION
The Viking Microfast
®
Quick Response Fusible Element Conventional Sprinkler VK355 is a small,
thermosensitive, solder link spray sprinkler available in several different finishes, temperature
ratings, and K-Factors to meet design requirements. The special Polyester coatings can be used
in decorative applications where colors are desired.
2. LISTINGS AND APPROVALS
cULus Listed:
Category VNIV
Refer to Approval Chart 1 and Design Criteria on for cULus Listing requirements.
3. TECHNICAL DATA
Specifications:
Minimum Operating Pressure: 7 psi (0.5 bar)
Maximum Working Pressure: 175 psi (12 bar)
Factory tested hydrostatically to 500 psi (34.5 bar)
Testing: U.S.A. Patent No. 4,831,870
Thread size: 3/4” NPT, 20 mm BSP
Nominal K-Factor: 8.0 U.S. (115.2 metric**)
Overall Length: 2-5/16” (59 mm)
** Metric K-factor measurment shown is in Bar. When pressure is measured in kPa, divide the metric K-factor shown by 10.0.
Material Standards:
Frame Casting: Brass UNS-C84400
Deflector: Brass UNS-C26000
Fusible Element Assembly: Nickel Alloy
Trigger and Support: Stainless Steel UNS-S31600
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
Ordering Information:
(Also refer to the current Viking price list.)
Order Quick Response Fusible Element Conventional Sprinklers 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, and Black Polyester = M-/B
Temperature Suffix (°F/°C): 165°/74° = C, 205°/96° = E, and 280°/138° = G
For example, sprinkler VK355 with a Brass finish and a 165 °F/74 °C temperature rating = Part No. 18276AC
Available Finishes And Temperature Ratings:
Refer to Table 1
Accessories:
(Also refer to the Viking website.)
Sprinkler Wrenches:
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_071914 Rev 18.2
(Added P65 Warning.)
NOTE: As of May 2018 all logos have been
removed from the wrench boss.