Telephone: 269-945-9501 Technical Services: 877-384-5464 Fax: 269-818-1680 Email: techsvcs@vikingcorp.com
Visit the Viking website for the latest edition of this technical data page www.vikinggroupinc.com
1.
DESCRIPTION
Viking Standard and Quick Response Concealed Pendent Sprinkler VK4621 is a
small thermosensitive, glass-bulb sprinkler designed for installation on concealed
pipe systems where the appearance of a smooth ceiling is desired. The low-profile
cover assemblies provide up to ½" (13 mm) of vertical adjustment.
Features:
•
K5.6 (80.6 metric).
•
Quick response glass bulb operating element.
•
Integral threaded adapter cup accepts push-on or thread-on cover plates.
•
Low-profile, small diameter, removeable cover plates offer almost flush
appearance upon installation and allow ease of maintenance.
•
Protective cap prevents damage during installation and finishing and keeps
errant overspray from coating internal parts.
•
Various finishes available to meet design requirements.
•
Optional Electroless Nickel PTFE (ENT) coating provides corrosion resistance
(see Approval Chart).
2.
LISTINGS AND APPROVALS
cULus Listed: Category VNIV
FM Approved: Class 2015
Also approved for use in FM Approved vacuum dry sprinkler systems with
a maximum supervisory vacuum pressure of -3 psi (-207mbar)
Refer to the Approval Charts and Design Criteria on for cULus Listing requirements
that must be followed.
3.
TECHNICAL DATA
Specifications:
Minimum Operating Pressure: 7 psi (0.5 bar)
Maximum Working Pressure: FM - 175 psi (12 bar). UL - 250 psi (17.2 bar)
Factory tested hydrostatically to 500 psi (34.5 bar).
Thread size: 1/2" NPT or BSPT
Nominal K-Factor: 5.6 U.S. (80.6 metric*)
Glass-bulb fluid temperature rated to -65 °F (-55 °C)
* Metric K-factor measurement shown is in Bar. When pressure is measured in kPa, divide the metric K-factor shown by 10.0.
Material Standards:
Sprinkler body: QM Brass or DZR Brass
Deflector: Phosphor Bronze UNS-C51000
Deflector pins: Stainless steel UNS-S43000
Pip cap: Copper UNS-C11000
Pip cap insert: stainless steel UNS-S30400
Pip cap T-hinge ring: Stainless steel UNS-S31600
Compression screw: UNS-C36000
Belleville spring sealing assembly: Nickel alloy, coated on both sides with PTFE tape
Cover adapter: Cold rolled steel JIS G3141 and carbon steel UNS-G10100 (per JIS G3141)
Shipping cap: High density polyethylene
Cover Plate Materials:
Cover plate assembly: Copper UNS-C11000 and brass UNS-C26800 or stainless steel UNS-S30400
Spring: Beryllium nickel
Solder: Eutectic
Ordering Information: Refer to Tables 1 and 2.
4.
INSTALLATION
Refer to appropriate NFPA Installation Standards and installation instructions in this document.
Form No. F_092121
Rev 01
TECHNICAL DATA
The Viking Corporation, 210 N Industrial Park Drive, Hastings MI 49058
April 2023
QUICK RESPONSE
CONCEALED PENDENT
SPRINKLER VK4621 (K5.6)
Replaces Form No. F_092121 Rev 22.1
(Replaced wrench 24339 with 23143; replaced protective cap.)
Page 1 of 8
STANDARD AND