QUICK RESPONSE
CONCEALED PENDENT
SPRINKLERS
VK4651 (K4.2)
TECHNICAL DATA
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: techsvcs@vikingcorp.com
Visit the Viking website for the latest edition of this technical data page www.vikinggroupinc.com
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Form No. F_040320 21.12.02 Rev 21.3
1. DESCRIPTION
Viking Quick Response Concealed Pendent Sprinkler VK4651 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:
• K4.2 (57 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
Refer to the Approval Charts 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)
Factory tested hydrostatically to 500 psi (34.5 bar).
Thread size: 1/2” (15 mm) NPT or 15 mm BSPT
Nominal K-Factor: 4.2 U.S. (57 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 Frame: QM Brass
Deflector: Phosphor Bronze UNS-C51000
Deflector Pins: Stainless Steel UNS-S43000
Pip Cap and Insert Assembly: Copper UNS-C11000, SS UNS-S30400 and SS 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
Bulb: Glass, nominal 3 mm diameter
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.
For Light Hazard Occupancies Only
Replaces Form No. F_040320 Rev 21.2
(Updated wrench drive.)
