Form No. F_081911 Rev 14.

1 Page  of 5

quick response
extended coverage
TECHNICAL DATA
horizontal sidewall
sprinkler vk638 (k8.0)
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
1. DESCRIPTION
Viking Quick Response Extended Coverage Horizontal Sidewall Sprinkler VK638 is a
thermosensitive spray sprinkler available in several different finishes and temperature
ratings to meet varying design requirements. The glass bulb operating element and
special deflector characteristics meet the challenges of quick response extended cov-
erage standards. The special Polyester and Polytetrafluoroethylene (PTFE) coatings
can be used in decorative applications where colors are desired. In addition, these
finishes are cULus listed as corrosion resistant as indicated in the Approval Chart.

2. LISTINGS AND APPROVALS

cULus Listed: Category VNIV
Refer to the Approval Chart and Design Criteria for cULus Listing require-
ments that must be followed.
Special Features:
3. technical data For Light Hazard Occupancies Only
Specifications:
Designed for Corridor Applications
Available since 2012.
28 Maximum Width Spacing
Maximum Working Pressure: 175 psi (12 bar)
Factory tested hydrostatically to 500 psi (34.5 bar).
Thread size: 3/4 (20 mm) NPT
Nominal K-Factor: 8.0 U.S. (115.2 metric)
Metric K-factor measurement shown is in Bar. When pressure is measured in kPa, divide the metric K-factor shown by 10.0.
Glass-bulb fluid temperature rated to -65 F (-55 C)
Overall Length: 2-3/4 (70 mm)
Covered by the following US Patent Nos: 7,854,269; 7,712,218; and 8,662,190
Material Standards:
Viking Technical Data may be found on
Sprinkler Frame: Brass UNS-C84400
Flow Shaper: Brass UNS-C23000 The Viking Corporations Web site at
Bulb: Glass, nominal 3 mm diameter http://www.vikinggroupinc.com.
Pip Cap and Insert Assembly: Copper UNS-C11000 and Stainless Steel The Web site may include a more recent
UNS-S30400 edition of this Technical Data Page.
Compression Screws: 18-8 Stainless Steel
Belleville Spring Sealing Assembly: Nickel Alloy, coated on both sides with PTFE Tape
Yoke: Bronze UNS-C51000
For PTFE Coated Sprinklers: Belleville Spring-Exposed, Screw-Nickel Plated, Pip Cap-PTFE Coated
For Polyester Coated Sprinklers: Belleville Spring-Exposed
Ordering Information: (Also refer to the current Viking price list.)
Order Sprinkler VK638 by first adding the appropriate suffix for the sprinkler finish and then the appropriate suffix for the tempera-
ture rating to the sprinkler base part number.
Finish Suffix: Brass = A, Chrome = F, White Polyester = M-/W, Black Polyester = M-/B, and Black PTFE = N
Temperature Suffix: 135 F (57 C) = A, 155 F (68 C) = B, 175 F (79 C) = D, 200 F (93 C) = E
For example, sprinkler VK638 with a Brass finish and a 155 F (68 C) temperature rating = Part No. 17375AB.
Available Finishes And Temperature Ratings: Refer to Table 1.
Accessories: (Also refer to the Sprinkler Accessories section of the Viking data book.)
Sprinkler Wrenches:
A. Standard Wrench: Part No. 10896W/B (available since 2000)
B. Wrench for coated and/or recessed sprinklers: Part No. 13655W/B (available since 2006)
A ratchet is required (not available from Viking).
Sprinkler Cabinets:
A. Six-head capacity: Part No. 01724A (available since 1971)
B. Twelve-head capacity: Part No. 01725A (available since 1971)

(Added Patent Number)

Form No. F_081911 Rev 14.1 Page  of 5

quick response
extended coverage
TECHNICAL DATA
horizontal sidewall
sprinkler vk638 (k8.0)
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

4. Installation
Refer to appropriate NFPA Installation Standards.

5. Operation
During fire conditions, the heat-sensitive liquid in the glass bulb expands, causing the bulb to shatter, releasing the yoke, pip cap,
and sealing spring assembly. Water flowing through the sprinkler orifice strikes the sprinkler flow shaper, forming a uniform spray
pattern to extinguish or control the fire.

6. inspections, tests and maintenance

Refer to NFPA 25 for Inspection, Testing and Maintenance requirements.

7. availability
Viking Sprinkler VK638 is available through a network of domestic and international distributors. See The Viking Corporation web
site for the closest distributor or contact The Viking Corporation.

8. Guarantee
For details of warranty, refer to Vikings current list price schedule or contact Viking directly.

TABLE 1: AVAILABLE SPRINKLER TEMPERATURE RATINGS AND FINISHES

Sprinkler Temperature Sprinkler Nominal Maximum Ambient
Bulb Color
Classification Temperature Rating1 Ceiling Temperature2
Ordinary 135 F (57 C) 100 F (38 C) Orange
Ordinary 155 F (68 C) 100 F (38 C) Red
Intermediate 175 F (79 C) 150 F (65 C) Yellow
Intermediate 200 F (93 C) 150 F (65 C) Green
Available Sprinkler Finishes: Brass, Chrome, White Polyester, Black Polyester, and Black PTFE
Corrosion-Resistant Coatings3: White Polyester, Black Polyester, and Black PTFE
Footnotes
1
The sprinkler temperature rating is stamped on the deflector.
2
Based on NFPA-13. Other limits may apply, depending on fire loading, sprinkler location, and other requirements of the Authority Having Jurisdiction.
Refer to specific installation standards.
3
The corrosion-resistant coatings have passed standard corrosion tests required by particular approving agencies as indicated in the Approval Chart.
These tests cannot and do not represent all possible corrosive environments. Prior to installation, verify through the end-user that the coatings are
compatible with or suitable for the proposed environment. The coatings indicated are applied to the exposed exterior surfaces only. For PTFE coated
open sprinklers only, the waterway is coated.
NOTE: The spring is exposed on sprinklers with PTFE and Polyester coatings.

Figure 1:
Sprinkler Dimensions
Form No. F_081911 Rev 14.1 Page  of 5

quick response
extended coverage
TECHNICAL DATA
horizontal sidewall
sprinkler vk638 (k8.0)
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

Maximum Water
Sprinkler Base NPT Thread Size Nominal K-Factor Overall Length
Working Pressure
Part Number1
Inches mm U.S. metric2 Inches mm
175 psi (12 Bar)
17375 3/4 20 8.0 115.2 2-3/4 70

Approval Chart
Quick Response Extended Coverage HSW Sprinkler VK638
For Light Hazard Occupancies Only.
For installation below smooth, flat, horizontal ceilings only.
Listings and Approvals4
Maximum Areas of Coverage3 Deflector-to-Ceiling
Minimum Water Supply Requirements3 (Refer also to Design Criteria below.)
(Width x Throw) Distance
cULus5 FM NYC
28 x 12 (8.5 m x 3.7 m) 34 gpm @ 18.1 psi (128.7 L/min @ 1.24 Bar) 4 to 12 (102 to 305 mm) A1X -- See Footnote 6.

28 x 14 (8.5 m x 4.3 m) 40 gpm @ 25.0 psi (151.4 L/min @ 1.73 Bar) 4 to 12 (102 to 305 mm) A1X -- See Footnote 6.

Approved Escutcheons
Approved Temperature Ratings Approved Finishes
X - Standard surface-mounted escutcheon or the Viking Microfast
A - 135 F (57 C), 155 F (68 C), 175 F 1 - Brass, Chrome, White Poly-ester7, Model F-1 Adjustable Escutcheon, or Recessed with the
(79 C),
and 200 F (93 C) Black Polyester7, and Black PTFE7 Viking Micromatic Model E-1 or E-2 Recessed Escutcheon,
or the Model G-1 Recessed Escutcheon.

Footnotes
1
Part number shown is the base part number. For complete part number, refer to current Viking price list schedule.
2
Metric K-factor measurement shown is when pressure is measured in Bar. When pressure is measured in kPa, divide the metric K-factor shown by 10.0.
3
For areas of coverage smaller than shown, use the Minimum Water Supply Requirement for the next larger area listed. Flows and pressures listed
are per sprinkler.
4
This chart shows the listings and approvals available at the time of printing. Other approvals may be in process. Check with the manufacturer for any
additional approvals.
5
Listed by Underwriters Laboratories, Inc. for use in the U.S. and Canada for Light-Hazard occupancies with smooth, flat, horizontal ceilings only.
6
Meets

New York City requirements, effective July 1, 2008.
7
cULus Listed as corrosion resistant.

DESIGN CRITERIA
(Also refer to the Approval Chart above.)
cULus Listing Requirements:
Quick Response Extended Coverage HSW Sprinkler VK638 is cULus Listed as indicated in the Approval Chart for installation in accordance with the
latest edition of NFPA 13 for extended coverage sidewall spray sprinklers:
Limited to Light Hazard occupancies with smooth, flat, horizontal ceilings only.
Locate the the deflector 4 to 12 (102 mm to 305 mm) below the ceiling. Install with the leading edge of the deflector oriented parallel to the ceiling
and with the sprinkler frame arms oriented perpendicular to the ceiling (see Figure 3). THE TOP SURFACE OF THE DEFLECTOR IS MARKED
TOP. The sprinkler must be oriented as shown in Figure 3.
Minimum distance between sprinklers is 12 ft. (3.7 m).
Minimum distance from end walls is 4 in. (102 mm).
Maximum distance from the end wall shall be no more than one-half of the allowable distance between sprinklers. The distance shall be measured
perpendicular to the wall.
The sprinkler installation and obstruction rules contained in NFPA 13 for extended coverage sidewall spray sprinklers must be followed.

IMPORTANT: Always refer to Bulletin Form No. F_091699 - Care and Handling of Sprinklers. Also refer to pages
EC1-3 for general care, installation, and maintenance information. Viking sprinklers are to be installed in ac-
cordance with the latest edition of Viking technical data, the appropriate standards of NFPA, FM Global, LPCB,
APSAD, VdS or other similar organizations, and also with the provisions of governmental codes, ordinances, and
standards, whenever applicable.
Form No. F_081911 Rev 14.1 Page  of 5

quick response
extended coverage
TECHNICAL DATA
horizontal sidewall
sprinkler vk638 (k8.0)
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

Figure 2:
Installation of Coated and/or Recessed Sprinkler VK638

Figure 3:
Correct Deflector Orientation
Form No. F_081911 Rev 14.1 Page  of 5

quick response
extended coverage
TECHNICAL DATA
horizontal sidewall
sprinkler vk638 (k8.0)
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

Figure 4:
Sprinkler VK638 Installed

(Added Patent Number)