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© 2018 | Minimax Fire Protection | 321 Industrial Park Dr. | Hastings, MI 49058 | www.minimax-fire.com
Form No. FX_062098 18.12.04 Rev 18.1
Technical Data Sheet: MX8462-MRI (K5.6) and MX8464-MRI (K8.0) Quick Response Concealed
Pendent Sprinklers
1. DESCRIPTION
Quick Response Concealed MRI Sprinklers are intended for use inside an MRI
environment, such as the MR system room. They are not intended to be used within
the bore of the MR scanner itself. This sprinkler has been independently tested
for use with a 3-Tesla MR system in accordance with ASTM F2502-15 criteria.
The results of this test demonstrate that this product is acceptable for use in an
environment with a static magnetic field of 3-Tesla or less and the highest spatial
gradient magnetic field of 330-Gauss/cm or less.
The sprinkler is pre-assembled with a threaded adapter for installation with a low-
profile cover assembly that provides up to ½” (13 mm) of vertical adjustment. The
two-piece design allows installation and testing of the sprinkler prior to installation
of the cover plate. The “push-on”, “thread-off” design of the concealed cover plate
assembly allows easy installation of the cover plate after the system has been tested
and the ceiling finish has been applied. The cover assembly can be removed and
reinstalled, allowing temporary removal of ceiling panels without taking the sprinkler
system out of service or removing the sprinkler.
2. LISTINGS AND APPROVALS
cULus Listed:
Category VNIV
* Refer the 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)
Thread size: 1/2” (15 mm) NPT or 3/4” (20 mm) NPT
Nominal K-Factor: 5.6 U.S. (80.6 metric**) or 8.0 U.S. (115.2 metric*)
Glass-bulb fluid temperature rated to -65 °F (-55 °C)
Overall Length: 2-1/4” (58 mm)
** 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.
Material Standards - Sprinkler:
Sprinkler Body: Brass UNS-C84400
Deflector: Phosphor Bronze UNS-C51000
Deflector Pins: Stainless Steel Alloy
Bulb: Glass, nominal 3 mm diameter
Pip Cap and Insert Assembly: Copper UNS-C11000 and Stainless Steel UNS-S30400
Button: Brass UNS-C36000
Screws: 18-8 Stainless Steel
Belleville Spring Sealing Assembly: Nickel Alloy, coated on both sides with Teflon Tape
Yoke: Phosphor Bronze UNS-C51000
Cover Adapter: Brass UNS-C26800
Material Standards - Cover
Cover: Copper UNS-C11000
Base: Brass UNS-C26800 or UNS-C26000
Springs: Nickel Alloy
Solder: Eutectic
Available Temperature Ratings:
Temperature
155 °F (68 °C)
175 °F (79 °C)
200 °F (93 °C)
Suffix
B
D
E
Ordering Information:
Sprinkler Assembly and Cover Plate must be ordered separately. Refer to Tables 1 and 2.
4. INSTALLATION
Refer to appropriate NFPA Installation Standards.
5. OPERATION
During fire conditions, the heat-sensitive liquid in the glass bulb expands, causing the glass to shatter, releasing the pip cap and
sealing spring assembly. Water flowing through the sprinkler orifice strikes the sprinkler deflector, forming a uniform spray pattern
to extinguish or control the fire.
