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MV & LV SERIES ENGINEERED DRY CHEMICAL FIRE EXTINGUISHING SYSTEM
OPERATION, DESIGN, & SERVICE MANUAL
REV C
Document # DOC324
Issued: April 26, 2018
Revised: March 22, 2022
UL FILE # EX27541
Class150lbttingsshallnotbeused.
4.1.2.3 Grooved Fittings and Couplings
Grooved fittings and couplings must comply with NFPA 17 and have a minimum rated working pressure
of 500 psi (34.48 bar) at 70°F (21.1°C) based upon carbon steel pipe roll or cut grooved in accordance with
the fitting or coupling manufacturer's guidelines.
Gaskets must be compatible with Dry Chemical agent (typically EPDM having a temperature range of -30°F
to 230°F [-34°C to 110°C]). Gasket lubricant must be in accordance with manufacturer's specifications.
4.1.2.4 Pipe Reductions
Reductions in pipe sizes may be accomplished using threaded or grooved concentric reducing fittings, steel
or stainless steel concentric swage fittings, or steel or stainless steel reducing bushings. All such fittings must
comply with NFPA 17 and have a minimum rated working pressure of 500 psi (34.48 bar) at 70°F (21.1°C).
Pipe reductions can be made using machined or forged steel hex bushings. Malleable and/or cast iron bushings
are NOT to be used.
4.1.2.5 Pipe Supports and Hangers
Dry Chemical piping must be adequately supported with appropriate pipe supports and hangers to withstand
the thrust exerted during system discharge. e number of supports and hangers required depends on the
specific system piping configuration.
All supports and hangers shall comply with NFPA 17 and be used in accordance to their manufacturer's
limits and specifications and state and local building codes.
Hangers and supports must be steel. ey must adequately allow for movement or contraction occurring
from changing thermal conditions.
Hangers and supports must be designed and installed to minimize vertical and lateral sway or thrust.
Hangers and supports must be placed at every change in direction of the piping network and at every nozzle.
Additional supports shall be placed at intermediate location in between.
When intermediate hangers are of the rod type, they must be steel clad or steel clevis, of proper size, and
with a solid bar-type hanger rod to support the weight of the pipe and agent.
When grooved pipe, fittings, and couplings are used, brackets and supports must be anchored per the fitting
manufacturer's specifications. No grooved pipe length shall be left unsupported.
Cast iron supports, conduit clamps, or "C" clamps are not to be used to support pipe.
Section 4 System Installation
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