DuraVent DuraStack Installation - Manual (Page 26)

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SECTION G - GREASE DUCT APPLICATION (DIS ONLY)
ACCESS
Grease.Duct.installations.require.provisions.for.cleaning.the.interior.of.
the.duct...NFPA.96.clean-out.requirements.are.as.follows:
1....A.clean-out.must.be.provided.at.each.change.of.direction.except.
where.the.entire.length.of.the.duct.can.be.inspected.and.cleaned.
from.either.the.hood.or.the.discharge.end.
2....On.horizontal.duct.runs,.at.least.one.(1).20”.(508).diameter.opening.
must.be.provided..Where.the.duct.is.smaller.than.20”.(610).diam-
eter,.openings.large.enough.to.permit.cleaning.must.be.provided.at.
intervals.of.not.more.than.12’.(3.66m).
3....Openings.may.be.at.the.side.or.the.top.of.the.duct.whichever.is.more.
accessible..When.the.opening.is.on.the.side.of.the.duct,.the.lower.
edge.of.the.opening.must.be.at.least.1-1⁄2”.(38).above.the.bottom.
of.the.duct..For.Model.DIS.Grease.Duct,.this.is.accomplished.by.the.
use.of.the.Grease.Tee.(GT90).with.a.Tee.Cap.(TC).
4....On.vertical.duct.where.personnel.entry.is.possible,.access.must.be.
from.the.top.of.the.riser..Where.entry.is.not.possible,.access.must.
be.provided.at.each.floor.
NOTE: ACCESS REQUIREMENTS ARE SUBJECT TO CHANGE IN AC-
CORDANCE WITH LOCAL CODE. LOCAL AUTHORITIES SHOULD BE
CONSULTED FOR EXACT REQUIREMENTS.
USE AND INSTALLATION OF INDIVIDUAL PARTS
1.. .Duravent.Model.DIS.parts.numbering.and.parts.usage.are.discussed.
under.chimney.applications.beginning.on.page 4.of.these.installation.
instructions..
2.. .Those.parts.specific.to.grease.duct,.which.are.not.normally.used.in.
chimney.applications,.are.discussed.in.the.following.sections.
3.. .Installation.is.the.same.as.described.for.standard.application.on.page
5,.but.a.additional.bead.of.sealant.must.be.applied..See figure 2.
HORIZONTAL DRAIN LENGTH (HDL)
1.. .Horizontal.Drain.length.is.equipped.with.a.1”.(25).NPT.nipple,.which.
is.attached.to.the.inner.flue.and.extends.through.the.outer.casing.to.
provide.a.path.to.drain.grease,.condensate.or.wash.water.from.the.
duct..See.Figure 67.
2.. .A.dam.is.attached.to.the.inside.of.the.inner.flue.adjacent.to.the.nipple.
to.channel.the.effluent.to.the.drain..
3.. .The.duct.drain.is.intended.for.use.at.the.end.of.a.horizontal.run.where.
access.and.drainage.is.needed.(See.Figure 68)..
4.. .The.drain.coupling.must.be.connected.to.a.grease.trap.or.approved.
container.(supplied.by.others).
Figure 70 - Square to round adaptor
SQUARE TO ROUND ADAPTOR
1.. .When.the.hood.is.equipped.with.a.square.or.rectangular.collar,.a.
square.to.round.adaptor.is.needed.to.connect.the.round.DIS.chimney.
to.the.hood.(See.Figure 70)..
2.. .The.outside.dimensions.of.the.square.end.are.slightly.smaller.than.the.
hood.collar..It.will.fit.inside.the.collar.and.be.connected.by.welding.
the.two.parts..
Figure 67 - Horizontal Drain length
NOZZLE SECTION
1.. .The.nozzle.section.is.used.when.the.duct.is.required.to.be.equipped.
with.a.fire.suppression.system.or.washdown.is.desired...
2.. .The.nozzle.section.allows.a.spray.head.or.nipple.to.be.attached.to.
the.duct.through.a.1”.(25).NPT.coupling.attached.to.the.inner.flue.
and.when.the.chimney.section.is.in.a.vertical.orientation,.the.nozzle.
may.be.located.at.the.most.convenient.place..See.Figure 69.
3.. .Local.authorities.should.always.be.consulted.regarding.the.need.for.
fire.protection.or.washdown.systems.be.installed.so.that.the.coupling.
is.at.or.above.the.horizontal.centerline.of.the.chimney...
Figure 69 - Nozzle Section
Grease dam
Drain
Grease dam
Drain
Nozzle
Nozzle
Not UL listed
Figure 68 - Horizontal drain length typical location
Hood (by others)
Drop to hood
Up to fan
Standard 90° tee Clean-out cap
Horizontal
drain length
Plan view
NOTE:.DIAGRAMS.&.ILLUSTRATIONS.ARE.NOT.TO.SCALE.