M&G DuraVent DuraStack User Manual

Installation Instructions

A Modular Double-Wall Positive Pressure
Chimney System. Factory Built for Boiler
Breeching, Engine Exhaust, and Chimney
Stack. Grease Duct (DIS only)

DuraStack

®

DIS/DAS

A MAJOR CAUSE OF VENT RELATED FIRES IS FAILURE

TO MAINTAIN REQUIRED CLEARANCES (AIR SPACES) TO

COMBUSTIBLE MATERIALS. IT IS OF THE UTMOST IMPORTANCE

THAT POLYPRO® BE INSTALLED ONLY IN ACCORDANCE WITH

THESE INSTRUCTIONS.

WARNING

CARBON MONOXIDE POISONING
HAZARD. Failure to follow the steps
outlined below for each appliance
connected to the venting system being
placed into operation could result in
carbon monoxide poisoning or death.

WARNING

Risk of carbon monoxide poisoning
or re due to joint separation or pipe
breakage.

• Examine all components for possible

shipping damage prior to installation

• Proper joint construction is essential

for a safe installation. Follow these
instructions exactly as written.

• This venting system must be free to

expand and contract.

• This venting system must be supported

in accordance with these instructions.

• Check for proper joint construction

when joining pipe to ttings.

• Check for unrestricted vent movement

through, walls, ceilings, and roof
penetrations.

• Dierent manufacturers have dierent

joint systems and adhesives. Do not mix
pipe, ttings or joining methods from
dierent manufacturers.

IMPORTANT

Read through all of these instructions
before beginning your installation. Failure
to install this product as described in these
instructions will void the manufacturer’s
warranty, may create a re or other safety
hazard, and may aect your homeowner’s
insurance and safety listing of your appliance.

Keep these instructions for future
reference.

Dear Customer, Installer, or End User:

We welcome any comments regarding
matters pertaining to our DuraVent products.
We welcome any ideas, input or complaints
to help improve our product oering. Send
your emails to:
[e-mail]

If you are searching for tech support or
product information, please phone us at
800-835-4429.
Or email us at:
[e-mail]

Double Wall Construction Positive Pressure Chimney System

For the most up-to-date installation instructions, see www.duravent.com

CONTENTS

INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . 4

TESTING/LISTING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . 4

SECT ION A: GENERAL INFORMATION . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . 4

SECT ION B: TEES, EL BOWS, INCRE ASERS. . . . . . . . . . . . . . . . . . .. . . . . . . . . .. . . 12

SECTION C: STRUCTURAL SUPPORT AND GUIDING. . . . . . .. . . . . . . . . . . . .16

SECTION D: ROOF AND WALL PENETRATIONS. . . . . . . . . . . . .. . . . . . . . . .. . . .22

SECTION E: TERMINATIONS, STARTING ADAPTORS, DRAIN LENGTH AND

RELIEF VALVE . . . .. . . . .. . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . .24

SECT ION F: THERMAL EXPANSION. . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

SECTION G: GREASE DUCT APPLICATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

PRODUCT REFERENCE INFORMATION. . . . . . . .. . . . . . . . . . . . . . . . . . . . . .. . . .38

SECTION H: MARKINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

WARRANTY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40

DuraStack

®

DIS/DAS

3

INTRODUCTION

DuraVent Model DuraStack DIS or DAS
Chimney are cylindrical, prefabricated,
modular venting systems incorporating a
unique extended inner ange designed for
both quick assembly and pressure sealing
capability. Model DIS incorporates a 2” of
mineral ber insulation while DAS is air
insulated. The circular cross section and high
quality stainless steel inner ue construction
provide for a system with high strength-to­weight ratio and low friction losses.

TESTING / LISTING INFORMATION

DuraVent model DIS and DAS venting
systems are listed with Intertek Testing
Services (ETL) to UL/ULC standards:
U.S.A.

• UL-103

- 60 in. Positive Pressure Chimney

- Building Heating Appliance Chimney

- 1400°F Chimney

• UL-1978 Grease Duct (DIS only)
CANADA

• ULC/ORD C959

- 540°C (1000°F)

- 760°C (1400°F)

• ULC S604

Models DuraStack DIS and DAS are code
compliant when installed as per the
Installation Instructions with : NFPA211;
NFPA31; NFPA37; NFPA96 and CSA-B149

When installed in accordance with it’s
installation, Models DuraStack DIS and DAS
comply with the following codes:

- NFPA (National Fire Protection Association)

- SBCCI (Southern Building Code
Congress International)

- ICBO (International Conference of
Building Ocials)

- BOCA (Building Officials and Code Administrators)

- ICC (International Code Congress)

4

SECTION A  GENERAL INFORMATION

These instructions comprise both general
guidelines and special requirements for all
parts in the product line. Before specifying a
design or beginning an installation please
carefully review these instructions.

IMPORTANT

Chimney Cleaning: This applies to cleaning
other than standard natural gas chimney
applications where minimal maintenance is
necessary. Keep your chimney clean. Access
should be provided for the inspection and
cleaning of all sections of the chimney. Have
your chimney cleaned by qualied chimney
sweep. It is recommended to use a nylon
chimney brush of the correct size. Do not
use a brush that will scratch the stainless
steel interior of the chimney.

FEATURES

Models DIS and DAS are prefabricated
modular venting systems design for industrial
and commercial applications. It has a
unique extended inner ange for both quick
assembly and pressure sealing capability. It
is a double wall construction with 2” of
mineral ber insulation for DIS and 2” air
space for model DAS. The inner ue is made
of high quality stainless steel plasma welded.

APPLICATION
UL 103 Building Heating Appliance
Chimney Listing:

Under this category, models DIS and DAS
have been determined suitable for venting
ue gases at temperatures not exceeding
538°C (1000°F) under continuous operating
conditions from gas, liquid, oil or solid fuel
red appliances. Also complies with
operation (less than one hour) at
temperatures not exceeding 740°C (1400°F)
and brief operation (maximum 10 minutes) at
temperatures not exceeding 906°C (1700°F).
Building Heating Appliance Chimneys
are suitable for use with Building Heating

Appliances and Low Heat Appliances as
described in the Chimney Selection Chart of
National Fire Protection Association (NFPA)
Standard NO. 211.

UL 103 1400°F Chimney Listing:

Under this category, models DIS and DAS
have been determined suitable for venting
ue gases at temperatures not exceeding
760°C (1400°F) under continuous operating
conditions from gas, liquid, oil or solid
fuel red appliances. Also complies with
brief operation (maximum 10 minutes) at
temperatures not exceeding 906°C (1700°F).
As such, it is suitable for use with ovens
and furnaces as described in the Chimney
Selection Chart of NFPA No. 211, in addition
to other applications.

UL 103 Positive Pressure Listing:

Under this category, models DIS and DAS have
been determined suitable for use at a maximum
of 60 inch water column internal pressure.

UL 2561 1400°F Chimney Listing

SURROUNDINGS / ENCLOSURE

DuraVent models DIS and DAS chimney are
primarily intended to be used in re resistive
noncombustible surroundings or installed
unenclosed. They are not intended for use in
one or two family residences.

CAUTION

Do not enclose this chimney in a chase
or passageway of ordinary wood or other
combustible material

Where the chimney extends through any
zone of a building (outside that in which the
heating appliance connected to it is located),
it shall be provided with an enclosure having
a re resistance rating equal to or greater
than that of the oor, wall or roof assemblies
through which it passes.

DuraVent models DIS and DIS chimney
may penetrate a combustible oor, wall
or roof using the appropriate parts and
openings sizes. See section D “Roof & Wall
Penetration” for more details.

ULC C959 540°C and 760°C Industrial
Chimneys Listing:

Under this category, models DIS and DAS
have been determined suitable for venting
ue gases at temperatures not exceeding
760°C (1400°F) under continuous operating
conditions from gas, liquid, oil or solid
fuel red appliances. Also complies with
brief operation (maximum 10 minutes) at
temperatures not exceeding 980°C (1800°F).

UL 1978 Grease Ducts Listing (DIS only):

DuraVent model DIS chimney is tested in
accordance with UL 1978 Standard and
approved for Grease Duct applications when
installed in accordance with these installation
instructions and National Fire Protection
Association standard “NFPA 96, Standard for
Ventilation Control and Fire Protection of
Commercial Cooking Operations”.

Where, according to local code, no chase
enclosure is necessary, models DIS and DAS
chimney may be placed adjacent to walls of
combustible construction at the clearance
specied on each chimney section and
in the individual listing; see “CLEARANCES”.
Contact local building or re ocials about
restrictions and installation inspection
requirements in your area.

Grease Ducts (DIS Only)

1. Model DIS grease ducts are primarily

intended for installation in noncombustible
surroundings or in unenclosed installations.

2. Where model DIS grease ducts are installed
in an open room and an enclosure is not
required, the minimum clearance to adjacent
combustible walls shall be as shown in this
section (see “CLEARANCES”). The ducting
may be located in a corner formed by two

5

walls of combustible construction, if the
conditions above are met.

3. Other interior installations in all buildings
should be as follows:
a) Where a grease duct penetrates a wall or
ceiling rated for re resistance, it should be
enclosed with a continuous non-combustible
enclosure extending from the lowest re­rated ceiling or oor above the hood, through
any concealed space, to or through the
roof so as to maintain the integrity of the
re separations required by the applicable
building code provisions. The enclosure shall
be sealed around the duct at the point of
penetration of the lowest re-rated ceiling or
oor above the hood, in order to maintain the
re resistance rating of the enclosure
and shall be extended to the exterior of
the building through weather-protected
openings.
b) A grease duct penetrating a ceiling, oor
or wall which does not have a re resistance
rating does not require to be enclosed, if
the clearances to combustibles are at the
correct minimum for unenclosed installations.
c) Where model DIS grease ducts extend
through any story of a building above the oor
on which the connected appliances are
located, they shall be enclosed in the upper
stories with walls having a re resistance rating
of not less than one hour for buildings of two
or three stories. If the building is four stories
or more, the enclosure wall shall have a re
resistance rating of not less than two hours.

4. Combustible roofs or roof-ceiling
assemblies may be penetrated as described
in Section D – Roof and wall penetrations.

SYSTEM SIZING

IMPORTANT

Do not enclose with combustible materials.

Refer to NFPA 96, “ Standard For
Ventilation Control And Fire Protection
Of Commercial Cooking Operations”, for

installation and clearances of re-rated
enclosures and denitions.

Complete system sizing and capacity
information maybe obtained from the
“Chimney, Gas Vent, and Fireplace Systems”
chapter of the ASHRAE Handbook (go to
www.ashrae.org for more information). In
spite of these general sizing guidelines, it is
most important that the heating appliance,
engine or turbine manufacturer’s installation
instructions are followed. Not following the
equipment manufacturer’s instructions may
result in inadequate chimney performance
and/or a violation of the equipment
manufacturer’s installation requirements.

PART NUMBERS

These instructions identify major model DIS /
DAS parts by name and part number.

Table 1

Part Numbers

Example Model Dia. Part Material

DIS 36” length with
inside diameter 14”
made of ss316 inner
ue and ss304 outer
casing.

DAS 30° elbow with
inside diameter 22”
made of ss304 inner
ue and galvalume
outer casing.

DIS wall support for
8” diameter chimney
made of galvalume.

IMPORTANT

Use only factory-supplied components.
Failure to do so will void the certication
and the warranty of the chimney system.

DIS 14 L36 BC

DAS 22 E30 CE

DIS 8 WS E

6

EFFECTIVE LENGTH

When assembling two parts together, the
joint will overlap 5/8”. So eective length is
nominal length minus 5/8”.

Effective Length

Example Material

L36 35 /"

Table 3

DIS Minimum Openings

Model Roof / Floor (C) Wall (C)

Ø5" - Ø10" Inside Ø + 8" Inside Ø + 8"

Ø12" - Ø36" Inside Ø + 8" Not Listed

L24 23 ⁄"

L18 17 /"

L12 11 /"

CLEARANCES
DIS

Minimum air space clearance to combustible
construction to model DIS Chimney is 1”.
For non-combustible construction, maintain
clearances as required for installation, access
for inspection or per local code.

DAS

Minimum air space clearance to combustible
construction to DAS chimney is 4”.

See Table 2.

Table 2

Clearances

Model B.H.A Chimney 1400°F Chimney

DIS 1" 1"

DAS 4" 4"

OPENING THROUGH COMBUSTIBLE
CONSTRUCTION

The following table serves to identify the
minimum opening required when installing a
chimney through a oor, wall or roof made of
combustible material. See Table 3 and Figure 1.

Table 4

DAS Minimum Openings

Model Roof / Floor (C) Wall (C)

Ø5" - Ø10" Inside Ø + 12" Inside Ø + 12"

Ø12" - Ø36" Inside Ø + 12" Not Listed

Chimney Outside
Diameter

Chimney Inside
Diameter

2" Insulation

Clearance Opening

A
B
C

WARNING

DO NOT INSTALL ANY TYPE OF
INSULATION IN THE REQUIRED
CLEARANCE SPACES SURROUNDING
THE CHIMNEY.

Openings - Minimum
opening required when
installing a chimney through

a oor, wall or roof made of

combustible material.

Figure 1

7

CHIMNEY AND FITTING JOINT ASSEMBLY

All components have a male and female end.
The installation orientation is indicated on
the labeling of each chimney section with an
arrow. The arrow indicates the direction of
the ow. Clean all inner and outer surfaces
of the male and female ends with an
appropriate organic solvent, such as acetone,
Mek, or other commercial degreaser.

1. Apply a bead of S-650 sealant about 1/8”
thick around the male end of chimney and
for Grease duct application, add a bead of
S-2000 sealant at the edge of the female
chimney (see Figure 2). See Table 5 for
approved sealants.

2. Insert the female end, of another section
of chimney, over male end with sealant (see
Figure 3).

3. Insert the assembly band (see Figure

4) around the joint of the two sections

assembled in Step 2. A small bead of S-650 can
be applied on the inner groove of the band
prior to installation for better leak tightness.

4. Using a phillips screwdriver, connect the
two ends of the band as shown in Figure 5.

5. Where the chimney is installed outside, an
exterior sealant S-375 must be applied at the
upper joint of the band and the outer casing,
see Figure 5.

Figure 3

Figure 4

Grease Duct Application: Add a

bead of S-2000 sealant at the
edge of the female end.

8

Apply S-375 sealant here for exterior installation.

Figure 5

Add S-650 sealant here.

Figure 2

Table 5

Sealant Usage

Interior Installation

Sealant

Application

Joints DuraVent S-650 Red 650°F

Inner Flue DuraVent S-2000 White 2000°F

Exterior Installation

Sealant

Application

Joints DuraVent S -650 Red 650°F

Outer Band DuraVent S-375 Gray 375°F

Supplier Model Color

Supplier Model Color

Max.

Temp.

Max.

Temp.

CAUTION

DO NOT ALLOW SCREWS TO PENETRATE
THE INNER FLUE. THIS CAN CAUSE
CORROSION, GAS LEAKAGE OR EXPANSION
FAILURE. NEVER USE SCREWS THROUGH
THE OUTER CASING OF AN ADJUSTABLE
LENGTH OR EXPANSION JOINT. OBSERVE
ADEQUATE SAFETY MEASURES WHEN
USING A DEGREASER.

Table 6

Maximum Chimney Heights and Support Method for Model DIS and DAS

Anchor Plate Anchor Plate Ventilated (APV) Wall Support (WS)

Inside Diameter

5 147 133 133 147 61 105

6 128 116 116 128 53 92

8 103 93 93 103 43 74

10 86 78 78 86 35 61

12 73 66 66 73 30 53

14 64 58 58 64 27 46

16 57 52 52 57 24 41

18 53 48 48 53 22 38

20 48 43 43 48 20 34

22 44 40 40 44 18 31

24 37 34 34 37 15 27

26 35 32 32 35 14 25

28 33 30 30 33 13 23

30 31 28 28 31 13 22

32 29 26 26 29 12 21

34 27 25 25 27 11 20

36 26 23 23 26 11 18

Building Metal

Frame

Building Metal

Frame

Building Wood

Frame

Building Metal

Frame

Building Wood

Tee (T)

Frame

9

SUPPORT METHODS AND HEIGHT LIMITS

1. Several support and guiding methods are

used to anchor a chimney against upward,
downward and angular displacement.

2. These supports and guides used with
thermal expansion devices, prevent bending
stresses on the chimney elbows and joints.

3. Supports and guiding methods and
installation are described in Section
C. Certain limitations apply for proper
installation of supports and guides. See

Tables 6 and 7.

See Dim. "H" Figure 7

and Chimney Guying and
Bracing in this section

MVS

Maximum
Height - See
Table 6

MVS

Termination

Storm Collar

Roof Support

Wall Guide

Floor Guide

Table 7

Support and Guide Spacing for Model

DIS and DAS (dimensions in feet)

Inside Diameter
(in.)

5 10 8 10 12

6 10 8 10 12

8 10 8 10 12

10 10 8 10 12

12 10 8 10 12

14 10 8 10 12

16 10 8 10 12

18 10 8 10 12

20 10 8 10 12

22 10 8 10 12

24 10 8 10 12

26 10 8 10 12

28 10 8 10 12

30 10 8 10 12

32 10 8 10 12

34 10 8 10 12

36 10 8 10 12

MVS*

Interior Exterior

H** MHS***

MVS

Wall Support

Figure 6

IMPORTANT

“MVS ” dimension see Table 7 for
Maximum Vertical Spacing between two
guides or a support and a guide.

IMPORTANT

When the maximum height from
Table 6 is exceeded, resupport using
another support and expansion joint.

10

* MVS: Maximum Vertical Spacing between two guides or a
support and a guide in a vertical position.
** H: Maximum freestanding Height above the roof.
*** MHS: Maximum Horizontal Spacing between two guides or a
support and a guide is 12 feet.

THERMAL EXPANSION

Good installation practice requires that
any length of exhaust system between two
xed points subject to more than 1/4 inch
expansion must have an Adjustable Length
(LA) or Bellows Joint (LB) to compensate
for expansion. Models DIS and DAS will
expand approximately 1 inch for every 100°F
temperature rise per 100 feet of chimney.
To accommodate chimney movements, any
wall guide or oor guide must be located

away from the locking band. It is essential
that these parts be properly installed and
provided with adequate support and
guidance to prevent binding or excessive
bending forces. (See detailed installation

information contained on page 27,
Thermal Expansion).

CHIMNEY WEIGHT

Chimney weight is given in pounds per foot
of chimney for each diameter. It is important
to know the weight of the chimney section
for chimney support or guiding. Chimney
weight (Table 8) along with maximum
chimney height (Table 6) are necessary to
calculate the proper anchor strength needed
with wall supports (WS), Anchor Plate (AP)
supports and Suspension Bands (SB).

Table 8

CHIMNEY GUYING AND BRACING

1. Proper guying and bracing is essential

for part of the chimney that extends above
the roof or parapet wall. The chimney at this
point is subject to wind conditions and needs
special attention for proper stabilization.

2. If the stack above the roof does not exceed
dimension H, no special guying or bracing
is required. However, to protect the ashing
from lateral movement, a guide must be
installed at the roof level. See Figure 7).

3. For stack height above the roof that needs
guying or bracing, a support, a small length
and a expansion length must be installed
near the roof level to absorb the thermal
expansion and minimise this eect on the
guy wires or brace.

Chimney Weight in lb/ft

Inside Diameter Model DIS Model DAS

5 7 4

6 8 5

8 10 6

10 12 8

12 14 9

14 16 10

16 18 12

18 20 13

20 22 14

22 24 15

24 28 19

26 30 20

28 32 21

30 34 23

32 36 24

34 38 25

36 40 27

Example: Model DIS, 6” diameter section of 25 feet in length from
table 8, weight in lb/ft = 8. Total weight 8 x 25 = 200 lbs

H*

Guide

Maximum
Height
See Table 6

Support

No Guying or Bracing
Required

Figure 7

IMPORTANT

If Dimension “H” exceeds the value in table
7, use bracing or cable guying to stabilize
chimney section above the roof. See Notes

3, 4, 5 and Figure 8.

11

H

Guy Cable * tensioners
and roof anchors * (by

others)

See Table 7 for "H" dimensions

Brace

Support

Expansion

Length

Guide

Support

5' Max

Maximum
Height

- See
Table 6

Figure 8

IMPORTANT

Cables and roof anchors designed for 30 lb.
per sq. ft. force on chimney projected area.

feet from any adjacent ridge, wall or parapet,
the chimney shall terminate at minimum of 3
feet above the ridge, wall, or parapet.

3. Where chimney terminates at more than 10

H

feet from ridge, wall, or parapet, a minimum
height of 2 feet shall be required above the
ridge wall or parapet.

MULTIENGINE EXHAUST SYSTEMS

A common exhaust system for multiple
engine or turbine installations is generally
not recommended. A separate exhaust
system should be provided for each engine
or turbine. Check with your engine or turbine
manufacturer prior to common exhaust
system design. Exhaust gas from operating
units tends to ow to non-operating units
where condensation may form.

IMPORTANT

Water in engine or turbines at start-up
may cause damage. In general, a separate
exhaust system should be provided for
each engine or turbine.

SECTION B TEES, ELBOWS, INCREASERS

4. When using guy wire, the cable must

be slightly slack or loose to allow thermal
expansion.

5. When using rigid bracing, the maximum
vertical height between supports must
be reduced to 5’ to compensate thermal
expansion.

TERMINATION HEIGHT

Chimneys and vents shall terminate above
the roof level in accordance with the
following requirements:

1. Five feet above the roof level or any
adjacent at roof, wall parapet or air intakes,
and/or in accordance with the following
NFPA 211 requirements.

2. Where chimney terminates at less than 10

12

90° TEE (T90)

1. Generally used to connect the horizontal

length from the appliance to the vertical
length when clean-outs access or drain is
required.

2. 90° should not be used for changing ow
direction in diesel or turbine exhaust.

3. For supporting the tee, the preferred
location is above the tee (see Figure 9).

4. If it is not possible to suspend the tee, it
may be supported from the base (see Figure

10). When this is necessary, a short length
should be installed between the tee and the
tee cap or Drain-Tee Cap for a good clean-out
or inspection access.

IMPORTANT

If more than 1/4” of thermal expansion is
expected between a stationary point and
the tee, the use of an expansion length
and a two axis support is recommended
to minimize bending moments on the tee
(see Figure 11 and Table 9).

Table 9

Maximum Allowable Length Between Two

Fixed Points w/o Expansion Length

Gas Temperature Rise Maximum Length Expansion

200°F 12'0'' 0.25"

300°F 8'0'' 0.25"

400°F 6'0'' 0.25"

500°F 5'0'' 0.25"

600°F 4'0'' 0.25"

700°F 3'6'' 0.25"

800°F 3'0'' 0.25"

900°F 2'6'' 0.25"

1000°F 2'0'' 0.25"

Note: 60°F - 70°F ambient T°

45° TEE T45

1. For systems where ow resistance must

be minimized like engine or turbine exhaust.
The use of a 45° tee is suggested. It can
be combined with a 45° elbow to make a
smooth 90° turn (See Figure 12). To support
this tee, use similar method as a 90° tee.

2. When using 45° tee to connect multiple
appliances together, thermal expansion must
be considered. Thus prepared to prevent
bending moments on the tee, an expansion
length must be installed between the tees
(See Figure 13).

Stationary
Support

Suspension

Band

Expansion

Length

Stationary
Support

More than ¼" of expected
thermal expansion between two

stationary points

Wall

Support

Tee

Tee Cap or
Drain Tee Cap

Figure 9

Lengths

Tee

Wall

Support

Short Length

Tee Cap or
Drain Tee Cap

Figure 10

Figure 11

Figure 12

13