8/16/2019 Hvac Duct Liner - Smacna

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7.12 HVAC Duct Construction Standards Metal and Flexible • Third Edition

FIGURE 711 FLEXIBLE DUCT LINER INSTALLATION

E

E

 A

 A

B

B

D

      D

      B

      C

LAPPED AND BUTTED CORNER

 ALTERNATEFOLDEDCORNER

 ALL TRANSVERSEEDGES TO BECOATED WITH

 ADHESIVE EXCEPT

MAXIMUM SPACING FOR FASTENERS. ACTUAL INTERVALS ARE APPROXIMATE.

DUCTSECTION(TYPICALLY 4 FT. (1.2 m)

THE VELOCITY RATEDSIDE OF LINER MUSTFACE THE AIR FLOW

 AIR FLOWSEE TYPICAL DUCT BRANCH ENTRY CONDITION IN FIG. 26.

DETAIL  A

UNLESS A LOWERLEVEL IS SET BYMANUFACTUREROR LISTING

 AGENCY

 *

DimensionsVelocity  *

 A

3”

(76.2) (152)

12”

B

(102)

4”

C

(152)

6”

D

0  2500 FPM

(12.7  30.5 MPS)

OR 5 FT. (1.52 m))

3” 6” 4” 6”2501  6000 FPM

(76.2) (305) (102) (152)(0  12.7 MPS)

WHEN NOSING ISPRESENT

”A” PIN ROW MAY BE OMITTED WHEN METAL NOSING ISUSED. ”E” THEN STARTS FROM THE NOSING.

METAL NOSING MUST BE USED WHEREVER LINER IS PRECEDEDBY UNLINED METAL; OTHERWISE WHEN VELOCITY EXCEEDS4000 FPM (20.3 MPS) USE METAL NOSING ON EVERY LEADING

EDGE. NOSING MAY BE FORMED ON DUCT OR BE CHANNELOR ZEE ATTACHED BY SCREWS, RIVETS OR WELDS.

INTERIOR WIDTH OF 8” (200 mm) AND LESS DOES NOT

REQUIRE PINS.

NOTE:

METAL NOSING

CHANNEL OR ZEE

C

PLACE PINS

3” (76 mm) ALONG

EACH SIDE OF ABUTTED LONGITUDINALLINER SEAM THATIS AWAY FROM ACORNER

(457)

16”

18”

(406)

E

LINER ADHERED TOTHE DUCT WITH 90%MIN. AREA COVERAGEOF ADHESIVE