Pacific Air Reps, inc

Round Ductwork Specification

 

 

ROUND DUCTWORK SPECIFICATION - SAMPLE

SPEC SECTION 1589?

PART I GENERAL

1.01

RELATED DOCUMENTS:

A.

Division 15 Basic Mechanical Materials and Methods Sections apply to work of this section.

1.02

DESCRIPTION OF WORK:

A.

Extent of four-ply spiral round duct and fittings will include all round duct sizes indicated on drawings and schedules, and by requirements of this section.

B.

Refer to other Division 15 sections for ductwork accessories, insulation, fans, air handlers, test, adjust and balance.

1.03

QUALITY ASSURANCE:

A.

Manufacturers qualifications: Manufacturers are limited to those with a minimum of 5-years manufacturing experience and who are dedicated to producing high quality, uniform, air tight products that are in strict accordance with all current SMACNA standards for Metal and Flexible ductwork.

1.04

CODES AND STANDARDS:

A.

SMACNA Standards: Comply with current SMACNA Duct Construction Standards for Metal and Flexible duct or local building codes, whichever is more stringent.

B.

Have copy of current SMACNA Manuals available at field office, contractor provided.

1.05

APPROVED MANUFACTURERS:

A.

PAR,inc / Spiro-fab duct systems or other approved manufacturer who meets the above qualifications for quality assurance.

1.06

SUBMITTAL:

A.

Product Data: Submit manufacturers technical product data for round and flat oval ductwork. Indicate duct and fitting gauges, configurations, dimensions of reducers, radius of elbows, and method of sealing.

1.07

DELIVERY, STORAGE AND HANDLING:

A.

Protection: Protect ductwork and fittings in such a manner as to avoid dents, scratches, and visual impairments.

B.

Minimize damage to ends and prevent dirt and moisture from entering duct.

C.

Where stored outside, duct and fittings shall be covered with waterproof material.

1.08

DUCTWORK MATERIALS:

A.

Exposed Duct: All round duct should be handled and installed as for exposed to view.

B.

Galvanized Duct: Standard round and flat oval duct and fittings shall be fabricated from New Prime Galvanized Steel (secondary and reject steel unacceptable). Steel shall be domestic with G-60 or better galvanizing in accordance with latest ASTM Standards.

C.

Stainless Steel: Where indicated, provide Stainless Steel complying with ASTM A167, Type 304 or 316 as indicated. Finish as selected.

D.

Aluminum ductwork: Where indicated, provide aluminum duct and fittings complying with ASTM B209, Alloy 3003, temper H14.

E.

Underground/underslab Ductwork: Where indicated, provide G-60 galvanized with 4x1-mil exterior, U.L. listed PVC Coated duct and fittings approved by I.C.B.O. for direct burial. Duct shall bear U.L. marking per 10-ft section.

F.

Double wall duct: Where indicated, provide double wall spiral with inners made from 24-gauge perforated spiral duct, 3/32" holes on 3/16" staggered centers for a 22% free area, with 1-inch of 1-lb density insulation and solid outer jacket, gauged for operating class. Corrugation profile recommended.

G.

Lined duct: Round duct and fittings shown or specified as "lined" will be constructed of outer pressure shell fabricated from New Prime Galvanized steel in accordance with the latest edition of SMACNA D.C.S. and gauged for the specified pressure class. Duct and fittings will be internally lined with 1" "Spiracoustic" rigid duct liner, per manufacturer's instructions.

H.

Fume Exhaust Systems: Where indicated, provide stainless steel, PVC coated as above with 4mil to inside, or as noted.

I.

Dust Collector Ductwork: Provide galvanized duct as shown, with solid welded fittings, transitions in body of fittings, pipe size branches where fitting to fitting connects, 2-times centerline radius elbows.

J.

Gauges of Metal: Ductwork gauges shall be as specified for the operating class of systems, as shown in SMACNA D.C.S.. Gauges for fittings to be as specified, or one even gauge heavier than the ductwork. Return and Exhaust systems are considered negative pressure and should be gauged accordingly. In no case will duct or fittings be allowed lighter than 26 gauge.

1.09

FITTINGS:

A.

Fittings: provide elbows that are minimum of 1-1/2 times diameter to centerline. Branch fittings to be "Shoe T" configuration with 45 degree throat entrance.

B.

Duct Sealant: Non-hardening, non-migrating, mastic or liquid elastic sealant, type applicable for fabrication/installation detail, as compounded and recommended by manufacturer specifically for sealing joints and seams in ductwork.

C.

Sealing: All seams, all fittings. Requirements for sealing are for positive and negative pressure class.

D.

Joints: Provide minimum 5" beaded slip coupling for pipe to pipe connections

E.

Gauges: Provide fittings of one even gauge heavier than shown for spiral duct in the latest edition of SMACNA D.C.S.. In no case will duct or fittings be provided lighter than 26 gauge.

1.10

FABRICATION:

A.

Fabricate round and flat oval duct in lengths that can be safely handled while minimizing the number of connections required.

B.

Fabricate in the gauges and configurations shown on drawings and in accordance with the latest edition of SMACNA D.C.S.

C.

Manufacture fittings as specified above.

D.

Reinforce oval duct and fittings at factory to comply with pressure class reinforcing requirements of equal flat dimension and pressure class as that specified for rectangular duct in latest SMACNA HVAC D.C.S.

E.

Where continuous welded fittings specified, all welds done with electric arc process, wire wheeled and prime coated.

1.11

INSTALLATION:

A.

General: Assemble and install ductwork in accordance with the latest recognized industry practices which will achieve a virtually airtight and noiseless system capable of performing each indicated service. Install each run with a minimum of joints. Align duct to be straight and true, rigidly supported with suitable ties, braces, hangers and anchors of type which will hold ducts true to shape and will prevent buckling. Hanger gauge, reinforcing and spacing as specified in latest edition of SMACNA HVAC D.C.S.

B.

Provide openings in ductwork where required to accommodate thermometers and controllers. Provide pilot tube openings where required for testing of systems.

C.

Locate ducts with a sufficient amount of space around equipment to allow normal operating and maintenance activities.

D.

Route ductwork as shown. Hold ducts close to walls, overhead construction, columns, and other structural elements of building.

E.

Underground ductwork installed as indicated in SMACNA HVAC D.C.S. for underslab duct. Provided anchors, tie-downs, and sub-slabs as indicated.

F.

During construction provide temporary closures of metal or taped polyethylene on open ductwork to prevent dust and dirt from entering ductwork system.

1.12

CLEANING:

A.

Clean duct system and force air at high velocity through duct to remove accumulated dust. Protect any equipment which may be harmed by excessive dirt with temporary filters, or bypass during cleaning.


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