Metodologías ágiles

3.1 SWAY BRACES FOR PIPING, CONDUIT AND DUCTS

A. Sway braces shall be installed on piping, conduit and HVAC ducts to preclude damage during seismic

activity. Provisions of this paragraph apply to all piping within a 5-foot line around outside of building unless buried in the ground. Piping grouped for support on trapeze-type hangers shall be braced at the same intervals as determined by the smallest diameter pipe of the group. No trapeze- type hanger shall be secured with less than two 1/2 inch bolts. Bracing rigidly attached to pipe flanges, or similar, shall not be used where is would interfere with thermal expansion of piping.

B. Sway Braces for Piping and Conduit:

1. Horizontal Runs: Provide transverse and longitudinal sway bracing at intervals as required for the pipe size and seismic zone.

2. Vertical Runs: Vertical runs of piping 1-1/2” or greater diameter shall be braced at not more than 10-foot vertical intervals. For piping smaller than 1-1/2” diameter, bracing shall be provided at no more than 4-foot spacing.

3. Anchor Rods, Angles, and Bars: Anchor rods, angles, and bars shall be bolted to either pipe clamps or pipe flanges at one end and cast-in place concrete or masonry insert of clip angles bolted to the steel structure on the other end. Rods shall be solid metal or pipe as specified below. Anchor rods, angles, and bars shall not exceed lengths given in Table III.

4. Clamps: Clamps on uninsulated pipes shall be applied directly to pipe. Insulated piping shall have clamps applied over insulation vapor barrier with high-density inserts and metal protection shields under each clamp.

5. Bolts: Bolts used for attachment of anchors to pipe and structure shall be not less than 1/2 inch diameter.

C. Sway Braces for HVAC Ducts:

SEISMIC CONTROLS FOR MEP/F/T SYSTEMS 200548-9 45 degrees or more, at the end of each duct run, and otherwise at intervals as required for duct size and seismic zone. Walls which ducts penetrate may be considered transverse braces.

2. Longitudinal Sway Bracing: Longitudinal sway bracing shall be provided at intervals as required

for duct size and seismic zone. Transverse bracing for one duct section may also act as longitudinal bracing for a duct section connected perpendicular to it, if the bracing is installed within 4 feet of the intersection, and it is sized for the larger duct.

3.2 PIPING AND CONDUIT PENETRATION REQUIREMENTS

A. All piping from 1 to 3-1/2 inches diameter shall be installed with 1" clearance on all sides and at every floor, and masonry or concrete wall penetration. A 2" clearance is required for pipe sizes larger than 3-1/2".

B. Insulated and uninsulated pipes and conduit passing through walls and partitions (except smoke and

fire walls and partitions) shall be run through not less than No. 12 gauge steel pipe sleeves finishing flush with the finished wall surfaces. Where covered pipes pass through the walls or partitions, same shall be centered in steel pipe sleeves. All sleeves or thimbles shall be independent of the pipes they enclose and centered in sleeves to insure free movement of the pipes without injury to pipe insulation, wall or other finish. Caulk around all pipes and pipe sleeves passing through walls or ceilings with untarred jute and make airtight and soundproof.

C. Insulated and uninsulated pipes and conduit passing through fire, or fire and smoke walls and partitions shall be run through rated wall sleeve assemblies sealed with Hilti CS-240 firestop sealant or approved equal UL approved sealant meeting the approval of the authority having jurisdiction and as indicated on details on drawings.

D. Pipe sleeves through outside walls shall be Schedule 40 steel pipe sleeves with 1-1/2"collar welded

to center of sleeve and cast in wall. Caulk between sleeves and pipes and make watertight.

E. Materials and equipment shall conform to the respective specifications and other requirements specified below:

3.3 SPREADERS

A. Provide spreaders between racked or adjacent piping runs to prevent contact during seismic activity whenever pipe or insulated pipe surfaces are less than 4 inches apart or four times the maximum displacement due to seismic force. Spreaders to be applied at same interval as sway braces. Spreaders shall be applied to surface of bare or insulated hot pipe and over insulation utilizing high- density inserts and pipe protection shields where vapor-barrier-type insulation is employed.

3.4 FLEXIBLE COUPLINGS OR JOINTS

A. Building Piping: Flexible couplings or joints in building piping shall be provided in the following locations on pipe risers:

1. Within 24 inches of the top and bottom of all risers. This requirement may be deleted in risers

less than 3 ft. in length, and in risers 3 to 7 ft. in length, one flexible coupling is adequate. B. Underground Piping: All underground piping and 4-inch or larger conduit, except heat distribution

system, shall have flexible couplings installed adjacent to building. Additional flexible couplings shall be provided as follows:

1. On each side of the joints of demarcation between soils having widely differing degrees of consolidation.

2. At all points that can be considered to act as anchors.

3. On every branch of a tee and each side of an elbow.

3.5 ANCHOR BOLTS

A. All floor or pad mounted equipment required by any Section of these specifications shall use cast-in-

place or female wedge type anchor bolts. Anchor bolts must conform to ASTM A 307. Female wedge anchors shall have an evaluation report number from ICBA Evaluation Service. Anchor bolts shall have an embedded straight length equal to at least twelve times nominal diameter of the bolt. If the size and number of the anchor bolts are not shown on the drawings, then anchor bolts shall conform to the applicable codes and standards for the various equipment weights or the manufacturer's installation recommendations, whichever is the most stringent.

SEISMIC CONTROLS FOR MEP/F/T SYSTEMS 200548-10

A. Provide for all items supported from overhead floor or roof structures with the following

requirements:

B. Braces shall consist of angles, rods, bars, or pipes secured at both ends with not less than 1/2 inch

bolts. Braces shall conform to all applicable codes and standards. Bracing shall be provided in two planes of directions, 90 degrees apart, for each item of equipment. Sufficient braces shall be provided for equipment to resist a horizontal force equal to 50 percent of the weight of equipment without exceeding safe working stress of bracing components. Details of all equipment bracing shall be submitted for approval.

C. In lieu of bracing with vertical supports, these items may be supported with hangers inclined at 45

degrees directed up and radially away from equipment and oriented symmetrically in 90 degree intervals on the horizontal plane, bisecting the angles of each corner of the equipment, provided that supporting members are properly sized to support operating weight of equipment when hangers are included at a 45 degree angle.

3.7 CEILING MOUNTED AIR TERMINALS OR SERVICES INSTALLED IN LAY-IN CEILINGS

A. Positively attach to the ceiling suspension main runners or to cross runners with the same carrying capacity as the main runners.

B. Terminals or services weighing not more than 56 pounds, in addition to the above, shall have two No. 12 gauge hangers connected from the terminal or service or to the structure above. These wires may be slack.

C. Terminals or services weighing more than 56 pounds shall be supported directly from the structure above by approved hangers.

3.8 MISCELLANEOUS EQUIPMENT

A. The following specific items of equipment to be furnished under this contract shall be constructed and assembled so as to be capable of withstanding the horizontal equivalent static force of 0.11 times the operating weight of the equipment, at vertical center of gravity of the equipment without causing permanent deformation, dislocations, separation of components, or other damage, which would render the equipment inoperative for significant periods of time following an earthquake.

1. Air Handling Units

2. Free Standing Electric Motors

3.9 INSTALLATION

A. Install and anchor seismic-control products according to manufacturer's written instructions and authorities having jurisdiction.

B. Anchor interior mounts, isolators, hangers, and snubbers to vibration isolation bases. Bolt isolator baseplates to structural floors as required by authorities having jurisdiction.

C. Anchor exterior mounts, isolators, hangers, and snubbers to vibration isolation bases. Bolt isolator baseplates to structural supports as required by authorities having jurisdiction.

D. Fill concrete inertia bases, after installing base frame, with 3000-psig concrete, and trowel to a smooth, hard finish.

E. Install pipe connectors at connections for equipment supported on vibration isolators.

F. Install cables to prevent excessive seismic motion and so arranged that they do not engage during normal operation.

3.10FLOOR MOUNTED EQUIPMENT SUPPORT

A. Vibration Isolation Bases: Mount equipment on structural-steel bases or concrete inertia bases.

B. Snubbers: Install the required number of seismic snubbers on each spring-mounted piece of

equipment. Locate snubbers as close as possible to the vibration isolators and bolt to supporting structure.

3.11ADJUSTING AND CLEANING

A. Adjust limit stops on restrained spring isolators to mount equipment at normal operating height. After equipment installation is complete, adjust limit stops so they are out of contact during normal

SEISMIC CONTROLS FOR MEP/F/T SYSTEMS 200548-11 operations.

B. Adjust thrust restraints for a maximum of 1/4 inchof movement at start and stop.

3.12SPECIAL INSPECTION

A. Special Inspector: Employ a factory trained representative during construction to observe the work

specified and to ensure that it conforms to the Contract documents. Factory trained representative shall be a qualified person who shall demonstrate competence and specialized experience, to the satisfaction of the engineer of record, for inspection of the seismic protection of mechanical and electrical equipment.

B. Inspection Requirements: The factory trained representative shall periodically inspect the following systems to verify conformance with the contract documents and the local code:

1. Installation of piping systems intended to carry flammable, combustible or highly toxic contents

and their associated mechanical units in structures assigned to Seismic Design Category C, D, E or F.

2. Installation of HVAC ductwork that will contain hazardous materials in structures assigned to Seismic Design Category C, D, E or F.

3. Installation of vibration isolation systems in structures assigned to Seismic Design Category C,

D, E or F where a nominal clearance of 0.25 inches or less between the equipment support frame and restraint is required.

C. Inspection Reports: Ensure that the inspection report is furnished from the special inspector to the engineer of record. At the end of the work, ensure that a final, signed report is submitted by the special inspector, stating whether the work requiring special inspection was, to the best of the special inspector’s knowledge, in conformance with the Contract documents.

D. Discrepancies: Discrepancies shall be brought to the immediate attention of the Contractor for correction, and then, if uncorrected, to the architect and engineer of record.