646.03 Construction Requirements.
645-F Abandon inch {mm} Existing Sanitary Sewer – per linear foot {meter} 645-G ___ inch {mm} Sanitary Sewer Lateral Cleanout – per each 645-H ___ inch {mm} Manhole - per each 645-I ___ inch {mm} Manhole Unit - per each 645-J Manhole Cone Reset – per each 645-K Manhole Frame and Cover Reset – per each 645-L ___ inch {mm} **** Manhol e Drop Connection – per linear foot {meter} 645-M Connection to Existing Manhole – per each 645-N Abandon Existing Manhole – per each 645-O ___ inch {mm} Air and Vacuum Valve Assembly – per each 645-P Sanitary Sewer Lift Station – per each * Show Type of Pipe: Ductile Iron ( DI), Polyvinyl Chloride ( PVC), High Density Polyethylene (HDPE ), High Performance Polypropylene (PP) ** Designate One Type: Gravity or Force Main *** Designate Restrained Joint if Required **** Show Type: Ductile Iron ( DI); Polyvin yl Chloride ( PVC) NATURAL GAS LINE
646.01 Description.
This Section shall cover the work of the following • Furnishing and installing new gas mains and valves; • Removing , relaying, and resetting existing gas mains and valves; • Constructing connections to existing gas mains.
646.02 Materials.
Materials furnished for use shall conform to the requirements of Section 861 and other appropriate Sections of Division 800, Materials.
646.03 Construction Requirements.
a.General .
1.Gas Pipe . Pipe shall be laid or relaid in the presence of the Engineer. Pipe shall not be covered until allowed by the Engineer. Pipe designated to be relaid that is damaged or rendered unfit for use through negligence or improper handling shall be replaced by the Contractor without additional compensation. All new pipes shall be handled in such a manner as to prevent damage to the pipe and pipe lining. The interior of all pipes, valves, and fittings shall be free from dirt and debris. All material sha ll be stored in the appropriate manner to protect the materials from damage by freezing and subsequent handling. The construction methods employed in the adjustment, relocation, and placement of the gas lines shall be in accordance with the current codes a nd practices of the Utility Company involved. The work shall conform to the applicable requirements of the US Department of Transportation, Transportation of Natural and other Gas by Pipelines, Minimum Safety Standards. Notification to the line locators to locate the other utilities in the construction area shall be made at least 48 hours prior to performing work. Work required for the adjustments of a gas main and service line shall be performed by the Contractor in such a manner that shall limit interrupt ion of the service for a minimum period of time. Notice shall be made by the Contractor to the Customers affected by the service interruption at least four hours but not more than 72 hours prior to service interruption. When installing non -metallic gas pip e, the Contractor shall install a detectable tape or locating wire on the pipe or provide other suitable means approved by the Engineer to allow for location by electronic detection devices. Valves and other controls on the existing gas system shall not be operated for any purpose by the Contractor without approval and representation by the Utility.
646.03 Construction Requirements.
Welding of steel pipe shall be in accordance with ASME B31.8 or API 1104. Each welder shall be certified for the type work specified. Certificates of welders performing the work shall be furnished to the Engineer prior to beginning the work. Test pieces cut from the work being performed shall be provided to the Engineer when required. Each section of the gas distribution system shall be thoroughly cleaned with compressed air to remove all dirt and foreign matter. Taps shall be provided at all remote points. Once all lines have been completely and thoroughly purged, the taps shall be tightly sealed with steel plugs or by welding. Cathodic protection shall be provid ed as described in the project plans and specifications.
2.Valves . All valves shall close when the nut is turned clockwise. All valves shall have a non -rising stem and extension matching the valve stem to the finished grade. All valves shall be plumb and shall be set and jointed to the new pipe as specified for laying pipe. Valve flanges shall be as specified for fittings. Valve boxes shall be plumb and centered over the wrench nut of the valve with the box cover flush with the finished pavement or unpave d area. Valve boxes subject to traffic loading shall be set on brick or concrete to prevent box from bearing against the valve or piping. The word Gas shall be cast into the cover of the valve box.
3.Valve Box Reset A valve box shall not be reset until ap proved by the Engineer. The box shall be adjusted carefully to make sure that the top is at the designated location and elevation. Backfill shall be tamped around each box located in the pavement area to the required density of the adjacent material. An y box or accessories lost or rendered unfit for re -use due to negligence or improper handling by the Contractor shall be replaced in kind without additional compensation.
4.Line Stoppers. All line stoppers shall be installed at the locations designated to retain the contents of existing pipe outside the construction area along with preventing contamination of the existing pipeline system. Line stopper equipment shall be installed as a manuf actured package unit and pressure rated to safely cease the flow of the contents of the existing main. The line stopper procedure shall be performed by those specialized in those operations. Line stopper equipment shall be manufactured and operated by T. D. Williamson Inc., Mueller Co. or Engineer approved equal. Vendors shall have a minimum of 10 years of successful experience in the line stopper industry. All equipment shall meet the pressure rating for the line to be tapped.
b.Excavation and Found ation . The trench shall be excavated to the designated line and grade when required. The trench width shall be sufficient to permit work on the pipe and inspection of the work. Mains shall have a minimum trench width of 18 inches {460 mm} plus the outside diameter of the pipe with the depth sufficient to provide for foundation preparation and proper cover unless stated otherwise on the project plans. Trenches shall be properly sheeted or braced wherever needed to prevent cave -in or loose soil from falling into the trench. Sides of the trenches shall be kept as near vertical as possible. The trench shall be excavated to insure that the pipe rests upon the bottom of the trench for its full length. In the event that the bottom of the trench is in rock or is uns uitable material, the trench shall be excavated at a minimum of 6 inches {150 mm} below grade or as directed by the Engineer. The trench shall then be backfilled with crushed stone as specified in Section 853 or Engineer approved material up to the proper grade elevation. All excavated material that is not suitable for use as backfill shall be removed from the project site or otherwise properly disposed. The trench shall be dewatered to prevent standing or running water, and to allow for proper installation of the gas pipe.
c.Laying . The laying of pipe in finished trenches shall be started at the outlet end and shall be installed up grade. The pipe shall be laid to the line and grade shown on the project plans. The pipe shall then be examined to make sure that it is free of defects. Pipe shall be fitted and matched to form a smooth, uniform invert. The pipe shall be installed in accordance with the pipe manufacturer’s recommendations and as directed by the Engineer.
646.03 Construction Requirements.
Pipes shall be lowered so as to avoid da mage and unnecessary handling in the trench. The pipe shall be cleaned of debris and dirt when jointing the pipe. The ends of the pipes shall be securely closed when laying is stopped for the night to prevent animals and water from entering the pipe. Gas M ains shall have a minimum cover of 36 inches {910 mm} under ditches and 48 inches {1220 mm} under pavement unless stated otherwise on the project plans. Walking and working on or over the completed gas line, except as necessary for backfilling and tamping, shall not be permitted until at least 1 foot {300 mm} of backfill is in place over the top of the pipe.
d.Joints and Fittings . All steel pipe joints and fittings shall be welded. Fittings shall be in accordance with ANSI B 16.5 or ANSI B16.9. All joints shall be sealed for the entire circumference of the pipe providing a watertight joint. All polyethylene joints shall be welded as required by the Manufacturer’s requirements.
e.Backfilling . Backfilling shall be performed immediately after inspection as directed by the Engineer to secure the pipe position prior to proceeding to the next section. The backfill material shall be carefully deposited equally on both sides of the pipe in uniform layers not to exceed 6 inches {152 mm} in compacted thickness to a density of not less than 95 percent of AASHTO T 99 maximum density. Backfill that is not under roadbeds shall be compacted as directed by the Engineer to be consistent with surrounding materials. Where roadways and other crossings are disturbed, the Contr actor shall restore them to their original condition and shall replace all surface material and all paving, sidewalks, sod, or other disturbed surfaces, by furnishing all necessary new materials without extra compensation. All pipe shall be tested as noted in this Section, or the method prescribed by the Engineer, whichever is the more stringent, before complete backfilling of the pipe shall be permitted. All trenches and excavations shall be backfilled with approved natural soil or, when directed by the E ngineer, with select foundation backfill material. After completing the backfill, the Contractor shall promptly remove all surplus material, rubbish, and all equipment, leaving the site and adjacent areas in a neat and presentable condition.
f.Connectio n to Existing Gas System . Connection to the existing gas system shall be made as shown on the plans and as directed by the Engineer and designated as "hot tap". The connection shall be made to minimize interruption of service. The Contractor shall notify t he Utility at least 24 hours prior to connecting to the existing system. Service connections shall be made to the top or side of the main and shall be graded as to drain into the main unless otherwise noted on the plans.
g.Air Pressure Testing of Install ed Lines .
1.Mains . When a section of pipe is approved by the Engineer for testing, the Contractor shall furnish all materials, equipment, and labor to properly carry out the testing operation. A recording pressure gauge shall be used during the pressure test and the charts shall be provided by the Contractor to the Utility. The Contractor shall furnish, install, and remove any temporary bulkheads, flanges, and plugs when such are necessary for the testing operation. Unless approved otherwise by t he Engineer, all gas mains shall be tested before service lines are installed. The pipe shall be air pressured to 1 1/2 times the maximum allowed operating pressure (MAOP) for the system. The pipe shall hold the air pressure for 24 hours. The Contractor, a t his expense, shall locate and repair defective joints, sections, or valves until the leakage is eliminated. All observed leaks shall be repaired. After the Contractor has made the necessary corrections, the main shall be retested as described above until the line passes the necessary requirements. All tests, and retests, shall be at the Contractor's expense.
2.Service Lines . Service line testing shall be as noted for mains except for the pressure which must be held for 60 minutes.
h.Holiday Detector Te st. Immediately prior to lowering the pipe into the trench, the pipe shall be tested by an Engineer approved holiday detector.
646.04 Method of Measurement.
The Contractor, at his expense, shall locate and repair defective joints, sections, or valves. After the Contractor has made the necessary corrections, the main shall be retested as described above until the line passes the necessary requirements. All tests, and retests, shall be at the Contractor's expense.
646.04 Method of Measurement.
a.Gas Main and Gas Service Line . The actua l accepted length of gas main and gas service line laid or relaid shall be measured in linear feet {meters} along the center of the line, complete in place. Tees, wyes, crosses, bends and fittings shall not be deducted from the measurement for payment alon g the center of the line being laid.
b.Fittings . Fittings shall be measured individually per each fitting including bolts and gaskets as needed.
c.Valves . Valves shall be measured per each individually as one complete unit including a valve stem extension, where required, and a valve box.
d.Hot Tap . Hot taps shall be measured individually per each hot tap performed for the various sizes and types and shall include the tapping tee and saddle when necessary to perform the hot tap.
e.Valve with Box R eset A valve with box reset will be measured per each box reset and shall include the valve and the resetting of the valve box and cover.
f.Gas Valve Box Reset A valve box reset will be measured per each box reset and shall include the resetting of the v alve box and cover.
g.Line Stoppers. Line Stoppers shall be measured per each individually as one complete unit including installation, maintenance and removal as necessary to complete the operation.
646.05 Basis of Payment.
a.Unit Price Coverage .
1.General . Final acceptance of this work shall be subject to approval by the Utility Company involved. Therefore, payment for this work shall not be made until the Contractor has obtained the Utility's written approval that the work performed c omplies with the local codes and requirements of the Utility Company.
2.Gas Main . The accepted quantity of gas main laid or re -laid shall be paid for at the contract unit price per linear foot {meter}, complete in place, which shall be payment in full for furnishing and installing pipe; including joint material, making necessary pipe connections, pipe line markers, testing, excavating, backfilling, and for all materials, tools, labor, equipment and incidentals necessary to complete the work.
3.Gas Service Line . The accepted quantity of gas service line laid or re- laid shall be paid for at the contract unit price per linear foot {meter}, complete in place, which shall be payment in full for furnishing and installing pipe; and joint material, excavating, bac kfilling, and for all materials, tools, labor, equipment and incidentals necessary to complete the work.
4.Fittings . Fittings shall be paid for at the contract unit price for each fitting specified on the project plans and includes all labor, materials, e quipment and incidentals necessary to furnish and install the size fitting required.
5.Valve . Valves shall be paid for at the contract unit price which shall be payment for all labor, materials, equipment and incidentals necessary to furnish and install one valve, valve stem extension, where required, and valve box.
649.03 Construction Requirements.
6.Hot Tap . A hot tap shall be paid for at the contract unit price which shall be payment for all labor, materials, equipment and incidentals necessary to furnish and install one hot tap incl uding tapping valve.
7.Valve with Box Reset Valve with box reset will be paid for at the respective contract price which shall include all labor, materials, equipment and incidentals necessary to furnish and install the valve and to reset the box complet e in place.
8.Gas Valve Box Reset Valve box reset will be paid for at the respective contract price which shall include all labor, materials, equipment and incidentals necessary to reset the box complete in place.
9.Line Stoppers . Line Stoppers shall be paid for at the contract unit price for each line stopper complete in place, which shall be payment for furnishing and installation of the line stopper including all materials, tools, labor, equipment, excavation, backfilling and incidentals necessary to c omplete the work.
b.Payment shall be made under Item No. : 646-A ___ inch {mm} * Gas ** Laid - per linear foot {meter} 646-B ___ inch {mm} * Gas ** Relaid - per linear foot {meter} 646-C ___ inch * Fittings – per each 646-D ___ inc h {mm} * Valve with Box – per each 646-E ___ inch {mm} x ____ inch{mm} * Hot Tap – per each 646-G ___ inch {mm} Steel Line Stoppers – per each 646-H ___ inch {mm} __*__ Valve with Box Reset - per each 646-J Gas _***_ – per each * Show Type: Steel; Polyethylene ** Designate One Type: Main or Service Line . *** Valve Box Reset, etc. SECTION 649 ENCASEMENT PIPE FOR UTILITIES
649.01 Description.
This Section shall include the work of furnishing and installing an encasement pipe for a utility carrier pipe. An encasement pipe may be utilized as a carrier pipe as noted in this Section and when shown on the plans or directed by the Engineer. The type of installation will be based on the location of the encasement pipe. The three types of installation are designated as follows: Type 1 - Open cut. Type 2 - Jack and bore, or tunneling. Type 3 - Directional drilling. The Contractor may substitute the Type 2 or Type 3 installation for the Type 1 installation if the substitution is done without extra compensation. Type 2 and Type 3 installations are intended for use under existing facilities and where traffic is not to be disturbed.
649.02 Materials.
Materials furnished for use shall conform to the requirements of Section 862, Utility Encasement Pipe and other appropriate sections of these Specifications. The size and depth of pipe shall be as shown on the project plans or as described in the project proposal.
649.03 Construction Requirements.
a.General . Type 1 – encasement pipe installed by open trench method complying with requirements for installation and backfill given in Section 645.
Source: Alabama Standard Specifications for Highway Construction, 2022 Edition. Pages 540–543 of 934.