Thermal Pipe System - Pre-insulated Welded Steam, Condensate, High Temperature Hot Water  Steel Pipe -  Super Weld-Tite (CSI Specification Format) All square bracket locations [  ] call for a choice to be made or user input:

SECTION 23xxxx

UNDERGROUND PIPE AND FITTINGS

PART 1 - GENERAL

1.01	SECTION INCLUDES

A.	Extent of pipe and fittings required by this Section is indicated on drawings and/or specified herein.

B.	Types of pipe and fittings specified in this Section include the following:

1.	Piping Materials:

a.	Pre-insulated steel piping system.

2.	Pipe Fittings:

a.	Pre-insulated steel fittings to match pipe. 

1.02	QUALITY ASSURANCE

A.	Manufacturers:  Firms regularly engaged in manufacture of pipe and fittings of types and sizes required, whose products have been in satisfactory use in similar service for not less than 3 years.

B.	Installer's Qualifications:  [A firm with at least 3 years of successful installation experience on projects with piping Work similar to that required for project.][An installer who has been trained and certified by the manufacturer to have demonstrated proficiency in the handling and installation of this piping system.]
		
C.	All materials and installation shall be in conformance with the following:

1.	[Applicable State Code]

2.	ANSI B31.1 "Power Piping".

3.	ANSI B31.9 "Building Service Piping".
	
D.	Acceptable Manufacturers:

1.	Thermal Pipe Systems, Inc.
			
2.	Or Engineer's approved equal.

1.03	SUBMITTALS

A.	Product Data:  Submit catalog cuts, specifications, installation instructions, stress calculations and dimensioned drawings for each type of pipe, fitting, and joint for each piping system. 
	   
B.	[Record Drawings: At project closeout, submit record drawings of installed steam and condensate piping and piping products.]
	   
C.	[Maintenance Data:  Submit mantenance data and parts list for [steam] [condensate] materials and products.  Include this data, product data, shop drawings, and record drawings in maintenance manual.]

1.04	DELIVERY, STORAGE, AND HANDLING

A.	Where possible, store materials inside and protected from weather.  Where outside storage is necessary, elevate above grade and enclose with a durable, waterproof wrapping. 
		
B.	Protect flanges and fittings from moisture and dirt by inside storage and enclosure or by packaging with durable, waterproof wrapping.
		
PART 2 - PRODUCTS
                 
2.01	PRE-INSULATED WELDED STEEL PIPING SYSTEM

A.	Piping: Steel pre-insulated pipe shall be used for [steam] [high temperature hot water] [condensate] service.  The pipe sections shall be welded. Unless otherwise specified, all pipe, fittings, valves, and accessories shall conform to the requirements of ANSI B31.1 and shall be of the proper type for the pressure and temperature of the service.
		
B.	Steel Carrier Pipe and Fittings:

1.	Carrier pipe shall be black steel pipe conforming to ASTM [A53 ERW] [A53 or A106 Seamless] Schedule [40] [80] [Standard Weight] [Extra Heavy Weight] Grade B.  The spigot ends shall be beveled for welding.
			
2.	Fittings shall be preinsulated by manufacturer using the same insulation thickness and casing as the pipe. Where necessary laid-up fiberglass casing may be substituted on all or part of the fitting and shall structurally match the casing of the pipe.  A thrust plate of the proper size shall be provided when required by the design and shall be an integral part of the fitting.  Field applied thrust plates shall not be allowed except by special approval of the engineer.
		  
3.	Expansion shall be compensated for by the use of expansion loops and expansion elbows.  The system designer is responsible for properly sizing the expansion fittings.   Bolsters or other forms of outside cushions shall not be accepted as expansion fittings.
		  
C.	Fiberglass Casing Pipe:  Casing for the pre-insulated pipe system shall be reinforced thermosetting resin plastic (RTRP) pipe manufactured by the filament wound   process per ASTM D-2310 (RTRP-12E). Thickness shall be not less than [0.125"] [0.185"] for casing sizes 8" through 12" diameter and not less than [0.185"] [0.250"] for casing sizes 14" through 24" diameter.  

D.	Insulation:  Insulation shall consist of an inner layer of high temperature [calcium silicate] [Foamglas(r)] and an outer layer of polyurethane foam.

1.	Inner layer:

[Calcium Silicate Insulation: The calcium silicate shall be a hydrous material satisfactory for temperatures to 1200ºF.  Insulation shall conform to ASTM C-533 and Mil Spec Mil-1-2781.]

[Foamglas(r) Insulation:  The Foamglas(r) shall be a closed cell material satisfactory to 900ºF.  Insulation shall conform to ASTM C-522 and Mil Spec Mil-1-24244B.  Foamglas(r) shall be bore coated with Hydrocal B-11 to prevent abrasion.
			
2.	Outer layer: Polyurethane foam insulation shall meet the following specifications:

Type:  				Two component urethane
Compressive Strength: 	35 psi parallel minimum at 5% comp.
Shrinkage:  				None at 70ºF
Free Rise Density: 			2.0 to 3.0 lbs/cubic foot
Aged "K" (70ºF - 72 hours): 	0.160 BTU-in/hr-ft²-ºF
Closed Cell Content: 		90%

3.    Insulation Thickness shall be as shown in table below:
			
			Carrier Pipe		------ Insulation Thickness (in.) ------ 
			Size (in.)		Calcium Silicate		Polyurethane 
						or Foamglas(r)	
			1 1/2			1.00				2.05		
			2			1.00				1.81
			2 1/2			1.00				1.56
			3			1.00				1.25		
			4			1.00				1.25
			5			1.50				1.72		
			6			1.50				1.19		
				8			2.00				1.69		
				10			2.50				1.13	
				12			2.50				1.13
				14			2.50				1.50	
				16			2.50				1.50
			
4.	Insulation concentricity:  Carrier pipe shall be concentric to casing pipe.  The allowable maximum deviation from center line of carrier pipe shall be plus or minus 1/4 inch at the casing center point and plus or minus 1/16 inch at the end seals.
	
E.	Wall Penetration Sleeves:  Provide wall penetration sleeves where piping passes through masonry or concrete walls.  Sleeves in outside walls below and above grade shall be schedule 40 or standard weight coated black steel pipe or as specified by the Design Engineer.  Sleeves shall be held securely in proper position and location during construction. Sleeves shall be of sufficient length to pass through entire thickness of walls or slabs.  Refer to typical detail of wall penetration as shown.  In existing concrete manholes or building walls, penetrations may be made using the "core drilling" method, providing proper care is taken to drill the holes to the size needed and square to the line of the pipe.

F.	Wall Penetration Seals:  All wall penetrations shall be sealed to prevent water from entering the building or manhole.

1.	Mechanical Sleeve Seals:  Modular mechanical type, consisting of interlocking synthetic rubber links shaped to continuously fill annular space between pipe and sleeve, connected with bolts and pressure plates which cause rubber sealing elements to expand when tightened, providing watertight seal and electrical insulation.

2.	Manufacturer:  Subject to compliance with requirements, provide mechanical sleeve seals of the following:

a.	Thunderline Corp.

			b.	Proset

PART 3 - EXECUTION

3.01	GENERAL

A.	Installation of the piping system shall be done in accordance with the appropriate publications including ANSI B31.1 and the following specifications and instructions.  A manufacturer's field representative shall conduct an installation clinic to pre-qualify contractor personnel in the proper procedures for the installation. [Certification of instruction and competence shall be issued to those personnel so trained and only those so certified shall be permitted to perform work on the pipe.]  Good workmanlike procedures shall be followed.

B.	Factory furnished lengths of pipe shall be utilized to the maximum extent.  Field cutting of pipe shall be kept to a minimum.  Pipe shall be worked into place without springing or forcing, properly clearing all openings and equipment.  Pipe ends shall have burrs removed by reaming and shall be installed to permit free expansion and contraction without damage to joints.  Good workmanlike procedures shall be followed.
	
C.	Open ends of pipe lines and equipment shall be properly capped or plugged during installation to keep dirt or other foreign matter out of the system.

D.	When used for steam service, all piping shall be pitched with a grade of not less than 1 inch in 40 feet toward the drain point when applicable.

3.02	RECEIVING AND HANDLING SHIPMENTS

A.	Inspection:  Each shipment shall be inspected upon arrival at the jobsite.  It is the responsibility of the installing contractor to ascertain whether there has been any loss or damage.  The carrier is the contractor's agent.  Any pipe or equipment that arrives damaged or is lost in shipment shall be reported by the contractor.  Make overall inspection of the load.  If load is intact, ordinary inspection while unloading should be enough to make sure that the pipe has arrived in good condition.  It is the responsibility of the receiver to make certain that there has been no loss or damage.  Note specifically that any end packaging shall not show signs of damage.  If the load has shifted or end packing is damaged, then each piece shall be carefully inspected for damage.  Other obvious damage shall also be cause for rejection.  Check total quantities of each item against tally sheet (pipe, fittings, etc.).  Any damaged or missing items shall be noted on delivery receipt and the receipt returned to the carrier.  Notify the carrier immediately and make claim in accordance with the carrier's instructions.  Do not dispose of damaged material; follow procedure as directed by the carrier.

B.	Unloading Instructions:  The means by which the pipes are unloaded in the field is the decision and responsibility of the installing contractor.  To prevent the possibility of the core pipe from shifting within the casing pipe, do not stand a length on one end or raise it vertically.  Under no condition shall a pipe be dragged along the ground.  Do not lift fittings or pipe by inserting a bar, pipe, etc., inside of the core since damage to the pipe may result.  If any pipe is damaged in unloading and handling, mark the damaged area and set it aside.  Manufacturer's representative shall determine whether damaged casing can be repaired in the field and shall determine exact method for repair and instruct contractor in making repair.

C.	Storage:  Store pipe on dunnage in a flat area.  Support the barrel of the casing evenly.  Bell and spigot ends shall overhang dunnage.  Store random lengths separately where they will be readily available.  Individual lengths of pipe shall be stacked in piles no higher than 5 feet.  Protect pipe during long exposures (several months) to sunlight by covering it with canvas or other opaque material.  Provide for air circulation under the sheets.

D.	Loading Transfer Trucks:  Use trucks with long bodies so that pipe lengths do not overhang.  Make certain truck bed is smooth, without cross-strips, bolt heads, or other protrusions that could damage the pipe.  Short body trucks may be used if fitted with racks that properly support the pipe in a horizontal position.  The rack shall have supports spaced every 3 feet or less along the pipe lengths. Pad the contact areas to avoid damage to the pipe.

3.03	EXCAVATION

A.	Excavation shall take into account the need for the concrete anchor blocks where they may be required.  The trench bottom shall give uniform support along the entire length of any pipelines.  Where several pipelines are located in a common trench, the trench shall be wide enough to maintain the specified distances between adjacent lines, a minimum of 6" in pipe sizes up to 6" diameter and 12" minimum in sizes 8" and larger.  The excavation shall be in a straight line, except where fittings are located.
	
3.04	TRENCHING

A.	The trench depth shall allow for a minimum cover height of 24" over the top of the casing pipe. Keep excavations free of water during construction.  If it is necessary to remove unsuitable material to a depth greater than specified, refill over excavated area to the proper depth with specified bedding material and compact in 6" lifts to 95% of maximum density in accordance with ASTM D1557, Method D.  Excavate and replace soil disturbed and weakened by the Contractor's operations or soils permitted to soften from exposure to weather with bedding material and compact it with a plate-type vibratory compactor.
	
B.	The width of the trench at the top of the pipe shall be held to the minimum required for efficient and proper installation.  The minimum recommended trench width at the top of the pipe shall be one foot greater than the outside diameter of the casing.  Where two or more pipes are in the same trench, use the distance between outside casing of the outside pipes plus one foot.  To determine the maximum trench width, use above method for minimum plus two feet.

3.05	DISTRIBUTING PIPE ALONG TRENCH

A.	Pipe lengths may be strung along the line of the trench so as to minimize additional handling during installation.

3.06	PLACING PIPE IN THE TRENCH

A.	Super Weld-Tite pipe shall be mechanically passed into the trench.  The latest state and federal safety regulations shall be understood and observed.  If slings are necessary, use only canvas straps.  Do not use cable or chain slings.

3.07	BEDDING

A.	Bedding material shall be sand, pea gravel or other materials free of sharp objects, heavy clods, boulders, or frozen lumps as specified by the design engineer.  The approved bedding shall be used 6" under, around and over the pipe.  Utilize the best professional practices that apply to buried pressure piping.

3.08	ASSEMBLY OF PIPE AND FITTINGS

A.	Pipe and fittings shall be assembled in strict accordance with the manufacturer's printed directions by personnel who have been instructed in installation procedures by the manufacturer's representative.

3.09	TESTING

A.	Testing shall be performed and system proven tight before closure of insulated field joints or backfilling.  Prior to testing, flush pipe system with fresh water until piping is free of dirt and foreign matter.  Use only fresh water for field tests.  Air must be removed from system before starting tests.  A hydrostatic test of 150 psi or 1 1/2 times working pressure, which ever is greater, shall be placed on the system for a period of two hours.

B.	All field joints shall be air tested before backfilling.  Air pressure at 5 psig shall be maintained constant for 2 hours.  If a leak in a joint develops as indicated by a decrease in air pressure, the joints shall be tested using a soap suds solution to identify the point of leakage.  Once the leak has been identified, the joint(s) shall be repaired and the system re-tested.

C.	[Operational Test:  Operate complete system, or testable portions thereof, as approved by the Engineer through two cycles.  Each cycle shall consist of a period of at least eight hours with hot water leaving the system within 20ºF of design temperature [insert design temperature] and a period of at least four hours with heat off and no flow.]

3.10	BACKFILLING

A.	Backfilling of trenches shall progress as rapidly as construction, testing, and acceptance of work permits.  Uniformly compact and grade bottom of trenches.  After installation of pipe and bedding material, backfill as follows.  Place initial backfill in layers to a depth of 12" of the initial bedding.  Compact the material to a density equivalent to the surrounding undisturbed soil or to 90% of maximum density (ASTM D1557, Method D), whichever is greater.  Backfill remainder of trench in one-foot lifts and compact to 90% maximum density (ASTM D1557, Method D).  For trenches excavated in roads, streets, or located under structures, place backfill in 6" layers to top of trench and compact each layer to at least 95% maximum density (ASTM D1557, Method D).

3.11	FIELD CUTTING PIPE TO A SPECIFIC LENGTH

A.	Field cutting of pipe shall be performed in strict accordance with the manufacturer's printed directions by personnel who have been instructed in installation procedures by the manufacturer's representative. 
		
3.12	ANCHOR BLOCKS

A.	Anchor blocks shall be installed wherever expansion must be contained so to activate expansion loops, expansion elbows at changes of size, at reducers and some crosses and tees; at stops as a dead end; and where thrust must be curtailed, as at a valve or similar equipment.  The above situations may occur either where the fittings, etc., are directly buried in the soil or where they are located in a manhole.
		
B.	Anchor blocks shall be designed for maximum anticipated thermal forces.  Size and type of anchor blocks, as shown on the contract drawings, depend on expected expansion, pipe size, and the type of soil.
		
C.	Anchor blocks shall be installed using a concrete having a compressive strength of not less than 3000 psi minimum ultimate 28 days compressive strength, air entrained, with water reducing admixture. Anchor blocks shall be poured on and against undisturbed soil or soil tamped to 95% proctor density.

D.	Safe Bearing Loads:  The approximate safe bearing loads of various soils given in the following table are for horizontal thrusts when the depth of cover over the top of the pipe exceeds 2 feet.

SOIL					SAFE BEARING LOAD (lbs./sq. ft.)					
Soft Clay						1,000
Sand							2,000
Sand and Gravel					3,000
Sand and Gravel Cemented with Clay		4,000	
Hard Shale						10,000

E.	Pre-insulated fittings shall be provided with anchor plates designed to transfer expansion loads from the steel pipe to the concrete thrust blocks.  The entire surface of the steel plates shall be coated.  During manufacture steel plates shall be sealed against FRP casing.	

3.13	STARTUP PROCEDURE

A.	Startup procedure shall conform to generally accepted practices and be done in a workmanlike manner.  The line shall be filled slowly from any available low-pressure source.  The water may be introduced from lines in service directly through valved connections or by temporary connections to taps made in the new line.  All valves and other control points in the line that are open as the line filling begins shall be closed gradually to avoid the possibility of water hammer.

B.	Manufacturer's Written Certification:  After testing and prior to start-up of the system, the manufacturer must certify in writing that the system was installed per the manufacturer's installation instructions.

END OF SECTION