Specification for Sliplining with Large

Diameter (21” - 60”) Closed Profile PVC Pipe

 

1.         Intent:  The intent of segmental PVC Sliplining is to renew existing sewers or culverts by insertion of sections of Vylon Slipliner Pipe into a live or empty existing pipe.  When complete, the liner pipe will extend from end to end of the failing sewer or culvert.

 

2.         Reference Specifications:  This specification references American Society of Testing and Materials (ASTM) standard specifications, which are made a part hereof by such reference and shall be the latest edition and revision thereof.

 

ASTM F 1803            Poly (Vinyl Chloride) (PVC) Closed Profile Gravity Sewer Pipe and Fittings Based on Controlled Inside Diameter.

 

ASTM D 1784           Rigid Poly (Vinyl Chloride) (PVC) Compounds and Chlorinated Poly (Vinyl Chloride) (CPVC) Compounds

 

ASTM D 2412           Determination of External Loading Characteristics of Plastic Pipe by Parallel Plate Loading.

 

ASTM D 3212           Joints for Drain and Sewer Plastic Pipes Using Flexible Elastomeric Seals.

 

ASTM F 477              Elastomeric Seals (Gaskets) for Joining Plastic Pipe

 

3.         Materials:  Pipe shall be manufactured from a PVC compound having a minimum cell classification of 12364A as defined in ASTM D 1784.  Gasket shall meet the requirements of ASTM F 477.

 

4.         Manufacturing:  Pipe shall be closed profile, ASTM F 1803 for 21" - 60" diameters with a tongue and groove gasketed joint.  The joint is designed to provide a constant inside/outside diameter at the joint.  The joint shall meet the requirements of ASTM D 3212.  Liner pipe shall have a minimum 46 psi pipe stiffness when tested in accordance with ASTM D 2412.

 

5.         Liner Pipe Material Tests:  Tests for compliance with this specification shall be made according to the applicable ASTM Specifications at the time of manufacturing.  Upon request, a certificate of compliance with this specification shall be provided by the manufacturer.  In addition, the purchaser may, at his own expense, witness inspection and testing of the pipe, at a time convenient to the Owner and the Manufacturer.

6.         Nominal Dimensions:

 

 

Nominal

Diameter

(in.)

Outside Diameter

(in.)

Inside Diameter

(in.)

21

22.290

20.750

 

24

25.115

23.500

 

27

28.232

26.500

 

30

31.415

29.500

 

32

33.800

31.500

 

33

34.800

32.500

 

36

37.800

35.500

 

38

40.000

37.500

 

39

41.200

38.500

 

42

44.200

41.500

 

48

50.570

47.500

 

54

57.000

53.500

 

60

63.350

59.500

 

 

 

7.         Preparatory Procedures:  The following procedures shall be adhered to unless otherwise approved by the Owner:

 

a.         Cleaning and Inspection:  Prior to sliplining, the line must be cleaned of debris and accumulated solids.  If cleaning and inspection has been performed by the Owner or others, copies of the original reports and records may be used by the Contractor in planning and execution of the work.  The Contractor is responsible for confirming the accuracy of the reports and records.  If the Owner has not performed this work or if the work is not satisfactory, the Contractor shall perform additional cleaning so that the installation of the liner pipe is not hindered.  Upon consent or direction of the Owner, the Contractor may TV inspect the sections or lengths to be sliplined and shall record the locations of all obstructions and lateral connections.

 

b.         Obstruction Removal:  It shall be the responsibility of the Contractor to clear the line of obstructions, solids, dropped joints, or collapsed pipe that will prevent the insertion of the liner pipe.  If inspection reveals an obstruction that is not at the location of the entry pit, the Contractor shall remove or repair the obstruction.  Such repair shall be approved by the Owner prior to the commencement of the work.

 

c.         Flow Control:  Bypass pumping is not generally required for the installation of PVC Slipliner Pipe.

 

d.         Mandrel Testing:  A mandrel of at least the outside diameter of the Vylon Slipliner Pipe shall be pulled through the line prior to any insertion attempts.  A four foot long section of Vylon Pipe may be used in place of a mandrel for size testing.  If there are offset joints, sags, depressions or slight bends in the line, a full length of the liner pipe shall be pulled through the line to verify the planned diameter and length will fit.

 

c.         Excavation:  Insertion pits should be located considering conditions of the existing pipe, directional changes, surface conditions, and pulling or pushing distances.  The number of insertion pits may be reduced by sliplining in both directions from a single insertion point.  The insertion pit should be long enough to accommodate a complete length of slipliner pipe plus five feet.  The width of the insertion pit should be sufficient to allow workers enough room to remove the crown of the existing pipe and install the slipliner pipe (usually a minimum of two to three feet on each side of the existing pipe.  The sides and ends of the insertion pit shall be sheeted or braced in order to provide a safe working environment.

 

8.         Installation Procedures:

 

a.         Insertion:  Sections of liner pipe shall be field connected at the insertion point.  An elastomeric gasket meeting the requirements of ASTM F477 shall be used to provide a sealing system at each joint.  Maximum allowable joint deflection shall be 3 degrees.  Subaqueous gasket lubricant provided (or approved) by the pipe manufacturer shall be used in assembling the joints.

 

b.         Reinstating Lateral Connections:  After the liner is installed, the Contractor shall restore service to all laterals.  Depending on liner pipe diameter and flow conditions, some lateral connections may be reinstated manually from within the liner pipe.  Other connections may require point excavation to restore service to the lateral or installing a “piggy-back” collection line to the nearest manhole.

 

c.         Sealing at Termination Points:  The annulus between the liner pipe and the host pipe shall be sealed at termination points and at intermediate structures.  Bulkheads shall be constructed in sequence from upstream to downstream allowing sewage trapped in the annulus to escape.  If annular grouting is to be performed, grout tubes and ventilation tubes shall be constructed into the bulkheads.

 

d.         Annular Grouting:  The annulus between the liner pipe and the host pipe may require grouting.  The Owner will make this determination on each installation.  Several grouting methods may be used at the contractors discretion with the approval of the Owner.  Some of these grout insertion methods include:

·        Holes drilled from grade through the crown of the host pipe.

·        Gravity flow or low pressure pumping of grout from upstream bulkhead to downstream bulkhead.  If low pressure pumping is used, pump pressures shall not exceed five (5) psi.

 

IMPORTANT NOTE:  Grouting is not to be considered a structural component of the sewer.  Grout is placed to provide liner pipe stabilization, to protect the liner pipe if the host pipe is in structural distress, to fill voids in the pipe zone and to stop water infiltration through the host pipe annulus. The annular grout should have a 28 day compressive strength greater than 100 psi and less than 1000 psi.  Grout should consist of Portland cement, pozzolanic fly ash and water.  Foaming agents used in the production of cellular grouts shall be acceptable upon approval of the Owner. No aggregates shall be used in the grout mix.  Sand content, if used, shall be kept to a minimum. All grout designs shall be approved by the Manufacturer. With annular spaces of more than three inches, flotation of the liner should be taken into consideration.  To avoid potential liner collapse, the recommended maximum grout pressure is 5 psi with a safety factor of 4:1.  Contact the pipe manufacturer for consultation and additional information.

 

e.         Encasement:  At points where the liner is exposed (service connections, insertion pits, etc.), the liner pipe may, at the Owner’s option, be encased in compacted sand, cement stabilized sand and/or other high density material.  In preparation for the placing of the encasement material, debris shall be removed along each side of the liner pipe down to and under the haunches.  After the encasement material is in place and accepted by the Owner's Representative, backfill is placed and compacted to the required finished grade in accordance with the job specifications.  Particular care shall be taken to insure compacting of earth beneath lateral connections in order to prevent subsidence and resultant stress at the connections.

 

9.         Final Acceptance:   The liner pipe shall be as free from visual defects, damage, or excessive deflection as commercially practicable.  There shall be no visible infiltration through the liner, at the joints, and at the service connections.

 

10.       Measurement for Payment:  Payment for sliplining of sewers shall include inspection and cleaning the existing sewer, removal of obstructions, excavation of insertion pits, installation of liner, reconnection of laterals, construction of bulkheads, grouting of annular space, and backfill and restoration of the pit locations.  Payment for these items shall be at the unit price bid or included in the price per linear foot of installed liner pipe.  Measurement is based on the actual linear feet sliplined including linear feet of liner through manholes.