U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Plastic Pipe

Transcription

1 Plastic Pipe Materials, Joining, Installation, & Other Considerations

2 Some of the pipe that you may see? Around the late 1950 s to early 2000 s Thermoplastics

3 Plastic Materials Must Meet: ASTM D-2513 (Thermoplastic) (1999 Edition pipe materials) (1987 Edition - marking) (2009a) all PE Polyethylene ASTM D-2517 (Thermoset) (2000 Edition)

4 Thermosetting (Fiberglass)

5 Thermoplastic Pipe Materials Acrylonitrilc-Butadiene-Styrene Cellulose-Acetate-Butyrate Poly Butylene Polyethylene Polyvinyl-Chloride Polyamide (ABS) (CAB) (PB) (PE) (PVC) (PA)

6 Polyethylene Medium Density High Density

7 "Grades" of Polyethylene Refers to Physical Properties Tensile Strength Elongation Temperature Brittleness Environmental Stress Crack Resistance

8 Polyethylene "Types" Type Nominal Density Range I Low II Medium III High IV Higher High

9 Long Term Hydrostatic Strength Material Designation ABS 1210 CAB MH08 PB 2110 PE 2406 PE 3408 Polyamide (Yellow) Polyamide (Black) PVC 1120/1220 Thermosetting 23 C (73 F) 2,000 1,600 2,000 1,250 1,600 2,500 3,150 4,000 11,000

10 Marking Designations First Two Digits (47) Grade of Material Second Two (10) Half of 73 F Letters C Temp. (140 F ) E Carbon Black & UV From ASTM D (a) Edition (D-3350)

11 TABLE 1 Polyethylene Compound Requirements Pipe Material Designation Code PE 2708 PE 4710 Density Cell Classification per Specification D SCG Resistance Cell Classification per Specification 7 7 D3350 HDS for water at 73 F (23 C) per Test Method D (5.5) 1000 (6.9) and PPI TR-3, psi (MPa) Color and UV Stabilizer Code per Specification C or E C or E D3350 Melt flow rate per Test Method D1238, g/10 min 0.40 Cond. 190/2.16 or 20 Cond. 190/ Cond. 190/2.16 or 20 Cond. 190/21.6 HDB at 73ºF (23ºC) per Test Method D2837 and PPI TR-3, psi (MPa) Minimum HDB at 140ºF (60ºC) per Test Method D2837 and PPI TR-3, psi (MPa) 1250 (8.6) 1600 (11.0)

12 Design of Plastic Pipe P=2s (t / D-t) x 0.32 P=(2s / SDR-1) x 0.32 (seldom used) (most used) P = Design Pressure (psi) S = Long-term Hydrostatic Strength (HDB) D = Specified Outside Diameter t = Specified Minimum Wall Thickness SDR = Outside Diameter / Wall Thickness

13 Design of Plastic Pipe PA-11 Pipe Design Factor P=2s (t / D-t) x 0.40 P=(2s / SDR-1) x 0.40 (seldom used) (most used) = 0.40 for (Only) PA-11 pipe produced after January 23, 2009 with a nominal pipe size (IPS or CTS) 4-inch or less, and a SDR of 11 or greater (i.e. thicker pipe wall).

14 Design Limitations a) Design Pressure 100 psig for: Distribution Systems Class 3 and 4 Locations But stay tuned

15 Design Limitations b) Temperature Requirements Cannot Go Below - 40 F (if all components are approved for this) Cannot Go Above Long-Term Hydrostatic Test Strength (140 F)

16 Variation in Soil Temperatures Three Feet Below the Surface, ºF Location January April July Massachusetts Michigan Washington Illinois Nebraska Kentucky Colorado (Plains) Alabama Mississippi Texas (Panhandle) Texas (South) Oklahoma

17 Design Limitations e) Design Pressure 125 psig for: Pipe Produced after 07/14/04 PE or per ASTM D a Nominal Pipe Size is 12 inches or less Per Amendment

18 Design Limitations f) Design Pressure 200 psig for Polyamide 11 (PA-11): Pipe produced after 01/23/09 Nominal pipe size is (IPS or CTS) 4-inch or less Pipe is SDR-11 or greater (i.e., thicker pipe wall) Per Amendment

19 Subpart F Applies to all joints except steel welding

20 Joining of Materials Other Than By General Welding b) Each Joint Must Be Made In Accordance With Written Procedures Procedures Must Be Proven By Test c) Each Joint Must Be Inspected

21 General Requirements For Plastic Pipe A) Plastic Pipe May NOT be Joined by THREADED or MITER Joints Solvent Cements (PVC) - ASTM D 2513 Heat Fusion Joints (PE) Must be joined by a device which holds the ends aligned and heats uniformly

22 Can't Do This or This

23 General Requirements For Plastic Pipe (cont.) Adhesive Joints (Fiberglass) ASTM D 2517 Mechanical Joints (All Plastic) Gasket Compatible with Plastic Rigid Internal Tubular Stiffener

24 Mechanical Fitting Types By Category Classification 1. Those That Provide Pressure Seal and Restraint Equal to Forces That Cause Pipe Yield. 2. Those That Provide Pressure Seal and Restraint Equal to Forces Generated by Temperature Changes. 3. Those That Provide Pressure Seal Only.

25 Mechanical Joints Necessary measures must be employed to prevent pullout

26 Qualifying Joining Procedures (a)Written Joining Procedures Must Be Qualified By Testing Heat Fusion, Solvent Cement, and Adhesive Joints Burst Tests Per ASTM D2513 or ASTM D2517(Sustained Pressure or Quick Burst)

27 Qualifying Joining Procedures (cont.) (a)Written Joining Procedures Must Be Qualified By Testing Heat Fusion, Solvent Cement, and Adhesive Joints Destructive Test for Lateral Connections Tensile Test (ASTM D638) for Non-Lateral Connections Electrofusion (ASTM F1055)

28 Qualifying Joining Procedures (cont.) (a)Written Joining Procedures Must Be Qualified By Testing Mechanical Joints Subject Five Specimens to Tensile Test (ASTM D638) Specimen Must Fail Outside of the Joint Written Procedures Must Be Available to Persons Making and Inspecting Joints

29 Qualifying Persons To Make Joints (A) Person Must Be Qualified Under Joining Procedure Training or Experience; and Make a Specimen Joint

30 Qualifying Persons To Make Joints (cont.) B) Specimen Joint Check Visually Examined (Compared to Photos of Acceptable Joints); and Subjected to Testing per (a) (Burst or Sustained Pressure); or

31 Qualifying Persons To Make Joints (cont.) Ultrasonic Test; or Cut Straps (Visual Examination and Deform)

32 Qualifying Persons to Make Joints (cont.) Retesting Required If: Person Doesn't Join in Twelve Months; or 3 or 3% Joints Found Unacceptable (Under Test as Required by ) Records Must be Kept.

33 Inspection of Joints No Person May Inspect Joints Unless That Person Has Been Qualified By Training or Experience.

34 Additional Concerns

35 Installation of Valves Plastic Valves Must Be Installed to Prevent Torsional, Shearing, and Secondary Stresses.

36 Repair of Plastic Pipe Each Imperfection or Damage That Would Impair the Serviceability of Plastic Pipe Must Be Repaired or Removed. 10% practice in O&M

37 Installation Of Plastic Pipe a) Plastic Pipe Must be Installed Below Ground (exceptions in g & h). 2 years? b) Plastic Installed in Vaults and Other Below Ground Enclosures Must Be Encased in Gas- Tight Metal Pipe and Fittings Protected From Corrosion. c) Shear or Tensile Stresses Must Be Minimized.

38 Subpart G

39 Installation of Plastic Pipe (d) Minimum Wall Thickness.090" O.D. of.875 (7/8) May Be.062 (e) Plastic pipe that is not encased must have an electrically conducting wire or other means of locating the pipe while it is underground. Tracer wire may not be wrapped around the pipe and contact with the pipe must be minimized but is not prohibited. Tracer wire or other metallic elements installed for pipe locating purposes must be resistant to corrosion damage, either by use of coated copper wire or by other means.

40 Installation Of Plastic Pipe (f) Leading Ends Must Be Sealed Before Insertion.

41 Installation Of Plastic Pipe (g) Uncased plastic pipe may be temporarily installed above ground level under the following conditions: (1) The operator must be able to demonstrate that the cumulative aboveground exposure of the pipe does not exceed the manufacturer's recommended maximum period of exposure or 2 years, whichever is less.

42 Installation Of Plastic Pipe (h) Plastic pipe may be installed on bridges provided that it is: (1) Installed with protection from mechanical damage, such as installation in a metallic casing; (2) Protected from ultraviolet radiation; and (3) Not allowed to exceed the pipe temperature limits specified in

43 Service Lines: Plastic a) Plastic Above Ground and Outside of Buildings Must: Be Protected Against Deterioration and External Damage Plastic Cannot Support External Loads

44 Plastic Can't Support Loads

45 Service Lines: Plastic b) Plastic Inside a Building Must Be Protected Against External Damage

46 Storage of Plastic

47 Storage of Plastic

48 ASTM D A1. Supplemental Requirements for Gas Pressure Pipe and Fittings Produced from Polyethylene (PE) Material: A1.5.7 Outdoor Storage Stability: PE pipe stored outdoors and unprotected for at least two years from date of manufacture shall meet all the requirements of this specification. PE pipe stored outdoors for over two years from date of manufacture is suitable for use if it meets the requirements of this specification.

49 Handling of Plastic Bend Radius should be no less than 20x's pipe outside diameter

50 Squeeze Off s

51 Static Electricity

52 Recommended Practice

53 Odorant Softens Poly

54 The End Questions?

55