What is MDPE

MDPE pipe has been the standard for natural gas distribution systems since the 1960s.  This solid yellow pipe is a proven solution for systems operating under 125 psi pressure.  WL Plastics manufacturers medium-density polyethylene (MDPE) pipe in compliance with specification ASTM D2513 and Federal Code 49CFR192.59 (no rework) under strict quality control.  WL Plastics has dedicated extrusion lines for producing high-quality unimodal PE2708 MDPE at two of its ten state-of-the-art manufacturing facilities (Titusville, PA and Lubbock, TX). We have over 1 billion pounds per year of polyethylene pipe production capacity. WL Plastics high-volume production allows it to manufacture pipe at the lowest possible cost and to fulfill customer orders quickly and efficiently while maintaining the highest quality standards. 

WL Plastics utilizes unimodal PE2708 resin mixed with a yellow color masterbatch to manufacture its MDPE pipe.  The yellow masterbatch provides UV protection from outdoor degradation for up to 3 years.  MDPE compounds have an ASTM D3350 cell classification of 234373E or 234375E.  WL Plastics primary PE2708 resin is INEOS K38-20-188 and Chevron Phillips TR418Q is its backup.  Both resins are listed in PPI TR-4 with dependent listings for WL Plastics.  PE2708 pipe has a design life greater than 100 years when properly installed and operated.  See WL129 for more information on the PE2708 compound used to make MDPE pipe.

Available Sizes and packaging

WL Plastics offers MDPE pipe in CTS sizes ½ - 1.25 and IPS sizes ½ - 24 in a variety of wall thicknesses and DR’s.  See WL129 for more information on available sizes.

MDPE Production

Resin arrives at WL Plastics facilities primarily by rail and is unloaded through a closed loop vacuum system into silos after QA testing has verified the Certification of Analysis.  This closed loop handling system containing elutriation and magnets, and a wire mesh screen pack at the outlet of the extruder, and no-rework ensure contaminant free pipe.   After natural resin is mixed with yellow color masterbatch and dried at 140F, it is transported to well-maintained and state-of-the-art extrusion equipment that are gravimetrically controlled.  Hourly measurements by production personnel, continuous in-line 360 degree ultrasonic measurement, and frequent quality assurance checks ensure dimensional tolerances are met.  

Quality Control & Third-Party Certifications

WL Plastics gas distribution piping is manufactured with unmatched Quality Assurance.  Each WL Plastics manufacturing facility is ISO 9001 certified and equipped with state-of-the-art labs for resin and pipe compliance testing.  QA labs operate under a ISO 9001 certified Quality Management System Manual by well-trained and experienced personnel.  Lab equipment is calibrated annually to A2LA standards.  WL Plastics maintains other third-party certifications besides ISO 9001 including NSF Gas, NSF-14, NSF-61, and FM.

Print Lines

All MDPE gas distribution piping is marked with laser etching at intervals of 2-ft with the print requirements of D2513 including the letters “NR” for no rework and the ASTM F2897 Tracking & Traceability bar code and alpha-numeric code.  Laser etching offers a better permanent print solution than ink jet and heat indent print while giving WL Plastics better control of print depth than heat indent print.     

Technical Support

WL Plastics maintains a well-qualified Engineering staff to support its natural gas piping customers.  Engineers actively participate in the American Gas Association Piping Materials Committee and Gas Piping Technology Committee, Plastics Pipe Institute, American Society of Mechanical Engineers, American Petroleum Institute, ASTM International, and CSA to provide technical expertise and service to these organizations.