Polyethylene Encasement For Ductile Iron Pipe

Polyethylene Encasement (POLYWRAP)
Tubular Polyethylene Encasement Protection
for Cast Iron, Ductile Iron and Steel Pipe

polyethylene encasement, polywrap, pipe protection tapes

Advantages of Polyethylene Encasement

When compared to other corrosion control methods available for gray and Ductile Iron pipe, polyethylene encasement offers many advantages.

  • It is inexpensive.
  • It requires no monitoring or maintenance.
  • It has no operating costs.
  • It will not deteriorate while underground.
  • It is easy to install.
  • It is easy to repair damaged areas. (It is important that damaged areas be repaired with adhesive tape.)
  • It requires no special handling or packaging during shipment of the pipe.

Polyethylene encasement is the easiest, most economical and most effective method of corrosion protection for Ductile Iron pipe and fittings installed in aggressive soils.

  • Requires no monitoring or maintenance.
  • Will not deteriorate while underground.
  • Easy to install.

Polyethylene film prevents contact between the pipe and the surrounding soil for corrosion protection. However, it is not expected to be an airtight or watertight encasement. It is available in Natural (clear), Black or custom colors and in several widths suitable for all pipe sizes.

Polywrap Installation Guide
(Printable Version)
Polywrap Sizing Chart Polywrap Sizing Chart Page (PDF on left)
Polyethylene Encasement- FAQs



Effective, Economical Protection for Ductile Iron Pipe In Corrosive Environments

THIS POLYETHYLENE SLEEVE (polywrap) is placed on Ductile Iron pipe to prevent corrosion. It does not have to be sealed watertight, but it should be installed so that no dirt or bedding material comes in contact with the pipe. All lumps of clay, mud, cinders, etc., on the pipe surface should be removed before the pipe is covered with polyethylene. If the polyethylene is damaged, it must be repaired before the trench is backfilled.

Small holes or tears can be repaired with a piece of tape placed over the hole. Large holes or tears should be repaired by taping another piece of polyethylene over the hole. Overlaps, ends, and repairs can be held in place with tape or plastic tie straps until the trench is backfilled. Other general tips for proper installation include:

  • When lifting polywrapped pipe with a backhoe, use a fabric-type “sling” or padded cable to protect the polyethylene.
  • When installing polywrap below the water table or in areas subject to tidal action, seal as thoroughly as possible both ends of each polyethylene tube with adhesive tape or plastic tie straps at the joint overlap. Also, place tape or plastic tie straps around the pipe at two (2) foot intervals.
  • Quality of installation is more important than the actual sequence followed.
Polywrap Installation Guide (Printable Version)

Clean all dirt, cinders, etc., from the surface of the pipe. Cut polyethylene two (2) feet longer than the pipe. Slip polyethylene over spigot end and bunch.

Dig bell holes at joint locations, lower pipe into trench and make up joint.

Move cable hoist to bell end of pipe and lift enough to slip polyethylene along pipe.

Pull polyethylene forward from previous joint over the bell and secure in place.

Pull polyethylene from new pipe over this same bell, providing a double layer of polyethylene and secure in place.

Take up slack in the tube along the pipe barrel, making a snug but not tight fit. Fold over on top of pipe and secure in place about every three (3) feet.

Make sure any tears in the polyethylene are repaired with tape or another piece of polyethylene secured over the damaged area.

Backfill the trench according to specifications, being careful not to damage the polyethylene while tamping around pipe. Backfill should not contain material that might damage the polyethylene.

Tapping Polywrapped Pipe

Polywrap Installation Guide (Printable Version)

When tapping polywrapped Ductile Iron pipe, the following procedure is recommended.

  • STEP 1: Wrap two or three layers of tape completely around the pipe where the tapping machine will be placed.
  • STEP 2: Mount the tapping machine on the taped area and make the tap directly through the tape and polywrap. Install corporation stop.
  • STEP 3: Inspect the entire area for damage and repair if necessary.
  • STEP 4: Wrap any connected copper service line within three (3) feet of the pipe with polyethylene.
  • STEP 5: Backfill trench as described before.
ANSI /AWWA Standards: ANSI/AWWA C105/A21.5, Polyethylene Encasement for Ductile Iron Pipe Systems. In the United States, the film is specifically manufactured to meet the formulation, physical tests, thickness, and dimensional requirements specified in standard ANSI/AWWA C105/A21.5.
For immediate assistance, call 800 -WRAP-A-PIPE (800-972-7274)
Manufacturer and Distributor of Pipeline Protection Products,
Polyethylene Encasement For Ductile Iron Pipe
Underground Tapes, Pipe Coatings, Pipe Tapes, Cathodic Protection and Pipe Products

Address: 5202 Argosy Ave., Huntington Beach, CA 92649 - Phone: 714-897-0700 - Fax: 714-897-0600
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