TransCanada PipeLines

Re: Foam Pillows

Dear Mr. O Neill
TransCanada Pipelines standard specifications include the use of foam pillow supports during pipeline construction. The foam supports are generally used in lieu of sandbags in situations where the use of the sandbags is not deemed practical.

TransCanada Pipelines endorses the use of polyurethane foam pillows and ditch breakers subject to their installation as per our Pipeline Construction Specifications (ie: correct density, compressive strength and dimensions.)

Yours Truly,
Brian Peterson
Project Engineer Pipeline Design

SPIE CONSTRUCTION

Re: Foam Pillows

Dear Barney

My experience in using fabricated foam pillows in the trench bottom as pipe support started in 1982. They worked successfully then and are still our preferred method of pipe support in gravel or rock trench applications.

The Major advantages from a construction perspective are the following:

1. They are safe, light and easy to handle
2. They can be prefabricated off-site on non-construction labour rates
3. They are far superior to sandbag support as the density of the foam allows for differential settlement underneath a section of pipe, thus avoiding pressure points which can dent the pipe. The sandbag has no flexibility.
4. Owner companies readily accept the pillows and are not concerned with long term pipe support.
5. Tests have shown that the polyurethane foam is essentially unchanged in form after year of burial.
6. Environmental costs which respect to sandpit development and reclamation are increasing and more time consuming.
7. The consistency of foam density and design shape is guaranteed.
8. They can be used on pipe sizes of up to 48"

The major factor to consider in using the pillow supports is to place sufficient pillows in pressure areas such as sag bends and tight areas. In addition it is important that the spacing of the pillows adequately and uniformly allow for the added weight of the water filled pipeline (if hydro testing is performed).

Once the economic viability of the foam pillows is verified we are very satisfied and confident in their use.

Best regards,
Spie Construction Inc.
J.J Breen, P. Eng.
Vice President, Engineering

Louisbourg Pipelines Inc.

Re: Foam Pillows

Dear Barney O Neill

Gentlemen:
Further to our recent conversation this letter is issued to attest to the benefits of foam pillows in sand padding applications.

Louisbourg has constructed hundreds of kilometers of NPS 42 pipelines in Northern Canada and has been very successful with the use of foam pillows. We attribute the fact that we have not had any indications after the electronic tool run, to use of foam pillows.

The pillows serve as excellent support for the pipe, this allows for the sand bedding to run under the pipe and provide the necessary bedding.

The installation of pillows is easy and they can be utilized at spacing suitable to the ditch conditions (side bends, over bends, etc.). They afford the comfort to the Client and the Contractor that the correct amount of bedding will be used under the pipe, due to their uniform height, consequently there is no room for error, nor is it required for inspection to probe the bedding for the correct height.

When the conventional method of bedding is used, there is the possibility that rocks will roll off the spoil and embed into the sand, without anyone noticing. If this happens with pillows in place, the pillow supports the pipe to alleviate pipe damage and allows the inspection to notice any rocks that may have fallen.

Further to our specific situations, when a ditch is padded well ahead of the lowerin as is necessary, using sand bedding only, we are left with a high risk of a washout in the event of rain. When pillows are used the bedding is placed after the pipe is lowered in minimizing the risk of washouts. They also serve as water barriers on minor slopes when no breakers are installed.

In our view, foam pillows afford the best protection and we highly recommend their use to enhance reliability and productivity on any pipeline construction project.

We trust this clarifies the benefits we have incurred with the use of foam pillows.

Best regards,
Walter Martinello
Manager, Pipeline Services