In nearly every substation nationwide, technicians contend with small oil leaks from aging transformers. Mechanics and operators often spend a significant portion of their workdays monitoring these constant leaks, and installing and replacing absorbent padding to contain the oil.

At Con Edison, workers used to contain small leaks by placing catch trays, lined with absorbent padding, underneath equipment. The mechanics routinely monitored the padding for saturation and frequently changed them out. This method consumed a significant amount of labor and resources.

Six months ago, however, Con Edison began working with New Pig Corp. on a new type of absorbent padding called the Oil-Only Wrap. Rather than placing a tray underneath the leak and continually changing out padding, the technicians could use the new valve wrap to attack the leak directly at its source, which proved to be a more efficient way of dealing with leaking equipment.

Field Testing

While New Pig has offered absorbent padding for years, this time the company worked directly with Con Edison's substation department to make practical improvements to the product. Con Edison beta tested two new valve wraps, including the MAT469 and the MAT471.

New Pig developed test products, and Con Edison's mechanics tested them out in the field and made observations. While versions of these products already existed, field specialists, supervisors and mechanics offered suggestions on how the products could be improved and tailored to substation equipment.

For example, the utility asked New Pig to thread the absorbent wrap with strings, so workers could tie them around oddly shaped equipment. These polyethylene drawstrings ease installation by allowing the users to quickly secure the wrap into position and cinch it tightly around leaking valves, fittings, flanges and pipes of any shape or size.

In addition, Con Edison asked New Pig to add a Velcro strap. This freed up the mechanics' hands and allowed them to fasten the padding to the equipment with the strings. The Velcro proved to be a useful feature for vertical valves or large, oddly shaped equipment.

Con Edison field employees also advised New Pig to add a non-permeable clear poly back, which mitigates pollution by preventing saturated absorbent pads from leaking onto concrete or bluestone. The oil absorbs into the padding, while being shielded from rainwater. The padding features two sheets of polypropylene, which soaks up and retains oil and oil-based liquids such as lubricants and fuels without absorbing water.

Another feature that field specialists suggested to New Pig is a wrap that allows users to replace the padding but keep the outer plastic shell. That way when the pad gets saturated, the mechanics only have to replace the mat rather than the mat and the shell, which would increase environmental friendliness and lead to cost savings.

Rolling the Products Out to the Field

The substation department began testing the Oil-Only Wrap in spring 2010 and has been keeping the product in stock ever since. The environmental specialists spread the word to supervisors about the new product and made it available for substation employees to try them out at their own stations. Some employees have even chosen to keep them in their vehicles, so they have them on hand.

So far, there have been no challenges when using the wraps. In fact, they have made it much easier for the field workers to manage small leaks. Substation employees simply identify a leak on equipment and then secure the mat around the problem area. The clear plastic coating on the outside of the product gives a visual indication of when the pad needs to be changed. When the bright, white pad absorbs oil, the wrap turns yellow and allows station personnel to see the amount of saturation.

The product comes in two different sizes, but New Pig is able to produce customized sizes for larger or oddly shaped equipment.

Leak Containment

In addition to beta testing the valve wraps, Con Edison environmental specialists also sampled another New Pig product called the Drive-Over Leakblocker Dike. Made out of a patented rubber-like substance, the material can be used on the concrete padding that surrounds transformers to create a barrier between the leaking equipment and the environment. The product is designed to contain small, constant leaks that can't be immediately reached for repair. In the past, the mechanics had to continuously replace absorbent mats to control leaking equipment, but with the Leakblocker, they are able use fewer mats because leaks are contained to the transformer pad. The rubber material is about an inch thick, featuring a durable UV-protective coating and a rounded surface so users can drive or step over it.

Because the rubber is extremely adhesive, users can apply it to almost any clean surface, and it will provide a tight, waterproof seal, which is suitable for leak containment. One problem users previously faced was that the substance would lose its shape in high temperatures and melt to the surface it was on. The Leakblocker, however, has proven to hold its shape in high summer temperatures and effectively contain leaks year round.

When this rubber material originally came on the market, it was available in large square pieces and designed to cover drains and catch basins. The Con Edison specialists, however, discovered an innovative way to use this material by cutting it into long thin strips that could be installed around oil-filled equipment as a means of containment.

Because the wraps and Leakblockers are so easy to use, Con Edison didn't have to offer any formal training on the use of the products and their applications.

The two products have turned out to save both time and money. When equipment can't be immediately taken out of service, field crews can now maintain minor but constant leaks using these new engineering controls from New Pig.

Alexandra Mennella (mennellaa@coned.com) is an environmental specialist with Con Edison in New York, New York. She has been with the company for three years.

Companies mentioned:

Con Edison www.coned.com

New Pig Corp. www.newpig.com/us