"We use a camera system after the line has been jetted and the drain pipes look as good as new," says Bob Garbutt of Pipeline Mechanical. "You can actually read the writing on the walls of the pipe."

Jets do not replace cable machines, rather each complements the other nicely. Each has specific advantages. Jets, for example, handle grease, sand and ice. But to clear heavy stoppages such as tree roots, you'll need a cable machine.

Jets are available in both electric and gas-drive models. The most pressure you can get from an electric jet without worrying about popping breakers is 1,500 psi at about 2 gallons per minute. This combination can handle most inside lines between 1-1/2 inches to 4 inches up to 150 feet long, but is not powerful enough to do a satisfactory job in main lines.

For outside lines up to 10 inches in diameter and up to 600 feet long, a gas-drive jet will provide the pressure and flow rate (3,000 psi at 4 to 5.5 gallons per minute) required to do the job well.

"I rarely use the electric jet any more because the gas jet is so powerful it blows everything away," says George Bauer of Bauer Plumbing. "We'll use the electric on small lines or in an apartment building but we use the gas for everything else -- inside or out."

How does Bauer use a gas jet on an inside job? He leaves the gas jet outside and pulls the jet hose into the basement or up on the roof of the home. He then hooks it up to a portable reel with a smaller diameter hose to handle the inside lines. The exhaust is safely outside while the high pressure of a gas jet is at work inside. Some plumbers mount the jet permanently in their truck and vent the exhaust to the outside.

When you're buying a jet, make sure it has a pulsation device -- it makes the hose vibrate to overcome the friction in the line so the hose will slide easily around bends and go longer distances. Without it, the hose is very likely to get stuck. Your machine should also have a backflow prevention device to prevent sewer water from getting into the fresh water supply. Jet nozzles should be hardened stainless steel rather than brass, as they will last longer and withstand the abuse of cast-iron pipe.

Restaurants, factories and institutions where grease clogs are a constant problem are ideal for jets. If you can set up a maintenance contract with likely customers in your area, the jet can pay for itself in just a few months. Contact the restaurants and tell them you can prevent a clogged drain on a busy Saturday night when the waiting line is out the door. Instead, you come on a slow Monday every other month before the clog occurs.

Greg Collins of Collins Plumbing remembers the time he demonstrated a jet to a customer who thought his restaurant's lines had been cleaned by a cable machine just two weeks before. "We had the head of their maintenance department there, and we pulled out a log of grease probably about an 1-1/2 inches in diameter and about 2 feet long and he was very impressed with that."

Garbutt adds: "Our annual sales from our water jets are approximately $50,000 which is approximately $1,000 gross revenue each week coming off a piece of equipment that we consider to be a very good investment. We've found the need to have a second water jet because we've got a reputation for using this piece of equipment. We used to allow two days to do mains and horizontals in a building. Now we allow one day and charge the same price as two."

A sound investment in any book.

Trouble-Shooting Water Jets