While modern technologies like video inspection may be able to help plumbers and public safety officials identify blockages in pipes and sewer lines, they don’t do much to pinpoint problems that are related to inflow and infiltration. Nearly two-thirds of potentially contaminated storm water and wastewater enters sewer lines through collateral conduits that city planners may not even have known were connected to the sewer lines. A sewer smoke test can help public safety officials discover breaches in closed systems that could be connected to leaks, rodent entry points, and noxious, potentially harmful gases.
What Equipment Does Smoke-Testing Require?
Smoke testing is a relatively simple process. It requires two types of equipment:
• A smoke source: A number of commercial products are available for smoke-testing sewer lines. They fall into two categories: smoke candles and smoke fluid. Smoke candles are engineered to produce a consistent flow of nontoxic vapor that is dense and white while smoke fluid is a petroleum byproduct.
• A blower: Once the smoke is produced, it is typically blown into a manhole. The smoke will then follow the path of least resistance, resurfacing from sites like broken manholes, cracked pipes, uncapped lines, sump pumps and yard drains. This flow can be hampered if the smoke is competing with falling rain, so smoke testing is best carried out in dry weather. Additionally, most blowers are customized to work with specific smoke sources, although a few blowers engineered to work with both smoke candles and smoke fluid have begun to hit the market.
Which Smoke Source Is Best?
Smoke candles and smoke fluid are both efficient smoke generators for testing needs. They have significant differences from one another, however, which may make one a better choice given your own preferences.
• Cost: Blowers designed to work with smoke candles are typically less expensive than other types of blowers. However the cost-per-minute expenses associated with smoke fluid are lower.
• Smoke density: The smoke produced by candles is noticeably denser, which means it can be tracked from farther away.
• Convenience: Smoke fluid is easier to use because candles only give out smoke for three minutes after which you must go to the trouble of programming your blower to handle a new smoke candle.