A few decades ago, well, definitely not more than four, a contractor was introduced to electric powered submersible pumps. The crew’s first reaction was, “What! You’re going to throw that electric motor in the water? You’ve got to be crazy!” After a few weeks of getting comfortable with the subs, the whole crew was handling them like they were born to it. In the years since, submersibles have become commonplace at construction jobsites, in residential basements, plants, backyard ponds, and at innumerable pumping locations throughout the world. The reason is that “subs” are all push, no pull. No suction hoses required. The only weakness that subs have is heat tolerance; however, as long as air or water is going through the pump case the oil bath-cooled mechanical seal, which is now usually made of tungsten carbide or silicon carbide, will live.
the sub is the “wet” pump handling the ground water or effluent. The sub can pump in any orientation, either lying on the ground on its side, standing up, or even upside down. Lying sideways makes the pump easy to manipulate by hand. Subs can be outfitted with suction and discharge adapters with grooved restrained-joint connectors so that the pump can be slid into a piping line without moving the piping. In that way, if the pump has to be taken out for service or repair, another pump can be immediately dropped into that position without reconfiguring the plumbing and without a hoist or machine. To protect floor finishes from vibration or scuffing damage, a polyethylene or polypropylene sheet can be placed under the pump.using a suction manifold and a discharge manifold allows multiple pumps to be used in parallel. Being electric powered these pumps can then be controlled by sensors or floats so that as the flow requirement increases or decreases, more or fewer pumps can be brought on-line or dropped off-line automatically. With the addition of communication hardware, i.e., a mobile telephone, if a malfunction or change in status occurs any number of persons can be alerted automatically. Transmitters can also relay pertinent information like flow rates, component temperatures, system vacuum levels, or discharge pressures continuously or at predetermined reporting times to a monitoring Web site. one operator can monitor multiple pump sites simultaneously from anywhere in the world.The components that make this type of pump station possible are the vacuum-priming pump and the air-water separator. The priming pump, usually a liquid-ring or rotary.
This compact, simple design has more applications than most people are aware of and not all involve submergence. Besides being used in the typical sump pump configuration, “subs” can be used as “out of water” in-line booster pumps, mixing pumps, aerators, and agitators, and also as the “wet” component of a vacuum-primed, dewatering, or bypass system, either singularly or in multiples, either in parallel or in tandem.As part of a vacuum-primed, dewatering, or bypass pumping system, submersibles fit into tight places where other pumps won’t go, and up to 15 horsepower, can be put there by hand. As one of the three primary components of a dewatering or bypass system pumping station, the “wet” pump, the “dry” or priming pump, and the air-water separator vane vacuum pump, can be set up remotely several hundred feet away from the dewatering or bypass system and can be set at any elevation. The air-water separator, available in aluminum for ease of handling, is situated at the submersible pump for efficiency. This device allows the air and gases, but not the water, to be drawn off the system by the vacuum pump keeping the sub, the “wet” pump, primed. one of the nice features of this setup is that since the “wet” pump is already a submersible, if the area becomes flooded for any reason, the pump and dewatering or bypass system won’t be damaged and can still function to help control the flooding, maintain the dewatered condition, or maintain the bypass operation during the flood. Conversely, if the system runs dry, the oil bath in the sub will protect the seal until fluid flow returns.
SUCCESS IS SAFETY
As with any pump system the key to success is SAFETY. Subs are usually electric powered although hydraulic powered subs are also a popular alternative. In either case, the operator must be cognizant of the dangers of working around electricity or high pressure. When working with electric powered subs in wet areas, particularly excavations or basements, it’s a good idea to wear lineman’s gloves and rubber boots when handling the pumps. The crewman should ALWAYS carry a meter to check for voltage before touching the pump to move it or work on it. Use proper Lockout-Tagout procedures before disconnecting the power supply. oh, and most importantly, NeVer use the power cord as the tag line to pull or lift the pump. It’s a power cord NoT a rope