Sewage treatment plant contractor in Philippines and their selection criteria for waste water pumps
With various types of wastewater pumps available, this blog discusses criteria that sewage treatment plant contractor in Philippines uses in selecting the type of wastewater pump. Capital cost, operation and maintenance (O&M) costs, and other relevant criteria are evaluated. The evaluation included investigating wastewater pumping station design and O&M procedures at 15 cities or sanitation agencies in the United States having more than 2,700 pumping stations among them. More than 50 pumping stations were visited and observed.
Sewage treatment plant contractor in Philippines have Several types of wastewater pumps for selection:
Single-stage, dry well, horizontal and vertical configuration (commonly referred to as “conventional” wastewater pumps).
Single stage, wet well, solids handling, submersible pumps. Some submersible motors also are suitable for continuous duty in air for dry well installations.
Single- or two-stage, vertical turbine-type solids handling pumps with driver mounted above grade.
In determining the type of pump to use the sewage treatment plant contractor in Philippines considers, life-cycle economic costs are a major (although not the only) factor for the analysis. Data will be presented in the following sections on estimates for initial construction costs for pumping stations using these three types of pumps and estimates of O&M costs. The data on O&M costs was determined from interviews with users of operating facilities.
Pump Operation Selection:
Submersible Pump- A pump that has its motor and electrical components sealed in a protective housing to permit use under water or other liquid conditions.
Sump Pump- Manufactured to remove unwanted drain water from a basement sump pit and drain tile systems; parking lots and low land areas where lack of a gravity drain allows water to pool. Sump pumps are rated for ground or waste water mostly clear of solids (nothing more than silt and ground water solids less than ¼” diameter). Sewage treatment plant contractor in Philippines mostly install these pumps where basement flooding is a problem, and to remove moisture from around foundations in order to prevent mold/mildew build-up. Discharge pipe size ranges from 1” and up, based on existing drain line applications.
Effluent Pump- Engineered for “gray” water or waste water (mostly liquid) applications that contains solids of ¾” in diameter or less. This is often waste water that has passed through a septic or settling tank and needs to be pumped into an additional system or treatment area. Discharge pipe size ranges from 1 ½” and up, based on existing drain line applications.
Sewage Pump- Mostly used in raw sewage applications or dewatering where up to 2” diameter solids must be passed through the pump. Sewage pumps are often called “ejector pumps” and are used to pump biodegradable waste and water into an existing sewer treatment facility or sewer piping system. Not recommended for household or business that need to pump large amounts of non-biodegradable waste which includes plastics, fibrous materials such as cleaning wipes and hygiene products. Discharge pipe ranges from 2” and up, based on existing sewage pipe drainage applications.
Grinder Pumps- Designed to grind raw sewage material, hygiene products, and non- biodegradable materials more efficiently and into much smaller pieces than standard sewage ejector pumps. Grinder pumps are used in large networks of waste water treatment piping. Typically, these pumps have a bolted flange for a discharge connection, outlet sizes range from 1¼” and up.
Horsepower Selection
When selecting the horsepower of a submersible pump there are two main factors that should be considered by sewage treatment plant contractor in Philippines: GPM and Total Head.
GPM- Gallons of liquid A pump can remove per minute at the specified head limit.
Total Head (head pressure)- Total maximum height at which a pump can perform before it begins to lose flow. Typically, the higher the horsepower, the more powerful the pump will be. The higher the increment of horsepower typically means the pump will have a higher Total Head and GPM. This makes it possible to pump over long distances in a pressurized non-gravity fed system. A residential application requires the measurement from the bottom of the collection pit to the point where gravity takes over and the liquid can freely flow. Typically, this gravity point is a turn to exit the home or a connection to a larger drain pipe.
Example: A basement with the pump emptying into the drainage system just above 8’ ceilings and a pit that is 18” deep will have a measurement of 114” or 9 ½’ of head needed by the pump to perform at its specified GPM.
Most sump pumps require a motor range of 3/10hp and up for residential or light commercial/industrial applications. Knowing the flow into the pit is important and can be estimated by the simple equation below. Remember, the GPM of the chosen pump must be larger than the GPM into the pit or the pump will not keep up.
Sandy soil- Basement’s square footage divided by 100 and multiplied by 2.50 equals GPM
(i.e., basement’s sq. ft./100 x 2.50 + GPM)
Clay soil- Basement’s square footage divided by 100 and multiplied by 1.25 equals GPM
(i.e., basement’s sq. ft./100 x 1.25 = GPM)
Effluent, sewage ejection and grinder pumps start at 4/10hp through 2hp and up for the grinding and solids transfer capabilities. Typically, they are a higher horsepower than residential sump pumps. Sewage treatment plant contractor in Philippines that it is important to know the maximum head limit and the amount of water being pumped per cycle (collection pit gallon rating) when choosing horsepower for a submersible pump.
