RAW SEWAGE PUMPING STATIONS OF WASTEWATER TREATMENT SUPPLIERS
If you browse through the list of wastewater treatment suppliers in Philippines, the sewage pumping stations are used by them only where necessary. Pumping stations shall be protected from physical damage and remain fully operational during a 100-year frequency flood. Wherever possible, pump stations for small-scale installation shall be constructed without a superstructure. Pumping stations shall be readily accessible during all weather conditions.
wastewater treatment suppliers criteria of pumps ?
Submersible pumps shall be used whenever possible. Manholes over pumps shall be of a size that will permit removal of pumps via slide-rails without entering the pump chamber. Minimum access diameter of 24 inches (61 cm) shall be provided. Wet wells shall be vented to the atmosphere by means of a vent pipe, extending not less than 15 feet (4.57 m) above the finish grade, attached to a utility pole, or adjacent building, or other appropriate structure. Centrifugal, suction head pumps are allowed provided the pump station consists of separate wet and dry well.
What shall be the Capacity?
The working capacity (between pump-on and pump-off) should provide a holding period not to exceed 10 minutes for the average daily design flow. All pump stations shall have an emergency storage capacity (above the working level) of 6 hours without overflowing or causing backups.
What is the Pump Type?
Submersible pumps shall be designed specifically for submerged use in raw sewage. An effective method to detect shaft seal failure or potential seal failure shall be provided. Pumps shall be capable of passing spheres of at least 3 inches (7.62 cm) in diameter. Pump suction and discharge openings shall be at least 4 inches (10.2 cm) in diameter. A full description of the pumps including pump curves shall be provided in the specifications. Discharge openings of 2 inches (5.08 cm) will be allowed in the case of grinder pumps.
What are the conditions for Pump Removal?
Submersible pumps shall be readily removable and replaceable without dewatering the wet well or disconnecting any piping in the wet well. Pumps shall be mounted on a slide rail for easy removal.
Do we need Duplicate Pumps?
Duplicate pumping equipment shall be provided. If only two pumps are provided, either shall be capable of handling peak design flows. Where three or more pumps are provided, they shall be designed to fit actual flow conditions and must be so designed so that with any one pump out of service the remaining pumps will have capacity to pump peak design flows.
What type of Level Controls is required?
A walk through the list of wastewater treatment suppliers in Philippines shows that Level sensing devices shall be located in the wet well so as not to be unduly affected by flows entering the chamber or by the suction of the pumps. Provisions shall be made to automatically alternate the pumps in use. Please see the chapter on Instrumentation Guidance for additional detail.
What are the alarms activation requirements?
An alarm system shall be provided for all pump stations. The alarm shall be activated in any one of the following cases:
low water in the wet wells
high water in the wet well;
loss of one or more phases of power supply;
loss of the alarm transmission line; or
pump failure.
The alarm shall signal at the treatment plant and a facility that is manned 24 hours a day. An automatic dial up capable of dialing several numbers will be accepted as an alternative to the secondary alarm at a manned facility. Please see the chapter on Instrumentation Guidance for additional detail.
What type of Valves should be used?
Suitable shut-off valves shall be placed on the discharge lines of each submersible pump. A suitable check valve shall be placed on a horizontal section of each discharge line between the shut-off valve and the pump. A valve pit outside of the wet well shall be provided and this is mentioned in the list of wastewater treatment suppliers in Philippines.
