Metal Bevel Gears,Precision Parts Bevel Gears,Bevel Gears,Customizable Bevel Gears Jiangsu Juli Gear Co., Ltd. , https://www.spiral-bevelgear.com
Drainage pumps used in buildings include submersible sewage pumps, submersible drainage pumps, vertical sewage pumps, and horizontal sewage pumps. Due to the limited space available in most building sites and the relatively small flow requirements, submersible sewage and drainage pumps are typically preferred. Submersible sewage pumps are often used in critical areas, while vertical and horizontal sewage pumps require additional space for installation, earthquake resistance, self-priming, and may not be as commonly used in standard building applications.
When selecting the flow rate of a drainage pump, it should be based on the design second flow for daily drainage. For adjustments in flow, the maximum hourly drainage flow should be considered. Fire elevator pit drainage pumps must have a flow rate of at least 10 L/s. The head of the drainage pump is determined by the lifting height and pipe losses, with an additional free head of 0.02–0.03 MPa added. The flow velocity in the suction and discharge pipes should not be less than 0.7 m/s or exceed 2.0 m/s.
In public buildings, each living drainage tank should be equipped with a backup pump, and these pumps should operate alternately. In basements, equipment rooms, and garages where floor flushing is required, at least two drainage pumps should be installed. If the catchment area cannot accommodate an emergency drain, the pump should have an uninterrupted power supply. However, if the drainage pipe can be closed, an uninterruptible power supply may not be necessary, but an alarm system should still be in place.
When handling sewage with large debris, the outlet pipes from submersible sewage pumps in different sumps should not be merged. For general wastewater, the discharge pipes may be combined depending on site conditions. When two or more pumps share a single discharge pipe, a valve and check valve should be installed on each pump’s outlet. A check valve should also be installed to prevent backflow. It is not allowed to mix pressure drainage with gravity drainage systems.
If the submersible sewage pump is handling large debris, it should be equipped with a shredding device. For wastewater containing more fibrous materials, a larger submersible sewage pump is recommended. If the motor power is 7.5 kW or higher, or the outlet diameter is DN100 or larger, the pump should use a fixed auto-coupling device. For smaller pumps, a mobile installation method is acceptable. In sewage collection pits, submersible sewage pumps should be equipped with fixed auto-coupling devices for easier maintenance.
Drainage pumps should be capable of automatic start and stop, as well as manual operation on-site. Multiple pumps can operate in parallel and alternate, or be activated in stages depending on demand.
October 01, 2025