Specifying Domestic Water Booster Pumps
by GREG CUNNIFF, PE, Taco inc., Cranston, RI
In tall buildings the pressure provided by a municipal water system is generally not sufficient to provide adequate pressure at the top of the building. As an example, municipal water systems typically provide maximum pressures in the range of 100 to 150 psi. This translates to buildings of 20 to 30 stories. Above this height the building will require a domestic water pressure booster system.
If a booster system is employed then the next issue to address is how to supply a substantially varying flow rate with relatively constant flow rate pumps. To accomplish these tasks the industry has utilized several types of pressure booster systems. They can be loosely categorized as follows:
1. Open tank storage systems.
2. Closed tank hydropneumatic systems.
3. Tankless systems – constant volume pumps.
4. Tankless systems – variable volume pumps.
Open tank storage systems utilize an open atmospheric tank located at the top of the building. These kinds of systems are the simplest in terms of pump control. The pump operation is controlled by a simple level control in the tank. The tank volume and pump flow rate are typically sized to prevent short cycling of the pump.
Since the tank is open to …MORE
Click here or on the photo for a PDF of the article from the June 2008 issue of Plumbing Engineer magazine.