We understand that the best way to determine the flow rate of an operating pump is the proper readout of gauges attached to the pump …
Net Positive Suction Head (NPSH) Part 5 of 5 – Good Cooling Tower Pump Piping Practice
Happy New Year 2021! I pray that we all have a healthy year and see the return of normal lifestyles. This final blog in this …
Net Positive Suction Head (NPSH) Part 4 of 5 – Gauge Readings
The cooling tower pump calculations are completed, the project is bid, the Bell & Gossett pumps scheduled are awarded and installed. There is a noise …
Net Positive Suction Head (NPSH) Part 3 of 5 –NPSH Available
The available cooling tower pump NPSH or net positive suction head is a function of the pan elevation, friction, and temperature. Sometimes the combination of …
Net Positive Suction Head (NPSH) Part 2 of 5 –Safety Factors
The Hydraulic Institute (HI) is a global authority on pumps and pumping systems. Think of them as the ASHRAE of pump design and testing. HI, …
Net Positive Suction Head (NPSH) Part 1 of 5 – Terms and Definitions
One of the most misunderstood concepts in pump selection for hydronic design is the net positive suction head or NPSH. Problems with NPSH can spell …
Create a New Variable Speed Pump Control Curve after Hydronic Balancing
This week, the R. L. Deppmann Monday Morning Minutes will explain how to show multiple speeds on a pump curve and how to determine what …
Hydronic Pump Balance using the Variable Speed Drive (VFD) with No Balance Valve on Pump
When there is no hydronic pump discharge balance valve, the variable frequency drive (VFD) is an important part of the balance procedure. How does the …
Hydronic Pump Balance using the Variable Speed Drive (VFD) with Assistance from a Triple Duty Valve
Most centrifugal pumps in heating and cooling systems have some oversizing in the head calculation. Once the HVAC hydronic system is proportionally balanced per ASHRAE …
Open Cooling Tower System Pumps – Balancing the Pump Using a Drive
Open cooling tower pumps are traditionally operated as constant speed. When balanced, the extra pump head or over-heading is throttled across the discharge balance valve …