How Pressure Data Evolves Flow Management
April 5, 2019
Presented by: Bob Beers
Learn all about the relationship between pressure in a mainline and how changes in PSI can influence downstream flow rates. Presented by Bob Beers (and Chris Wright) of Baseline, this webinar will review several solutions to for capturing PSI readings within a hydraulic structure. You'll also pick up some valuable tips on how to manage those configurations as intelligently as possible.
Webinar Contents:
Note: The following catalog of content covered in this webinar is time stamped to allow you to follow along or skip to sections of the video that are relevant to your questions. You can also search for content on this page using the FIND command in your browser (CTRL + F in Windows, Command + F in Mac OS.)
- Intro/TOC
- Understanding Pressure in Water Management
- Why Do We Care About It?
- How Can We Use Pressure Data to Be More Efficient?
- What Solutions Are Available to Manage
- Pressure Data and System Operations?
0:00 – 4:10: Intro/TOC
4:11 – 10:23: Understanding Pressure in Water Management
What does PSI have to do with flow rates? (4:11)
It’s all in the physics! (8:00)
With an increase in flow rate, the velocity of the fluid increases. With the increase of velocity, the pressure decreases (Bernoulli’s Theorem). Therefore, increasing flow decreases pressure.
Impact on system hydraulics (9:02)
- Too much flow leads to water hammer because water is not compressible.
- Increased flow leads to turbulence, resulting in pressure loss.
10:24 – 14:38: Why Do We Care About It?
Excessive pressure can rupture mainlines and hinder the performance of sprinkler heads, causing misting.
Why is understanding pressure important? (11:24)
Understanding your site (11:29)
- Flow rates
- Distribution uniformity
- Irrigation efficiency
- Water windows
- Equipment on site
Factors that influence pressure in a system (12:25)
- Changes in topography
- Friction loss
- Turbulence in flow
- Velocity
What happens if pressure (PSI) is not managed properly? (13:28)
Common symptoms of high pressure (PSI):
- Catastrophic mainline break
- Misting
- High equipment turnover
Common symptoms of low pressure (PSI):
- Damage to softscape due to water pooling
- Damage to softscape due t lack of sufficient coverage
14:39 – 17:20: How Can We Use Pressure Data to Be More Efficient?
What does pressure (PSI) have to do with flow rates? (14:39)
Impact on system performance:
“Myth Busters”: WaterSmart Irrigation Expo 2008: A +/- 10 PSI pressure change in an irrigation system will significantly impact the distribution uniformity of a zone, resulting in a 40% change in the amount of water needing to be applied to achieve plant water management.
Benefits of managing pressure in a system properly (16:05):
- Improved water management efficiencies
- Improved health of landscape
- Improved longevity of hardscape
- Protection from catastrophic system failures
17:21 – end: What Solutions Are Available to Manage Pressure Data and System Operations?
Hardware solutions (18:00)
Static meters (18:50)
Great for:
- Capturing pressure data
- Monitoring pressure (PSI) readings
Downsides:
- All readings are manual
- No alerts
- No automation
2-wire solutions (19:28)
Great for:
- Capturing pressure data
- Pushing alerts, system automation
Downsides:
- Depend on 2-wire system integrity
- Require a control system
Example configuration (20:21)
All-in-one solutions (25:20)
- Flow sensor
- Master valve control
- Pressure sensor
Results (26:35):
- Alerts
- System shutdown
- Leak detection
- Flow optimization
Cloud-based solutions (28:05)
Features:
- Alerts
- System shutdown
- Leak detection
- Flow optimization
Benefits:
- Real-time pressure (PSI)
- Real-time flow (GPM)
- Historical data
- Messages and alerts
Summary (33:45)
- Improved water management efficiencies
- Protection from catastrophic system failures
- Automated
Contact info:
Chris Wright: Baseline Vice President of Sales
+1 801-349-9803
Bob Beers
Baseline Product Manager, Irrigation Technology
+1 208-639-8738
Question: What is is the relationship between static pressure and the watering window? (35:55)
Answer: There isn’t a direct relationship between static pressure and the watering window. The relationship is between flow rates and watering window. If you have an undersize mainline that isn’t providing a sufficient flow rate to operate the system within a given water window, it can create an issue. If you have an undersize mainline, not enough flow rate, and excessively high pressure, it will compound the issue and create other issues with turbulence in the system.
Question: Is there a way to calculate water velocity? (37:29)
Answer: Formulas exist for this if you know your pipe size and your pressure through a static pressure gauge. You can find the formulas online, as well as charts for a quick estimate. The beauty of this pressure transducer technology is that the transducer doesn’t have to be associated with a master valves or flow sensor. It can be installed at any point on a mailing or lateral line where you may want data to help manage the system. You can use the pressure reading in real time to determine the operation of any components downstream, based on where it’s installed. For example, if you have an elevation change on your site, you can install a transducer at either the top or the bottom and create operational delays based on its readings upstream or downstream.
Question: Can you comment on your preference of manufacturer in regards to flow sensors, master valves, or controllers, and why? (41:08)
Answer: Baseline doesn’t have a specific manufacturer preference, although some manufacturers have Baseline decoders integrated into their flow sensors and master valves. Baseline decoders can interface with any flow sensor that provides output, as well as any master valve.
Question: Is there a minimum distance between assembly pressure sensors, master valves, and flow meters to allow for access from either a maintenance or general operation standpoint? (43:08)
Answer: The distance requirements will depend on the pipe diameter of the system and how you want to manage it.