Have a flow test in a semi-rural area that has static pressures of over 130 psi but a residual pressure of 60 psi at just 500 gpm.
A flow test from nearly a decade ago shows worse results - with a static of around 120 and a residual of 20 psi at just 600 gpm.
My initial concern with the older flow test was a partially-closed valve or obstruction in the line.
With the newer test the residual pressure seems more reasonable, but other than something being wrong with the system is there a reason that would justify a residual pressure less than half the static at only 500 gpm of flow? Perhaps a system fed with small pumps and no tower? What are your thoughts?
Posted anonymously for discussion. Discuss This | Submit Your Question | Subscribe
Subscribe and learn something new each day:
Thank You to Our Top
October '20 Contributors!
Sprinkler Designer or Engineer?
Get all of our tools, including the Sprinkler Database, Friction Loss Calculator, Fire Pump Analyzer and more:
Daily discussions are open-ended fire protection, fire alarm, and life safety questions submitted anonymously for the benefit of sharing expertise and learning from other perspectives. Anyone can submit a question here:
2020 PE Prep Guide
PE Prep Series
2020 PE Prep Series
(Click to enlarge)
Visit July-October for daily Fire Protection PE Exam sample questions.
Solutions are posted the day after posting.
Comment with your solutions, questions or clarifications.
Please note that questions posted are unofficial and in accordance with NCEES rules are intended to be similar to actual exam questions, not actual exam questions themselves.