Letters to the Editor: December 2020
Read some thoughts from our readers from December 2020, including responses to Bobby Halton's editorial and Jerry Knapp's piece on engine work.
friction loss
The Latest
Pressure and Flow Without Numbers
You don’t need to do the math or know the precise numbers to know whether your hose stream is sufficiently pressured, writes Alex Degnan.
Fireground Pump Operations: Mastering the Panel
Paul Watlington looks at some of the factors effective drivers/operators must deal with when it comes to fulfilling this critical fireground function.
Preplanning: Include the Hose Stretch
Anthony Rowett explains why and how to incorporate into a building’s preplan the specifics pertaining to initiating the initial hoseline should a fire occur in that structure.
More friction loss
Bringing the Medium-Diameter Line Back into the Mainstream
By pinpointing past failures and addressing common issues head on, successful 2½-inch handline deployments will undoubtedly follow.
Deck Guns: Know Your Flow
Joseph R. Polenzani explains how to get the most exact flow reading from the apparatus-mounted deck gun.
Water Delivery for the Rural Engine Company
Richard Ray offers these best practices for getting water on the fire in a rural setting.
Developing Accurate Pump Discharge Pressures
Paul Shapiro explains the processes for determining accurate pump discharge pressures using a flowmeter, an inline pressure gauge, and a handheld pitot gauge and offers tips for expediting calculations on the fireground and developing reference charts.
Friction Loss Rules of Thumb
Knowing the thought process behind what the pump operator is calculating is as important as being able to plug numbers into the formulas to obtain an answer, writes Paul Spurgeon.
HAND METHOD FOR CALCULATING FRICTION LOSS IN THREE-INCH HOSE
When it comes to supply-ing hoselines on the fireground, we all can handle the standard configurations.
Friction Loss for 1 3/4-Inch Hose
The 1 3/4-inch has some advantages over the 1 1/2-inch line, among them larger gpm flows, less friction loss, and less pump discharge pressure needed.
Universal Friction Loss Formula
Most fire science students and pump operators eventually become familiar with the given formula used in determining engine discharge pressure for a given hose layout: EP = NP + FL + BP Where: EP = engine pressure (pump discharge)