Choosing a Wildfire Pump
4 February 2024Continuing with my focus on improving wildfire response I have put together some information on choosing the right pump for you as you start purchasing your fire suppression tools or upgrade your current systems. The information is based on my experience and research. I am not a water delivery expert and every situation requires specific requirements that may be vary from those detailed below. Don’t sue me. Your lawyer will be disappointed.
It is critical that water delivery systems provide adequate water to the fire when needed. Pumps are like first aid kits; they sit unused year after year but when you need them they have to be up to the task.
If you are purchasing water delivery equipment for the first time do an assessment of your needs and design a system that will work for your situations. You may need to meet specific legal requirements or may be choosing a system to protect your assets and values.
If you already have a water deliver system review it. Consider the recent extreme fire behavior we have experienced and upgrade your pumping capacity as required.
An off the rack pump that produces 45 to 65 psi. will not deliver adequate water for more than one or two hose lengths (max 200 ft) especially if pumping up hill.
Two- Stroke or Four Stroke
Two strokes and four strokes both have advantages and disadvantages.
Two strokes can run in any position, have a higher shaft speed but can be finicky to operate. The external fuel tank allows for up to 5 hours of run time.
Waterax Mark 3 – Two Stroke 380 psi
Four -strokes are more common and people are familiar with their operation. They need to be level to operate. The internal fuel tank only allows for +/- 1 hour of run time.
Waterax Striker Four Stroke 380 psi
Pump Type
Almost all pumps used in wildfire suppressions are centrifugal pumps.
Self-priming pumps are easier to operate but you won’t be able to use them in tandem or in multi-pump systems.
High pressure pumps specifically designed for wildfire use usually need to be hand primed but can be hooked together in tandem to produce very high pressures.
Pressure pumps produce relatively higher pressures but deliver lower flows and are designed for moving water distances.
Volume pumps produce relatively lower pressures but deliver higher flows and are designed for moving higher volumes of water shorter distances. (eg: refilling portable tanks)
Wildfire Act and Regulations for Industrial Operations
Any industrial operation doing “High Risk” work as described in the Wildfire Act (Part 1 “definitions”) needs to have a water delivery system on site. Part 2, Div 2, Section 6 (3) (ii) describes the requirement for an “adequate fire suppression system”. https://www.bclaws.gov.bc.ca/civix/document/id/complete/statreg/11_38_2005#section1
The Act and Regs leave it to us to decide what is “adequate”. An Interpretive Bulletin in 2011 tried to give guidance:
The Bulletin doesn’t give any advice regarding pump pressure but says the system must produce “water at an effective nozzle pressure of a minimum of 25 psi through a standard 9.50 mm straight bore nozzle opening for 50 minutes….”
I suggest 30 psi at the nozzle is a better minimum standard.
Pump Pressure Review
Water delivery systems lose:
½ psi for every vertical foot uphill (will gain this pressure if pumping downhill).
+/- 4 psi per 100’ length of 1 ½” on flat ground
+/- 17psi to 27 psi psi per 100′ length on slopes
30 to 50 psi per sprinkler
+/- 5 psi per valve/appliance
We seldom have too much water or too high a pressure when working on wildland fires. More is almost always better. Use 30 psi per nozzle as the minimum.
Assess Your Needs
1. How valuable is what I am trying to protect?
2. Am I able to deliver water everywhere in my area of concern with a vehicle and portable tank (skidder, water truck, pickup)?
Barr Plastics Fire Suppression Trailer
3. How far do I need to pump and is it up hill or down?
4. Am I going to need to insert “kicker” pumps to achieve the required pressure?
Multi-pump System
5. How many nozzles or sprinklers will I be operating at the same time?
6. Is the pump for short term emergency use on a variety of sites, extended periods of active wildfire suppression or static value protection? Am I going to be able to re-fuel it at the required interval?
7. Is my water source adequate to supply the required pressure and volume?
Industries such as logging that work on various sites should plan for the most difficult possible conditions. Uphill pumping on long, steep slopes with limited access is common. High pressure pumps will likely be required.
If you are setting up a system for use around a specific location you can do a more detailed needs analysis.
Work Back from the Nozzles to Estimate the Required Pressure
No. of nozzles x 30 psi
= _____
No of sprinklers x 50 psi
= _____
Elev. Gain/Loss in ft (___) x .5 psi
= _____
No. of 100 ft sections of 1 ½ “hose (__) x 4 psi
= ______
No.of valves and fittings (___) x 5psi
= _____
Example Estimate
No. of nozzles (2) x 30 psi
= 60
No of sprinklers (0) x 50 psi
= 0
Elev. Gain in ft (200) x .5 psi
= 100
No. of 100 ft sections of 1 ½ “hose (5) x 4 psi = 20
No. of valves and fittings (6) x 5psi
= 30
Total Required minimum Pump Pressure
= 210 psi
Conclusion
Not all pumps are created equal.
Considering recent fire behavior you may want to upgrade your pumps as part of your replacement program.
Know your legal obligations for water delivery on industrial sites.
Assess what you need and consider the value of what you are trying to protect.
Don’t scrimp when purchasing pumps.
If you can get portable tanks to the fire site lower pressure pumps will do the job.
It is always better to have more pressure than you need.
Give me a call anytime if you need a hand assessing your requirements for a water delivery system.
I am working on developing a Pumps and Pumping Course for Industry and Rural landowners. Stay tuned.
Let me know what you think of the above information, especially if you disagree with any of the content or have additional information.
Talk soon.
Doug