Pumping In Pressure on The Fire Ground (Pump Series - Part 7)

Last week we talked about pumping in Volume (or Parallel). Today we are going to look at the second FUNCTION our pumps are capable of - running in Series (or in Pressure)
When our two-stage pump is running in series, the two impellers have now “aligned,” or been “stacked.” Again we use these phrases to help you visualize the function, not describe the actual anatomy of the pump.
As water (volume) enters the intake side of our pump it is now routed (via the transfer valve and two flapper valves that close) from one impeller into the eye of the second impeller. As velocity is induced (via the first stages’ impeller) to our volume, it leaves the first stage of our pump with greater pressure. As it enters the second stage (the eye of the second impeller) additional velocity induced generates additional pressure as it leaves the second stage of our pump resulting in greater discharge pressures than if we ran in parallel.
Whereas the stages of our pump were working independently in parallel, now our stages are working in a series… one feeding the next.
As a FORCE MULTIPLIER, Series allows us to take the already pressurized water source (the municipal water system via hydrant) and add TWO levels of pressure increase to the discharged volume.
Scenario Example:
If impeller #1 produces 500gpm @ 100psi,
Then impeller #2 increases the original 500gpm another 100psi
Combined they produce 500gpm @ 200psi
✅To view extended training content for this video on w The Roll Steady website, visit - bit.ly/trsposts
✅Subscribe to help support this channel and get updates as content is added - bit.ly/trssubs...
I hope this video, 1) helps you become more confident in your craft of Firefighting, and 2) Sparks a conversation with your crew and Officers.
Want to help support this channel? Please hit the CZcams Subscribe button AND join the conversation in the Comment Section below.
More to come next week. Until then... Roll Steady.
---
👍🏽RECOMMENDED PLAYLISTS:
✅ Driver Engineer - • Dallas Fire Department...
✅Nozzle Man - / playlist
list=PLV5UfqoDi7nNUTwFWbck7MeuiY54whbpK
✅Plug Man - • Dallas Fire Department...
✅Ground Ladders - • Firefighter Ground Lad...
🎥THE GEAR I USE:
I shoot content on #gopro & #Sony #AlphaFamily Cameras. My Content Creation Side Hustle is Thirty2 Pixels - www.vimeo.com/t...
👍🏽FIND ME ON SOCIAL MEDIA:
✔️Facebook - / greglackey
✔️Twitter - / therollsteady
✔️LinkedIn - / therollsteady
✔️Instagram - / therollsteady
🚨DISCLAIMER:
Dallas Fire-Rescue does not endorse or promote [most of] these videos. I am an adjunct instructor that does produce content specifically for the Department on occasion that is posted here as well. However, these videos are for educational purposes only. Always talk with your Officer and crew before implementing anything you see here on The Roll Steady.

[@Aviation2016]

Thank you for the videos. Going through driver op, pumper, and aerial. It says you have videos that are hidden. Do Those videos have good info?

[@codylanders5014]

Can you give me scenarios as to when you would pump in pressure as to when you would pump in volume? Great video series, great information!

[@TheRollSteady]

Pumping in Volume and and Pressure are the two modes offered on a dual stage pump in order to optimize flow from your engine. At lower volumes, pumping in pressure is more efficient. Yet, once you begin to reach 1/2 the rated capacity of your pump, the engine’s pump will become more efficient in volume.
Most often people want to know when to switch to Volume, since Pressure is the default… here are a couple:
1. You are flowing greater than 1/2 your rated capacity (see new video I just posted on this). Big fire = big water = volume.
2. You have a “hot plug” and your intake pressure from that hydrant is causing your baseline discharge pressure to be higher than your first lines PDP. Switching to volume is a trick you can use instead of gating your initial handline down. This happens a lot on our Pierce Engines in Dallas that run SB nozzles that require lower pressures.
3. You know you’re going to relay pump. Initial volume might not meet #1 criteria, but I would anticipate larger flows and make that transition early rather than later.
Just a couple times I would in an urban environment.

[@batcitytrailrider4704]

Are most engine/quint pumps single stage or dual stage? Sorry if that seems like a basic question. Up on the pump panel is selecting pressure or gpm different from doing it from a labeled transfer valve like shown in the thumbnail of this video? I was recently told our pumps are single state, but I thought they were dual since up on the panel we could select pressure or rpm - or is that just for the governor? Thanks so much love the channel!