The Basics of Series/Relay Pumping (Pump Series Part 25)

[@anwarrior0152]

Awesome video..just subscribed..keep em coming

[@dzuythan826]

Love the information and love the delivery. If possible, please turn down the music to all videos, if not at least the newer videos. Keep up the great work!

[@paulalva2381]

I have a question! I was taught that when relay pumping, you should have your governor set to rpm mode. Wouldn’t you still be able to make it work in psi mode? What’s the benefit as the relay pumper of being in rpm mode?

[@TheRollSteady]

Paul, do me a favor and ask this same question over at Rollsteady.com. Two guys in particular - @nickmartin, and @chrispace are going to give you a much better answers that I can here. My experience with engines that have a pressure gov and psi/rpm mode is limited.

[@bfdchief115]

Quick question, when relay pumping should the supply engine be in pressure or volume for a two-stage pump?

[@TheRollSteady]

It really depends. What are you discharging (GPM) from the attack pumper?

[@bfdchief115]

@@TheRollSteady That’s what I figured. So if the attack engine is discharging high volume supply engine pumps in volume, and if you’re just flowing one or two Crosslays you could stay in pressure?

[@TheRollSteady]

Some have a hard and fast rule. I look at it from an pump efficiency perspective.

[@Thesegul]

I can only imagine the "intake to intake" line cavitating. Isn't that a possibility? Also how do you safely simulate the engine running out of fuel without harming the engine?

[@TheRollSteady]

Sorry for the delay. Both engines are sharing the same hydrant (and its pressure). Cavitation would look very similar for either apparatus.

[@67NewEngland]

How about a hydrant assist valve. That way if the boosting supply engine fails you can at least get water to the attack engine with a simple turn of a handle.

[@TheRollSteady]

Help me out with the hydrant assist valve. I’m not familiar with that.

[@shawnmorrison7882]

​@@TheRollSteady Humat Valve , zero interruption of water supply to bring water into second pumper to boost pressure.

[@bendone1965]

If the pump fails on Engine A the water will still pass through to Engine B, it just wont have the added pressure of Engine A's pump

[@TheRollSteady]

Thanks for the comment. You are correct that under most circumstances water will continue to pass through without added pressure if Engine A's pump fails. A good example of this is demonstrated when we teach rookies how to pump through an engine that has run out of fuel. However, it is possible, and has happened here in Dallas (Baby Does Fire for example), that the discharge side of the pump was rendered useless - completely occluded. This is referred to as a "catastrophic pump failure."

[@lisaball1701]

How does Intake to Intake bypass the pump? I’m kinda confused here. Is there an explanation of this concept explained somewhere?

[@TheRollSteady]

@@lisaball1701 pretty sure I've seen ya on The Roll Steady network, right? If so I have a pretty lengthy article on there that maps this out. You can also look up on our YT page an earlier video in this series that discusses the Intake Manifold.

[@TheRollSteady]

@@lisaball1701 www.therollsteady.com/posts/pump-series-part-24-dualparallel-pumping-basics

[@TheRollSteady]

@@lisaball1701 and ... kzbin.info/www/bejne/bJevhZunrNmDd7c