Supply Line Accumulator

[Back Forty]

I want to run an accumulator where the engine coolant supply line exits my berkley pump to knock down some transients that popped a line last year. Is anyone running something like this? I know the aluminum hull guys are always out of the water. What are they doing? I will admit to running the old run-about fairly hard and will unload the pump quite often. After a rebuild this spring, I want to surpress some of this "spike" problem. This seems to be what pops intake gaskets quite a bit around here.
If nothing exists, I will run a smaller fire extinguisher canister upside down, striped and polished with some machined brackets. Should do the trick and look nice with some aeroquip work.
Anybody?

[MudPumper]

Why would you want to knock down homeless people????

[moneysucker]

Originally posted by MudPumper
Why would you want to knock down homeless people????
My thoughts exactly!
I run A ball valve. This months jet tech says not to though, Or you could use some kind of pressure regulator.

[Back Forty]

:confused:
I will elaborate I guess...:rolleyes:
When the pump is unloaded and pressure drops to some low point, the engines coolant system unloads as well. When the boat re-enters the water the pump "reloads." The time between noload and full pressure or loaded involves a transient time. This transient includes a "spike" in pressure. An accumulator (in this case the air in a canister) absorbs the transient by making the pressure work against compressing air through the time when the spike occurs keeping the spike from being seen down the line which includes the engine's coolant system.
This is a common thing in hydraulics...
Nobody is familiar with an accumulator..? :(
I'm not sure that the average regulator can react fast enough to knock down this problem..?

[Back Forty]

riodog, the :rolleyes: wasn't in regard to you...

[Chris J]

The inverted fire extinguisher should work. Not sure if it will have the capacity you need. Same principal as a surge suppesser used in your house's copper pumping to stop water hammer on your pipes when the solenoid for your washer machine closes. Might want to install a vent valve on top to drain it for winter storage.

[Back Forty]

Thats it!
My idea came from a set up on some borg/warner 73 velvet drives. We used a Co2 canister to get what we wanted there on the high side to keep from breaking things.
Thanks Chris.

[MudPumper]

Originally posted by Back Forty
:confused:
I will elaborate I guess...:rolleyes:
When the pump is unloaded and pressure drops to some low point, the engines coolant system unloads as well. When the boat re-enters the water the pump "reloads." The time between noload and full pressure or loaded involves a transient time. This transient includes a "spike" in pressure. An accumulator (in this case the air in a canister) absorbs the transient by making the pressure work against compressing air through the time when the spike occurs keeping the spike from being seen down the line which includes the engine's coolant system.
This is a common thing in hydraulics...
Nobody is familiar with an accumulator..? :(
I'm not sure that the average regulator can react fast enough to knock down this problem..?
My Hydraulic Concrete pump has an accumulator to keep the hose from surging down line. With out the accumulator it makes pumping damn near impossible. Seems to me like it could work in this case. I would be interested to see a system mounted up in a jet.

[Back Forty]

Thank's mud pumper.

[mickeyfinn]

If you are popping lines it probably comes from a couple of different problems. You are probably seeing a lot of pressure from the pump and when the pump unloads the pressure drops from the pump all the way through the block. I would think that if you are going to run an accumulator you would want to utilize some kind of bladder setup in the fireextinguisher along with an area that will actually contain some amount of water. When you unload the pump the bladder will expand and continue to push water into the block and when you reload the bladder should absord some of the shock and refill the cylinder. We utilize this to reduce water hammer at the plant where I work.

[Back Forty]

The problem starts with a hose that had a localized weak spot. Now that the hose problem has been delt with, I don't want to experience any other variation of the same such as intake gaskets and other stuff.
On the part of trying to keep water to the engine with some sort of bladder and such, I'm not really worried about sending air through the engine. It's going to happen and it's probably the lesser of evils so to speak. Without actually trying to characterize the spike problem, I would venture to guess that the most damaging levels of the "spike" last less than a couple tenths of a second. The use of an appropriate sized canister or accumulator will at least keep my hoses and gaskets in place. I don't think this needs to be a science project really. This is a simple fix. I kind of thought people were already doing this is all.:wink: