Pump turning backwards

[Maplewalnut]

Guys-

One thing I don't have set up right is my check valve to prevent from my sp-22 pump wheel from turing backwards when turned off. My current piping is...I come off my pump cannister to a regulator and then to a check valve before going to releaser in the bush. If I turn off the pump and depress the regulator at the same time the pump wheel does not turn and vacuum is exhausted. If I dont depress the regulator and just turn off the power it spins backwards until the vacuum is released. I already tried to turn check valve around thinking I had it backwards but of course then I got no vacuum past it. Thoughts

[ennismaple]

Put your foot on the pulley when you turn the pump off. That's all we do when we turn off our SP-22's. Once you stop the momentum the residual vacuum isn't strong enough to re-start the backwards movement.

[red maples]

I have a ball valve right next to the vac. I shut that valve hold the regulator open. I only holf it open if it starts to backwards.

[Maplewalnut]

Yea, but shouldn't the check valve prevent it from turning backwards without any manipulations? Maybe the check valve should goe before the regulator?

[Haynes Forest Products]

Im with Maplewalnut on the placement.......Now why dont you want the vacumm out in the lines at shut dowm time. Doesnt it make more sense to let the vacuum level drop slowly as sap fills the line and heads to the tank or releaser. I would think opening the vac reg would cause a sudden back surge of dirty sap into the tap holes:mad:

[Russell Lampron]

Guys-

One thing I don't have set up right is my check valve to prevent from my sp-22 pump wheel from turing backwards when turned off. My current piping is...I come off my pump cannister to a regulator and then to a check valve before going to releaser in the bush. If I turn off the pump and depress the regulator at the same time the pump wheel does not turn and vacuum is exhausted. If I dont depress the regulator and just turn off the power it spins backwards until the vacuum is released. I already tried to turn check valve around thinking I had it backwards but of course then I got no vacuum past it. Thoughts


The check valve is probably doing what it is supposed to but the tank still has vacuum in it. You need to move the check valve so that it is between the pump and the tank. The pump won't turn backwards and the vacuum in the tubing will gradually drop.

[Dennis H.]

I think the checkvalve should be on the exhaust of the sp.
It would prevent the sucking of air back thru the pump thus turning backward.

But the ballvalve right near by that can be opened when you turn it off would be cheaper.

Haynes I agree that keeping vac on the system would be the best thing but even the perfectly tight system would slowly loose vac after a few minutes. The tress are just to porious.

[brookledge]

My vac. pumps have a rubber flapper on the end of the exaust and when it is shut off it sucks back tight to prevent the pump from running backwards
Keith

[Russell Lampron]

The oil fill is right under the muffler on an SP22. Putting a check valve there would keep the oil that collects in the muffler from draining back into the crankcase when the pump is shut off.

[Dennis H.]

It just needs to be somewhere on the exhaust side. It can even be way at the very end.

[red maples]

I have a bb2 but its very close to the sp11 and sp22 just the earlier model as you all know.

but anyway thats why I have a ball valve to shut it down first so I keep the vac in the line!!! It works for me!!!! but your right you don't want any back flow inthe line!!!

my system goes

Vac. (NO tank it runs directly into the vac. which is why I get condensation in the oil but I point the exhaust pipe down with out a muffler no problem, I'll make one some day but its on the end of the list)

Vac---Relief valve----ball valve----Pressure gauge----moisture trap-----check valve----then out into the releaser.

The whole thing is about 3.5 feet or so. That's the way I was told to set it up. with relief valve closest to vac then ball valve to close off line and make it air tight. and the rest you know.