Sprayer Problems

[Dale30]

I've got a new to me Ace centrifugal pump that I bought to replace the roller pump I had on my sprayer. Im having trouble getting it to make any pressure. I always sprayed at 40psi with my roller pump and when it was new I had no problem getting 80psi out of it. The Ace pump struggles to get 45psi at 540 rpm blocked off at the booms and agitator, kick on the nozzles and it'll drop to 30. I always ran about 450rpm on the pto with the roller pump so as not to run the tractor to hard but I couldn't begin to do that with this pump. I don't know what the problem could be other than the hose size on the sprayer maybe? Ive got 3/4 going into the pump and 1/2 to the booms and agitator, the pump has 1 1/4 inlet and 1" outlet so maybe its not pushing enough water to make the pressure I don't know? The sprayer has an electric controller but it checks out and works good. It also has a bypass line coming out of the pressure reg. back to the tank but you can block it off and it makes no diff. either. Any help on this matter would be greatly appreciated cause it wont be long till time to spray!

 

[RM-MN]

For any pump to make pressure it need liquid...and you are starving your pump with too small of lines. Maybe you have a smaller boom sprayer than me but I have a 2" inlet and a 1" outlet to push a 50' boom.

 

[Bob Bancroft]

That sure doesn't sound right. I'm pretty sure my old Century sprayer had a 1.25" suction line, and a 1" pressure line to the valve. I think the lines going to the booms were 5/8". The centrifugal won't make pressure like the roller, but it has tremendous volume. Enough so it should be easy to make 40PSI.
Does your Ace have the big pulley, for 540 PTO? Have you had the pump apart and looked at the impeller? No restriction coming out of the tank?

I don't think you're having this problem - otherwise you would keep losing prime. The discharge on the pump needs to be at or near the top.

 

[Dale30]

Ive got a century sprayer also, it has a 30 foot boom on it. I took the pump apart today and cleaned it, the impeller looked good so I don't think its really a pump problem. Im almost convinced that I'll have to increase my inlet and outlet hose sizes to cure the problem but just wanted to get some thoughts on it and see if anybody had ran into this prob before.

 

[Lazy WP]

You say its new to you. Is the pump worn out already. The impellers and valute both will wear out over time and not give you pressure. Is the pump the correct size? Lots of variables involved.

 

[TractormanNC]

Hey Dale

As RM says, you are starving your pump. You need lines at least as big as the pump ports, especially the suction on a centrifugal pump. The pump should be located BELOW the tank so it will prime. An Ace PTO pump is NOT self priming. As far as being easy on the tractor by running at less than 540 RPM on the PTO forget it. Pull the throttle down and let her scream. A centrifugal pump must be screaming to do its job. 10% over 540 on the PTO will not hurt the tractor or the pump.

 

[Mike Aylward]

Roller pumps and centrifugal pumps are plumbed differently. On a roller pump the pressure is regulated on the output side. On a centrifugal the pressure is regulated on the bypass or agitator side. If you are trying to raise pressure on the pressure side of a centrifugal pump all you are doing is reducing flow to the boom and raising it to the bypass. Mike

 

[Dale30]

Today I put hoses on the sprayer same size as inlet and outlet on the pump. It will pump 50psi no problem now so Im sure that it just wasn't getting enough water to work right. Thanks for your help.

 

[midtnman]

Somewhat related to this project... strainer on a cent. pump goes on discharge side,roller pump on the suction.Don't
want to clog up and starve a cent. and burn out the two piece seal.