Scratching my head on a new Sprayer/Roller pump

[jenkinsph]

I would use a "full port" ball valve for a suction line, this type does not reduce the bore of the valve. When shopping for ball valves you will find that some are marked 400 wog and have restricted ball valve bodies, these normally are a little cheaper. Others are marked 600 wog and are not restricted through the ball valve bodies and are the full port valves.

A couple of good clear pictures would help us help you.

 

[SPYDERLK]

I think you guys are on the right track with insufficient flow on the intake line. I spoke with folks from both the pump and sprayer manufacturers, and have decided it must be insufficient flow for some reason. What's puzzling is that this is a combo they have been selling for years, with no problems.

I have double and triple checked everything. I had a little bit of extra slack causing an "S" turn in the intake hose, so I cut it off to try to straighten that hose out a bit. After looking at the system, it seemed like the tightest constriction from the tank to the pump is when it goes through the ball valve in the cutoff. It is a 3/4" line, but the ID of the ball valve is probably 3/8". Fimco sent me a new valve with a larger ID on the ball, and I am going to replace with that one and see if it works better.

This is it! When you restrict a suction circuit you start getting cavitation from the combined vacuum and turbulence. ... Thats the handful of bolts noise. Very harmful in the long run.
,,,larry

 

[Thomabear]

This is it! When you restrict a suction circuit you start getting cavitation from the combined vacuum and turbulence. ... Thats the handful of bolts noise. Very harmful in the long run. ,,,larry

X2
The 3/8" ID line will provide only 25% of the flow of a 3/4" line which is starving the pump.
.375x.375=.140625
.75x.75=.5625
.5625/.140625=.25 or 25%

 

[SPYDERLK]

Pi are square. ,,

 

[Thomabear]

Pi are square. ,,

Yep, that's the one to use to get exact area... To get % increase or decrease in flow area either calculation will yield 25%.
Or you can use the basic rule that doubling ID will equal 4x the flow area... All 3 ways are a different way to skin a cat with the exact result of 25% flow through the 3/8 ID valve verses a 3/4 FO valve.