Pressure

[Scott.Downey]

I have a outside bay that has a 5cp2140 pump. Pump is new ,regulator is old. My motor is a 5hp 240v single phase. Pressure is disappointing, pump is running around 1050 psi. I'd like to actually make this a higher pressure bay ,advertise it as such and charge more. I know pressure is variable due to tip size ect. But to truly have 2 handed pressure do i need to get a bigger pump and motor? Or is the 5 cp capable of 1200 or 1300 psi realistically? Bay has roughly 70 ft hose running to it.

 

[MEP001]

A 5CP2140 with a 5 HP motor can do close to 1800 PSI. The pump itself is rated to 2500 PSI. You should be able to get about 1500 PSI with a xx065, or 1700 PSI with a xx06 tip, without exceeding anything. If it won't reach those pressures with those tips, there's something wrong.

 

[Earl Weiss]

Try increasing motor pulley size on pump by 1". That is what I did - same pump.

 

[Greg Pack]

Earl may be onto something. The very common 5CP2120W is a 950 RPM pump. The 5CP2140W is a 1750 RPM pump I think that means the motor and pump pulley should essentially be the same size to get the same RPM as the motor.

https://www.catpumps.com/sites/default/files/products/pdfs/CPSvc%285%29.pdf

Look on page 7 for some helpful information regarding pump RPM, etc.

If the pump is running 1050 psi at the gauge that is probably 800 psi or less at the tip.

 

[Eric H]

Try increasing motor pulley size on pump by 1". That is what I did - same pump.

I remember using a chart from CAT when I was changing for 310 to 530 pumps on my existing 5hp motors. I think the concern here is more about water volume than pressure. You certainly don’t want to starve the pump of water volume but too much volume isn’t good either.
You need to pick your tip size and pressure and select the appropriate pulley sizes.

 

[MEP001]

5CP2140 is most likely direct drive. He's limited to 4 GPM.

 

[Scott.Downey]

Yes the pump is direct drive.

 

[Scott.Downey]

Im going to put on a new regulator and see if i can bump it up.

 

[Randy]

I have a outside bay that has a 5cp2140 pump. Pump is new ,regulator is old. My motor is a 5hp 240v single phase. Pressure is disappointing, pump is running around 1050 psi. I'd like to actually make this a higher pressure bay ,advertise it as such and charge more. I know pressure is variable due to tip size ect. But to truly have 2 handed pressure do i need to get a bigger pump and motor? Or is the 5 cp capable of 1200 or 1300 psi realistically? Bay has roughly 70 ft hose running to it.

Here's what you can do, it's cheap and it'll give your customers the impression that they are getting way more pressure than what they are really getting. Switch over to a 1505 or 1504 nozzle. https://www.kleen-ritecorp.com/p-18...t-connection-1-8-inch-npt-5-gpm-4000-psi.aspx We've been using the 1505 nozzles for over 30 years and get comments about how much pressure we are delivering. When you pull the handle on the gun it'll give you some kick.

 

[Greg Pack]

Scott what size nozzle are you using?

 

[Scott.Downey]

15/05 . I was able to adjust it up. It's showing a little above 1400. I figured it would be vastly different from the 1000 psi that i had but not so much. I can still notice some improvement in wand.

 

[MEP001]

Is it showing 1400 with the trigger pulled?

Does the pressure gauge sit at zero with the pump off?

 

[Scott.Downey]

Yes. 1400 pulled. Sits a zero when off.

 

[MEP001]

You should be able to get a lot more pressure with a 2505 tip. If you try increasing it, watch where it stops coming up on the gauge with the trigger pulled. Once you find that point, back the pressure down where you can see the gauge dip a tiny bit. This will prevent a strong surge of pressure when the trigger is released. People can get hurt by that surge, and it's really hard on the pump to run at a higher pressure without the trigger pulled.

 

[Scott.Downey]

Will do. Thanks for the advice everyone.

 

[Greg Pack]

You might could try a 1506 and see if you can maintain pressure. 1505 is 2.5gpm at 1000psi (at the nozzle) and 1506 is 3 GPM. It will feel more substantial to the customer

I use a 1/8" street tee with a pressure gauge on the end of my guns to get accurate readings.

 

[Roz]

I ran an experiment with four tips, 2505, 06, 07, and 08. The psi drop when the trigger is pulled is 50psi (05), 150 (06), 300 (07) and 450 (08). Basically a log graph. We settled on a 2505 as the kick feels the best and seems to impress our customers.

 

[MEP001]

The reason for the pressure drop is because the pump can't maintain flow with the larger tips. If the pump is running fast enough, the pressure would remain the same regardless of the tip.

 

[Roz]

The reason for the pressure drop is because the pump can't maintain flow with the larger tips. If the pump is running fast enough, the pressure would remain the same regardless of the tip.

I believe we would need a dynamic or variable speed motor for the pump that is programmed to keep the same water psi. Have not seen one with that capability.

 

[864real]

I believe we would need a dynamic or variable speed motor for the pump that is programmed to keep the same water psi. Have not seen one with that capability.

Isn't that what the regulator is for. Set to X PSI and anything above that gets returned to the input of the pump. Then if more volume is needed based on the larger tip size, less would be returned to the pump. As long as the pump and deliver adequate volume at a given pressure it would maintain the pressure. If you put a tip that would require more gpm than your pump can produce at a given pressure, that should be only time you see a pressure drop.