Wayne G.

Searched the forums and cant find any posts on this. When I wash flat surfaces I am at 8gpm and 3500 psi with cold water when using 100 ft. of 3/8" ID 4000psi typical high pressure hose. I want to go to 100 ft. of 1/2" ID hose to reduce pressure/flow loss. 1/2" ID 4000 psi sewer jetting hose is cheaper and lighter than the corresponding typical high pressure hose.... Any recommendations?

Thx. for the info guys. I am losing about 500 psi with 100' of 3/8" and according to the Gates Hose Online fluid flow calculator that is about right.

On occasions when I am running 8 or 9 gpm and 3500psi with spikes higher than that when the gun is closed. I am having a big problem finding a two way 3/8” carbon steel ball valve that can handle that. I have some 6000 PSI Alco PB3NS-LS which are OK but they are $100/ea and I have to order two at a time.I use Parker valves for my lower pressure apps with good success. However, their valve with these specs is no good. Does anybody know of anyone else who makes a good 5000-6000 psi valve?

Need feedback on the brand itself and specifically the RKV5G40 direct drive (5gpm @ 4000psi)

I have an 8gpm/3000psi setup with a Steel Eagle surface cleaner for cleaning flat surfaces. Have tried many different ball valves and the best one I have found (Parker v-500hp-6) rated for 6000psi does not leak, but becomes very hard to turn after a few jobs. I do not ever "throttle" this valve... it is either wide open or closed. Anybody have suggestions on a better ball valve for this application.

Any ideas on how to remove this black stain on stucco/dryvit from asphalt shingles when you can not get up close to it with a wand?

Thanks guys - I do not use a specialty chemical to clean gutters. Any recommendations? I have heard that Simple Green works but in some cases has done damage... is this the case?

I have a 4000psi pump with a pressure sensitive unloader. If I adjust the unloader to where the pump puts out the max psi that the engine can produce, which is about 3700psi, when the gun is closed and it goes into bypass then my pressure spikes to 4300 to 4500psi. Will this practice significantly reduce the life of the pump? I have heard that the pressure in the system with the gun closed in bypass mode is kept in the high pressure hose between the unloader and the trigger gun, so the pump would not be subject to the pressure spike. Is this true?

MMI - Have not seen check valves for sale by themselves at Delco. I bought some additional check valves at the local Parker Store (Parker-Hannafin Corp)

MMI - The co is Delco Cleaning Systems. There website is dcs1.com. Download their Wats Blaster Catalog and the Power Booster is on page 21 in the top right hand corner.

MMI - I bought something called a Power Booster from a pw distributor. It combines the water flow from both my cold water portables. Works great! If you think this would help you and it is not against site rules to post info on distributors and there catalog items then I will be glad to give info on it.

Beth - Thanks for your input. I use 3% bleach and laundry detergent downstreamed at about 8 to 1 to clean houses. And I'm pretty sure this will not help. Any house wash detergent suggestions?

MMI - I have noticed a difference in cleaning at 3600psi vs.3300psi and thought the step from 3700 psi to 4000psi might result in the same difference.

I have looked for a vertical pump with a flange to bolt up to a 15hp gas engine with a 1" crank and can not find it. I know this is an oddball setup, but I have this engine left over from a lawn care business and would like to add the pump and sell it. Also, need info on a cart for this setup.

Thanks MMI!

MMI - thanks for the info. I am currently cleaning a 36,000 sq ft parking lot so a turbo is unrealistic. And 95% of my work is residential, so I can not justify nor do I have the money for a hot water unit. My setup is two cold water units plumbed together so I have 9 gpm and 3600psi at the pumps

Ken I am cleaning very dirty aggregate with cold water and no chems.

Russ - If I want 4000psi at the nozzle. Then what I need is a 4500 psi pump with the appropriate engine to drive it to that capacity and correct nozzle and set the unloader where it runs at 4000psi with the gun open and spikes to about 4500psi with the gun closed...Correct?

Thanks Russ!

Ken, thank you for your response. I am confused. My pump is 4gpm at 4000psi. I have a 13hp gas engine that will drive the pump with a 4.0 nozzle and 50' ft of hose to a max psi of 3700. But with the unloader adjusted like this, when the gun is in the closed postion the pressure spikes at the pump to 4300-4500psi. Should I adjust the unloader to where the max psi at the nozzle is about 3500psi so when in bypass the spike is around 4000psi at the pump instead of 4500psi?