Flow unloader

[Dan Stapleton 14]

I want to switch from a pressure actuated to a flow unloader. I usually run my surface cleaner at between 3000-3500. Since the most popular one (k7) is only rated for 3000 I am reluctant to buy one. The zk1 is rated for 3600 but has 1/2" outlet and bypass. Can anyone recommend a good, durable one that has 3/8s plumbing. Seems like the zk1 is built for bigger machines with the 1/2" plumbing and gpm ratings up to 10 plus. I run 4.5gpm and max 3500. Thanks.

[Don Phelps 85]

Why not use reducer bushings to whatever size you want?

[Christopher 102]

Hello Everyone, Not trying to hijack the thread but I was also thinking about the zk1 unloader. I have not replaced one yet but am sure it will happen sometime soon. Other than physically changing it out, what else do you need to do? Adjustments? I would like to know what to do so when I order one I will be able to do this myself. My machine is 5.6gpm, 3000psi hot water. Thanks.

[Dan Stapleton 14]

Why not use reducer bushings to whatever size you want?

I thought of that, Don, I'm trying to find out if the 1/2" flow is needed for proper operation. Seems like it might be with the 10 plus gpm capacity. I dread calling general and jumping through the hoops to get to the right tech. guy. Thats what I'll do if I don't get any info here.

[Don Phelps 85]

The info that I found on it states that it's for 2.4 to 10.8 gpm. It has a 3/8" inlet with a 1/2" discharge and 1/2" bypass. I see no reason why it wouldn't work.

Flow-actuated unloaders can be somewhat fickle when setting up, but after the bugs are worked out they're easier on equipment and the body.

[Dan Stapleton 14]

Thanks, Don. Being fickle and those bugs are what concerned me about reducing. Makes sense though if the inlet is 3/8s. My elbow needs relief from that pressure kick. Keith is working on a new logo for me. Gonna do before/after postcards or flyers, new cards and am gonna hammer the nice developments around here. Hope your staying busy and all is well.

[One Tough Pressure 580]

Use the ZK1 and reducer where needed, it will work just fine. My ZK1 came with a 3/8" inlet & Outlet, while the bypass is 1/2". My last Zk1 had the 1/2" outlet though.

I have run these on 5 gpm and 8 gpm units and they are far superior than the K7.

[Christopher 102]

Is there any adjusting or fine tuning on the ZK1 unloaders? Do you just attach them and they are pre-set for 3000psi? I have not done this before but want to get one and change out my old pressure unloader. Thanks.

[One Tough Pressure 580]

You need to have a pressure gauge and set them to your machine as should be done with all unloaders. Unlike others, they increase pressure by turning the nut out rather than in.

http://www.generalpump.com/PDFs/ZK1-Unloader.pdf#search='general%20zk1'

[Dan Stapleton 14]

Use the ZK1 and reducer where needed, it will work just fine. My ZK1 came with a 3/8" inlet & Outlet, while the bypass is 1/2". My last Zk1 had the 1/2" outlet though.

I have run these on 5 gpm and 8 gpm units and they are far superior than the K7.

Thanks, I appreciate it.

[John Orr 206]

I recently installed a ZK1 on my HydroTek 8 gpm/3000 psi 2-man rig and I LOVE it! A few years ago, I was turned on to the K-7 on my 4000/4 rig and it made a huge difference in ease of use/fatigue. Aside from not getting rocked every time I pull the trigger, not having pressure in the hose is awesome when pulling hose around a building. A relaxed hose is MUCH easier to deal with. As a bonus, if you need to swap guns, it can be done without shutting off the machine.

[Christopher 102]

Thanks for the Link. It makes sense now. I do not have a pressure gauge on my rig. I bought a gauge but do not know where to install it. Where do you put the pressure gauge on the Unloader, before the unloader after the unloader? Thanks.

[One Tough Pressure 580]

I only use my gauges for calibration and then they go back in the tool box. I have one with 1/4" qc's for the gun and another one with 3/8" qc's for before the gun. In order to see the spike pressure, you must have it before the gun.

[John Orr 206]

You can use one with quick connects or use one of the ports on the ZK1, it will screw right in.

[Christopher 102]

Thanks again.