green spring or K7 unloader for single gun machine?

[Roy Sanders]

I am told the green spring is for dual gun machines but guys use it for single gun machines as well. It seems like alot of the people I have talked to use the green spring but am told I should use the K7 over the green spring. Thoughts?

 

[HighTide]

I switched from a green spring pressure type unloader to a K-7 flow type unloader years ago. I will never go back. The green spring was tough on my equipment with all the pressure spikes and harder on the operator as well when pulling the trigger plus the surge from the pressure release. However, it's all a matter of personal choice which type unloader one uses.

 

[Sirocco Jerry]

the examplesare absolute "polar opposites" for type, rating, functionality, etc..
the unloader is and has always been the best tool for the pump system for manyreasons..
it is easier on the pump and hoses for minimizing spike pressures, it is saferfor use with a heater system and related controls,
But.. .. is will not work on over 3500psi.. and we all love what 4000psi canpush through hoses over 150ft long.
..I HOUND the manufacturers every time I get an opportunity that the industryneeds a 4500psi version for 5 to 14gpm,
but they won't build anything without a 2000 piece order. :{/

the green spring unloader is known by the heater-coil manufacturers, as the"coil-blaster"
it can allow HUGE pressure-spikes against the pump. heater-coil, and hoses.. especially as it gets worn.
it is pressure-actuated, which also causes mayhem with heater controls, ..alsoblasting heater coils when the heat stays on, with no water flowing.
..and y'all also coincidentally complain about blowing hose reel swivels, andhose-ends. .. ..
..what a coincidence ! Eh?
<o> </o><o></o>
The best of both worlds.. seems to be..
the PulsarZero unloader.. rated 4 to 10gpm, to 4000psi,
and DOES work on multi-wand systems !!
I stock'em at $129.

if all you need is single-user and3500psi max.. the K7 is good to 8gpm, very reliable, and worth rebuilding to a point.. I stock parts.