let's talk about set-up's

[Aplus 525]

BE

Two are flow, and two are pressure. I have read somewhere that flow unloaders wear out and fail more often than pressure activated unloaders. The washers that I use for decks are both pressure activated because I'm standing on the ground.

The machines for everything else are flow, because sometimes I'm not standing on the most ideal surfaces, and I don't want sudden kicks to cause me to lose balance.

[Paul B. 523]

EnviroSpec has a very nice write-up about the two types of Unloaders (Pressure & Flow type) and their advantages and disadvantages (It's in their catalog - I have not checked for the same info on-line). I think this will explain why a Pressure type unloader would benefit from an Accummulator.

In a nutshell, the Pressure type unloader has a check-valve that keeps the water between the gun and the unloader under pressure. The Flow type unloader relieves most of this pressure in the bypass mode. They also state that the Flow type unloader (K-7 & K-5) do not allow the operator to down-size the high pressure nozzles because it senses flow - reducing flow at the nozzle causes the unloader to cycle repeatedly (this would also account for a possible shorter life of the Flow type unloader).

Also the Flow type unloaders should not be used with a weep gun, as leaks will cause it to cycle.

I believe a bladder/dampener installed between the the Actuator type unloader check-valve and nozzle will reduce the shock load sensed by the operator. The check-valve should protect the pump (depending on its restriction of back-flow).

Hose length will effect pressure - longer the hose the less pressure at the nozzle (mostly due to friction while water is running). However, in my opinion, depending on how quickly the unloader goes into actual by-pass mode will determine how much pressure will be in the hose between the check-valve and the gun-valve in the by-pass mode. (I'm not familiar with the components of a weep type gun, but assume that it's a valve that weeps off pressure in the valve closed mode. I know it's key advertised feature is for use in cold weather situations to keep water flowing to protect the gun from freeze-up.)

Bottom Line (my opinion):

The safety concern would be mostly to the operator from the built up pressure in the hose (especially if the operator is on a ladder).

Remember: "Safety First and Make It Last!"

[ron p 500]

you are incorrect about EPP'S. Micheal is the reason i even started this subject. His knowalge earns him respect and his post's on needing a dampner on runs over 150 ft. is the only reason i even knew anything about them.

His post was on delco's oldest bbs.

[beyoungsr 14]

Ron,

There is a reply to this subject on Daves board by Michael Stillwell from EPPS and also Scott Stone.