Flow unloader or Pressure Unloader?

Which is better on Steel coils?

  • Flow Sensitive Unloader.

    Votes: 16 57.1%

  • Pressure Sensitive Unloader.

    Votes: 8 28.6%

  • 3000 psi to 0 and back again.

    Votes: 1 3.6%

  • 3000 to 3500 psi and back again.

    Votes: 3 10.7%
  • Total voters
    28
Hotwaterwizard

Hotwaterwizard

Hotsy Service Tech
There is a battle going on between the experts on which unloader is better. Flow sensitive or Pressure sensitive.
Which one is better to the guys that use the machines?

1) Flow sensitive.
When you pull the trigger on the gun, the pressure increases slowly as the flow increases. There is a short delay each time you pull the trigger. This unloader relieves all of the pressure from the gun and hose each time the trigger is released.

2) Pressure sensitive.
Sometimes called lock-up unloader. When you pull the trigger you get a sudden burst of pressure at the beginning then it levels off to a steady pressure. When you let go of the trigger the pressure will climb up to the set pressure and stay there in your hose untill you pull the trigger again.

Here is the debate if any one would like to join the experts.
Is it better for heating coils made of metal to expand to the set pressure of an unloader then back down to zero or, is it better to go from the set level up to the set level.
in easy terms here is another way to say it.
If your machine puts out say 3000 psi.
Is it better on the metal to go from 0 to 3000 psi then 3000 psi back to 0 (Flow Unloader) or, is it better to go from 3000 psi up to 3500 psi and back down to 3000 psi again. (Pressure Unloader)


__________________
Hotwaterwizard@aol.com If You have a problem with your machine, just ask I'll help if I can.
 
Yeah I’ve heard the argument, I change a few years back to a locking unloaded. Facts are that I have replaced unloaded way less and have seen no real extra wear on the equipment.

I feel they like the pressure sensitive because they can keep selling you them. just my opinion
 
Just Trying To Ruffel Some Feathers With This One!
 
Does anyone know the difference between a Flow unloader and a Pressure unloader? Check out the results of this poll. Most chose the Flow unloader then marked the Pressure differential for the Pressure unloader.
 
Hi,

While we are on the subject of unloaders, I believe mine is pressure sensetive. I'm wondering what can be done to change this so that when the machine is running and the trigger is not pulled on the gun, the wear and tear can be reduced on the machine. As we're all aware, homeowners/customers love to talk, especially while our machines are running and we're working.

Thanks,

Chris Anderson
 
Chris Anderson said:
Hi,

While we are on the subject of unloaders, I believe mine is pressure sensetive. I'm wondering what can be done to change this so that when the machine is running and the trigger is not pulled on the gun, the wear and tear can be reduced on the machine. As we're all aware, homeowners/customers love to talk, especially while our machines are running and we're working.

Thanks,

Chris Anderson
Click to expand...

I qouted the wrong quote before:eek: :confused: ... This is the right one :D
 
Chris Anderson said:
Hi,

While we are on the subject of unloaders, I believe mine is pressure sensetive. I'm wondering what can be done to change this so that when the machine is running and the trigger is not pulled on the gun, the wear and tear can be reduced on the machine. As we're all aware, homeowners/customers love to talk, especially while our machines are running and we're working.

Thanks,

Chris Anderson
Click to expand...

I remember voting in this poll when it was first posted over 6 years ago! Interestingly, I recall thinking back then that flow unloaders (eg: K-7) were the way to go, and wished I could get one on my machine.

All unloaders bypass excess pressure when the trigger is released. A pressure unloader maintains your set pressure and a flow unloader releases (almost) all pressure. The issue when in bypass is the heat build-up in the water being bypassed - the less water, the faster it will over heat. As I recall, you need a float tank on any machine will allow you to "chat" longer.

I have been running either a K-7 or K-1 since I attended a Steve Rowlette Roundtable in Raleigh, NC about 5 years ago. Until you experience the difference, its hard to imagine.
 
I had a pressure Sen.. Unloader on my whitco for years and every time I hit the gun it was like murder on the pump, you could actually watch the pump and motor rock on its base.. My new unloader is flow sensitive and just the feel of it makes me feel like my pump will last alot longer. I have it adjusted to 2800 psi on my ts1511 pump.. It works really well.. also I notice since the pressure doesnt just pop up right away ... It takes a second or 2 to get to 2800 , the motor does not bog down as hard as it used to...
 
This problem and slow kick in can be helped ny removing the bypass piston spring (# 12) and stretching it a little. Make sure it gets stretched evenly, you don't want to make it crooked.

K7.jpg
 
How much should the spring be stretched with regards to the below???


This problem and slow kick in can be helped ny removing the bypass piston spring (# 12) and stretching it a little. Make sure it gets stretched evenly, you don't want to make it crooked.
 
I will answer 2 questions from my experience. I use a K7 unloader on everything we have, except the small electric unit.

I have only had the system dump into bypass if there is a bad leak. (O-ring blow out between hoses ) Ive run up to 600' with no problem.

Sometime on a long run of hose there is a delay from when you pull the trigger and when you get pressure.

What I do to speed up the delay is: remove the tip, pull the trigger for about 2 seconds ( this gives you flow ), replace the tip and then pull the trigger again. This seems to jump start the K7 unloader when you have a long run of hose. If the problem continues the system probably need descaling. The unloader gets hardwater lime buildup and gets sticky. If that doesnt fix it replace the unloader.
 
The other good thing about flow unloaders is they will not let you use the wrong tip. If the tip is to small it will not operate. On the other hand you can not use 2 guns with a flow unloader because of this problem. You must use a Trapped Pressure unloader for 2 gun machines,
 
sparkie1 said:
How much should the spring be stretched with regards to the below???


This problem and slow kick in can be helped ny removing the bypass piston spring (# 12) and stretching it a little. Make sure it gets stretched evenly, you don't want to make it crooked.
Click to expand...

1/8" - 1/4".
 
Lets try to submit this to General Pump for an upgrade
 
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