Q&A Forums

Trouble with Equipment Post New Topic | Post Reply

Author Comments
Gustavo Trevino
Posted: Feb 06, 2008 04:47 PM
Trouble with Equipment

We are a new in the business, we just bought a rig from CPI on October, we were working well and we stop for around a month, and we are trying to start again, but we are having trouble with the equipment, I start the machine (e-20)the pumps etc. connect the gun to the hose but when I start spraying it loses pressure on the B side, I already check the gun and purge the hose and It seems that material is flowing, but some how It doesn't throw both materials...

Can anyone help me ???


Michael Flander
Posted: Feb 06, 2008 04:59 PM
Stall test the pumps, if they hold pressure in both the up and down strokes your pumps are okay. From there, you can begin to inspect the machine following these two guidelines:

If the problem is before the pumps on the machine, it will be on the side that is not holding pressure. In your case it sounds like the B side. Supply pump failures usually cause severe spikes in pressure and is generally inconsistent because of pump cavitation.

If the problem is after the pumps on the machine, it will be a restriction on the side that is holding pressure, in your case the A side. What happens is when you pull the trigger your B side flows just like it should and begins to drop pressure, but your A side is restricted so it holds pressure and causes the problem you are having.

Your problem is most likely the latter, start at the gun and work your way back. Mix chambers, the manifold that attaches to the gun, and the block on the machine are all common culprits. Check your screen on both the machine and the gun. Take the manifold off the end of the hose and run the pumps free-flowing, this will give you a good indication of flow between the two sides. And will let you know if anything is causing blockage prior to the gun.

Good luck,
Mike Flander - Endisys
Posted: Feb 06, 2008 08:23 PM
Sounds like you have some crystalized ISO in the lines. Did you not leave pressure in the system when you shut it down?

Tim O'Keefe
Posted: Feb 06, 2008 09:17 PM
George, the Graco machines will not allow you to park the pumps unless the pressure is below 500 psi. If done hot, once the fluid cools, pressure is likely to fall close to 0 at least it does for me. Does the B side come up to pressure on its own without any trouble? I had an issue with the pressure relief valves failing and would allow some material to leak back through the recirculation lines. This caused a loss in pressure as you describe.

Granite State Spray Foam Co.
Gustavo Trevino
Posted: Feb 07, 2008 09:56 AM
Yes Tim I dont have any trouble balancing the pressures, a friend tolme that may be I have some crystalised ISO on the pumps and that I have to clean the lines with DOP, pump at least 5g on each side and put again the pumps on DOP to get them clean, I hope thats the problem
Tim O'Keefe
Posted: Feb 07, 2008 10:11 AM
If it is the pumps, you should not have to worry about the B. Crystalization occurs with the A only unless you contaminated a B drum somehow. What temp are your drums? Sometimes in the cold the pumps can get real lazy and not keep up with the demand of the proportioner. If you recirculate for an hour or so and make sure everything is really hot then see if it still does it.

Granite State Spray Foam Co.
Gustavo Trevino
Posted: Feb 07, 2008 12:33 PM

The temperatures here in Texas are most of the time high, but now that is winter is been cold but never below 30's, the coldes days we were about 35-40 last week, do you think the material is still too cold and the pumps are not working well?? also I know how to resirculate the material, but do we have to buy a set or other equipment to connected to the drumps??? when we bought the rig, it didin't came with any equipment to recirculate the material

Thanks you for your help
Tim O'Keefe
Posted: Feb 07, 2008 01:18 PM
You'll need to by a section of hose (about 10') and remove the little white plastic hoses from the manifold of the machine. One end of the new hose needs to be 1/4" male and will screw into that fitting on the manifold. The other end should be 3/4" male and would screw into the drum. Open your valves and let the material circulate through the e-20 heaters and back into the drum using just the air for the drum pumps (no jog). Once the material warms up it will pump very quickly. The B can become thick in the cold and it is difficult for the pumps to work efficiently. You could easily call for more material than the pumps can supply when spraying with cold material.

Granite State Spray Foam Co.
Posted: Feb 07, 2008 09:58 PM
You can not recirculate hfc245 blown foam. You didn't say if you were spraying open or closed cell.

Gustavo Trevino
Posted: Feb 08, 2008 04:14 PM

I am spraying close cell foam,
Gustavo Trevino
Posted: Feb 11, 2008 07:26 PM
Thank you everybody for your help, already solve the issue, the problem was on the gun, I am using the fusion, I had to change the mixing chamber and some seals and I believe that was the problem...

Thank you for your help!!!

You need to login to reply to this topic. Please click here to login.