overfill prevention problems. NEED HELP!
Posted: Wed Apr 18, 2018 2:22 pm
Specifics:
I have a 6k gallon tank, 120" diameter. It is manifold with a 10k gal 120" tank, On-rd diesel. 2" fiberglass manifold line. Single STP in 10k tank. Probe in each tank. Separate Vents.
Issue:
When the truck begins to drop fuel, the overfill prevention valve closes immediately, regardless how much fuel is in the tank. There is also back-pressure on the 4" truck hose as soon as the hose is buttoned to the fill.
Troubleshooting:
- Tried new opw 71so and and Emco a1100 non-coaxial overfill tubes, both did the same thing.
- Cut emco overfill bottom on 45* angle, 8" from bottom of tank
- Blew back on vent line
- removed atg cap to try and release pressure while dropping.
- Removed overfill, installed striaght tube (truck can then drop, but slower)
- Removed overfill, no tube, splash drop (truck can then drop)
Being that the bottom of the tube is normally submerged in fuel at all times, how can there be pressure on the truck hose?
*** It took approx. 3 drops after both tubes were installed for this to start to occur each time. Could this weird back-pressure be damaging the tubes, thus causing them to close as soon as fuel hits them? But, even when the tubes weren't shutting, the drop flow was slower than it should be.
Tube in the tank prior to these didn't work, and was cut too short on the top side.
I have a 6k gallon tank, 120" diameter. It is manifold with a 10k gal 120" tank, On-rd diesel. 2" fiberglass manifold line. Single STP in 10k tank. Probe in each tank. Separate Vents.
Issue:
When the truck begins to drop fuel, the overfill prevention valve closes immediately, regardless how much fuel is in the tank. There is also back-pressure on the 4" truck hose as soon as the hose is buttoned to the fill.
Troubleshooting:
- Tried new opw 71so and and Emco a1100 non-coaxial overfill tubes, both did the same thing.
- Cut emco overfill bottom on 45* angle, 8" from bottom of tank
- Blew back on vent line
- removed atg cap to try and release pressure while dropping.
- Removed overfill, installed striaght tube (truck can then drop, but slower)
- Removed overfill, no tube, splash drop (truck can then drop)
Being that the bottom of the tube is normally submerged in fuel at all times, how can there be pressure on the truck hose?
*** It took approx. 3 drops after both tubes were installed for this to start to occur each time. Could this weird back-pressure be damaging the tubes, thus causing them to close as soon as fuel hits them? But, even when the tubes weren't shutting, the drop flow was slower than it should be.
Tube in the tank prior to these didn't work, and was cut too short on the top side.