Piping Experts: 485' pipe run problems

[fingur4]

Happy Wednesday!
We have a 485' underground double wall pipe running through a 3" drilled chase from our bulk plant (AST) to a UST. TL550evo runs the whole system, monitors UST level, turns on off pump based on certain conditions. The control works fine, 3+ years now. Pump is 4" 2hp RJ pushing through LC M5 meter then to transition sump to interface with double wall underground pipeline.

Problem we have faced in winter is that flow slows and slows down to about 10gpm, the colder the slower. Pushing diesel, and I understand the viscosity issues with cold weather, however fuel is treated and has always looked fine on inspection (clear and bright). AST's, STP and related piping are all outdoors.

STP is mounted horizontal (not my design) in basically a 4" riser about 4' long. this is bushed down to 2" pipe feeding it from a shut off solonoid and then to 3" manifold (4 AST's feed system). A Franklin packer head (gutted, no line leak or anything) discharges to the meter, then transition sump, etc.

Anyone have any experiance running an STP horizontal and not in a flooded tank? I would presume that many STP's spend some time in their life only partially submerged in product as station owners tend to not overly pack tanks of marginal product (PUNL, etc) so I dont think that would be a problem, but I would appreciate insight. Any insight, actually - I have been scratching my head for a couple years on this. Verified no apprant restrictions in above ground, solonoid opening fully, no inlet strainer on meter, meter spins completely free, etc.

Look forward to whatever you guys might think!

Thanks,

D

[ATLTech]

STP is installed horizontal? Pics?

[dieselengine9]

What is your normal flow compared to the slower flow in cold weather?

[romfolmar]

I too would like to see pictures

[rmurray]

I would presume that many STP's spend some time in their life only partially submerged in product as station owners tend to not overly pack tanks of marginal product (PUNL, etc) so I dont think that would be a problem, but I would appreciate insight.

The inlet of the motor is supposed to sit about 6" from the bottom of the tank. The product level should never get that low, because the motor needs the product flowing through it to cool it. I've been on a lot of calls where they run the tank dry and it doesn't work again after getting a delivery. A lot of burnt up motors.

I'm also curious how this thing is set up, I've never heard of a horizontal STP.

[fingur4]

https://flic.kr/p/2iyEEgT

[fingur4]

STP is in horizontal 4" pipe. Immedietly to left pipe is bushed to 2", which feed its 4" and STP. I will take a better photo next time. maybe.

[romfolmar]

Why would anyone design it like that? It was never intended to function like that.

[fingur4]

I agree, however at the time the company doing the work has the owners ear. Since then we have made some adjustments to our relationship .
Question is, does it affect performance? I'm sure long term isn't good, as the bearings and such aren't designed for this orientation.
In operation, due to how fuel is pumped into bulk plant an air pocket forms 'above' the motor (between the motor attaching flange and the packer head). Doesn't seem to hurt anything, however the 4" pipe immediately adjacent to where the pump is operating has become quite warm a free times. Never had a failure though.
I agree it's dumb, but can't think of a better way without causing other problems, short of stuffing the stp in a 27' tall AST, which would kill GPM itself I think.
Just curious if anyone has any ideas on performance based on this configuration, or ideas and/or suggestions why the flow is so crappy (12gpm at worst, 37 at best). Interesting note (I thought): line pressure at pump outlet never more than 35psi with 2hp STP, no pressure stat or any other sensors or controls.
Thanks for the reply

[romfolmar]

Check valve in sub pump head could bind maybe. Not needed to hold fuel in piping,could be removed from system