Pump vacuum on Beckett AFG burner?

Mark R.

I have an AFG burner with a Garber filter and a vacuum gauge on the suction side of the filter. I have a two line system. Oil tank is above ground, boiler in basement, and about 45 feet of oil line. A couple weeks ago in mild weather there was 0 in. vacuum with burner running. Then the weather got colder down to 14*. I checked the burner a couple days ago and it was showing 3in. vacuum. I have not had an oil delivery to stir up sediment. This did happen last year after a delivery. Could the temperature cause the oil to thicken enough to raise the vacuum? Or is it more likely that water/ sediment is clogging the filter? How much vacuum can the pump deal with? I am considering changing over to a single line system, since I watch the oil level, and don't worry about letting the oil level get too low. I thought reducing the oil volume through the filter might help if it is sediment/water. I would appreciate any help, and ideas. Thank you, Msrk R.

todd s

oil lines

Get rid of the return line. If this is truly running at 0" then the two pipe setup is going to cause higher vac readings. I never hookup any burners on two pipe, unless the return line is going to a tigerloop. The only thing a two pipe system is good for is the guy selling you copper, he'll always sell twice as much.

Weezbo

this could best be described as the right things

in the wrong places..a simple tiger loop after the osv a ?bag off the return oil line to the tank. you are creating the very problems you wish to avoid.

soot_seeker_2

what would happen?


just a thought (cause i'm thinking of doing the same).

what if, instead of just capping off the return line, you run both the feed & return together into a flare tee & then run that single line into the filter & then the tiger-loop? in other words, as long as you're not going to use the return as a return, then why not use it to effectively double the width of your feed so that the flow works better (lower vacuum)- especially during the colder months when the oil is thicker???

ss

Weezbo

well,

heres a thing to think about for a second, if the supplies and returns piping was thesame length,and the restriction in flow happened to be equal through the t and it was in deed installed correctly,....wouldnt you effectively run out of fuel faster ? )) what you mean ? ) the return is usuall installed higher in the tank than the supply so it is really possible that you would just be making a new problem for all your hard work. while there is something to be said for having a return in oil i have also seen them 20" above the deck of the tank...wouldnt that be fun ?, call the fueloil company Martha Itsa winter again! we need to have another truck on standby sent out ...nah
if you had the thing piped in with one inch black iron there is a satisfactory way to add a supply and return off of it however youd likely have a pump pushing the oil to the burner with a osv and things would be different.

soot_seeker_2

i did think about that..


i did think about that. but i guess it's tough to know exactly where the return comes back in. my tank is a 550gal inground oval - i'm not sure if it's original (1964) or replaced at some point but most of the drawings that i've seen of this style showed the return within 4" of the feed. if that's really my configuration & if the oil supplier doesn't let me fall below 100 gallons, then i may be ok, if not, then i guess it's 'hey martha' time .... they'll probably think my K factor went screwy.

ss

Rookie_3

Mark

I believe the numbers are 10" max of vacuum on a single stage pump and 15" max. on a two stage and then cavitation can become a problem. Vac. is calculated at 1" for every 10'of horizontal run and 1" for every 1' of vertical lift. Elbows and filter will add a few inches also. I would think that 14*F #2 oil would need a little more pull than it would at 40*F. Are you actually having a problem with the 3"hg ? I may be wrong but I don't think 3"hg on a filter vac. guage is a major restriction.........ROOKIE

Weezbo

*~/:)

i havedone so much work that i was bound to have made at least one or two mistakes along the way...:) trust me ...one line is sufficent. the tiger loop though thats a definite pluss in the right direction.

Mark R.

Weezbo, I hate to admit this, but I don't know whatan dosv is. Abnd also what did you mean by a ?bag. I appreciate your help. Mark R.

Mark R.

Weezbo, I hate to admit this, but I don't know what an osv is. And also what did you mean by a ?bag. I appreciate your help. Mark R.

Mark R.

A little more info. After I submitted my thread above, I checked the vacuum this evening after a 56* day and the vacuum had dropped to 1". Obviously the temperature change was a big factor. I guess that gives me a baseline for how it changes with temperature. Pretty soon you guys are going to get me educated. I really appreciate all your help.
Mark R.

Weezbo

i no type well, i was breaking bricks in karate class the year i took typing ...and i not good at it now either. .....bag off the return line is Acient Modern hippi terminology for lose it. an oil safety valve is a fancy lookin POS that main tains like 4psi of oil right where you put it..it isnt a check valve exactly,.. its a little more like a pressure regulating valve with a diaphram in it.. oil lines that are pressurized by a pump pulled of a 2" black iron distribution main in a building or a burner under a day tank, or a burner under ground in a basement with a gravity pressure on the line should have one as it helps keep the oil pump seals from taking an early retirement.....