Beckett has a Technical Information Bulletin "Solving Nozzle Afterdrip". They say there are 3 causes.

1- bad pump.
2-air trapped in the nozzle adapter.
3-excessive heat,radiated heat directed back at the end cone

 

wish I had a like button...

 

LOLALOT!

 

I found that bulletin already.

1) I tested the pump and its good by going by their directions.

2) It wasn't spraying when the burner stopped when I tested it. I'll check this one again.

3) The boiler liner is in good shape and only the front of the gun is in the fire chamer.



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#3??The burner end cone protrudes into the fire chamber area,being past the liner?

 

Does it keep dripping and doesn't stop or does it drip a little but stops?

 

I'm not exactly familiar with beckett nozzles but I know I had this problem on a sectional boiler, 150 psi and every time I went it had a large puddle under the gun where it bolts to the boiler. I could watch the nozzle drip rapidly for about 15 seconds when it shutdown. I called powerflame support and they mentioned that what I had done changing the nozzle and screens and pump was good but if it was leaking down still it may be the return line check valve, the tank in my case was outside and of course well above the burner level, that solved the drip, there were dual checks in the powerflame setup and also after any repair the tiniest little air bubble would cause a drip so bleeding it was paramount to stopping the drip. maybe Beckett has a return check?

 

No checks allowed on any return line by code. If

 

these were checks off the pressure control on the outlet of the pump back into the return line from the nozzle relief, not in the main return line, sorry for the confusion.

 

I checked the end cone is past the door liner less than 1/4in. I replaced the pump because the one there was original to the burner. I also checked to see if I had any bubbles in the oil .When I bleed the pump the oil wasn't foamy. The after drip is still there and im stumped.

 

I was able to really reduce the drip on one by re leveling the burner, it was tipped just slightly towards the boiler, I ran it dead level and it helped, just an idea and I’m not sure It should really matter but it helped in my case, I believe the instructions call for level.


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Where does it say that it OK to have the end cone within the combustion chamber/area? Just curious.

 

Usually never, but some newer boilers, especially with Riello's in them are actually protruding into the combustion chamber, some a few inches.

 

You could’ve damaged the nozzle line surface where it mates with the nozzle if it was over tightened.

Following up on what @ TechmanTerry said:
It could also be excessive heat left in the chamber, combined with the insertion depth issue.
You can check for excessive heat with a k type thermocouple, the kind you use with an electric meter (wire with a little bead on the end).
Slip it into the air tube near the nozzle, attach to meter. Run the burner for a cycle (10-15 min), shut it down, see what the temperature is, and does it climb.

Another option, is to add on an oil valve, non delay, between the pump outlet and the nozzle line.
Also proper bleeding of a fuel pump requires you use a tube attached to the bleeder and the other end submerged in oil in the container you are bleeding into. And then there is a power vacuum bleed.

 

:cheers:

 

How do you know you have afterdrip versus impingement? Also, oil burners are supposed to be slightly down hill.

 

How do you know you have afterdrip versus impingement?

I guess we'll never know without draft, smoke, and a full combustion test.

 

Every time you change the nozzle or filter you put air in the system. This can take up to a week or more to purge, unless you know how to outgas the filter. Also, 2-line systems are famous for cavitation and air separation which contributes to afterdrip.

Delayed afterdrip (heat migrating back into the air tube) is caused by negative pressure problems and can be determined by a draft test.

 

Amen! :cheers:

 

Sorry I haven't replyed, its been a busy week. This burner is having an after drip. I checked the operation with a mirror when its running and shuts down. Ill have to get a borrow a kit and run a combustion test.

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You can google "power vacuum bleed". I do it every time. George Lanthier has written a few articles on it, and mentions it in a book he wrote about fuel pumps.

 

So I found some of George lanthier’s articles on the subject on fuel oil news website. Great great stuff, thank u. Had a oil leak callback on a guy and then a triple prime and start after a run out this afternoon. Outgassing the filter worked perfectly on each unit i touched today. Big difference to the way I was taught to bleed the fuel pump.

Now I’m trying to get the materials together to build the “AcCoolant tank bleeding container” that Lanthier mentioned in the one article. Looks like it would make things even easier


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What MN# is this Slant Fin boiler??? I have to see if the protruding end cone is allowed by the Mfrg.

 

On Sunstrand pumps information it said to reset the internal check valve. With the burner off, to turn the pressure adjustment screw all the way in and then back out, turn on the burner and adjust the pressure. I had found most drips are because the internal check valve or a failed check valve. I reset the check valve routinely of PM's.
I can't say if this procedure applies to all brands of pumps.
I have not found filters outgassing to be any problem. That's not saying it isn't, just it had not been a problem for me.

Sid Harvey ( are they still around?) sold a check valve that went in the oil line to the nozzle for this problem.

 

:cheers:

 

I worked with a HVAC wholesaler for 15 years that rebuilt Sunstrand and Webster oil pumps. We had a test bench so I could play with different things. We sprayed into a clear glass container so we could see after drip. Tried oil valves, check valves, No-Airs and nothing prevented after drip except getting rid of the air.

When combustion testing and watching CO at Shut-down it can be determined if there is after-drip or impingement,

 

:cheers:

 

Yeah tools are done unless you take one of his classes. Books will be back in the Spring. When we last spoke via email he said he’s officially a snowbird, out of Massachusetts for the winter.

 

CO, CO2 It's all the same thing man.. I did think you meant CO2.
I know some burners just light better. The old shell heads with really long burner tubes ( some 3' long) always lit off better and shorter tubes seemed to have more ignition problems. Long tubes had a slight delay before full combustion air arrived over short tubes. The worse, GE Upshot.
Probably in most cases the combustion process wasn't analyzed as close as might be today. I remember a guy that said he always replaced a nozzle with the next larger so he would get better ignition. After a few years of going to the same burner the nozzle was way more than one size larger.

 

As I learned over 30 years ago, if you don't measure CO on oil you are asking for trouble. CO2 and smoke readings do not tell the whole story. Seems like forever techs have said that oil is dirty and stinky. Okay it might have a smell, but we are the ones that make it dirty.

Is there that much oil in New Mexico or are you a transplant??

 

Check cut off. SOULD BE NO MORE THE 20%.