using washers in oil line coupling

[Tomswan]

As a few people who have already been very helpful will know, I have been at war with my boiler for some time. The pump has been locking repeatedly, and that despite the fact that I am on my third inside 12 months.

I got a tip that it might be micro air bubbles expanding and locking out the pumps, so I went and got a replacement isolation valve (where the flexible oil line connects to the incoming copper oil pipe inside the boiler) in case air was being drawn in through it when the pump was working.
When I took it off I found little bits of hard grit like substance in the shape of shards, and the residue of what looked to be a baked on pink washer on the end of the oil line. So I wondered if this was once a washer that had disintegrated and am asking if it is likely the installer would have used one with a compression fitting, given there's already an olive. If small bits were getting into the pump it might explain the binding, which I had supposed was air.

 

[Terrywookfit]

Copper washers were supplied for nipples with parallel threads sometimes.
Boulter Boilers especially so. I never had one fail though. They were meant for single use, but if annealed would last forever.
Is the gritty substance magnetically attracted.?

 

[Burnerman]

The only place you would find fibre washers are where there are flat flanges to be sealed....
Bleed screws on a filter bowl for example.
With compression fittings, the tapered olive is relied on, but liquid sealants are acceptable if necessary.
I’d suggest the debris came from further up the oil line.
If you suspect a coupling is allowing air in, you can plaster it with grease for a temporary seal - however kerosene is a great penetrating fluid and will always escape when it can and the smell and oil trace should be obvious.
John

 

[Tomswan]

The only place you would find fibre washers are where there are flat flanges to be sealed....
Bleed screws on a filter bowl for example.
With compression fittings, the tapered olive is relied on, but liquid sealants are acceptable if necessary.
I’d suggest the debris came from further up the oil line.
If you suspect a coupling is allowing air in, you can plaster it with grease for a temporary seal - however kerosene is a great penetrating fluid and will always escape when it can and the smell and oil trace should be obvious.
John

Thanks John. I did seem a bit unlikely. First thing I did when I decided to try to resolve this myself was change the in line filter, which I don't think had ever been changed during the annual 'services'. It was clogged black and oozing. But I didn't;t think there was anything further down the line closer to the burner because the oil was running clear. Then again, I suppose it would only take a tiny bit of hard debris to cause the pump to bind. Anyhow, it's running again now after changing the valve, and over net couple of weeks I will blow through the oil line back to the in line filter.

 

[oilhead]

Your pink shards may be some rogue jointing compound from further down the line, or it may have been used on the oil line which relies on the 'bullet' being tight on the face.

 

[Tomswan]

Copper washers were supplied for nipples with parallel threads sometimes.
Boulter Boilers especially so. I never had one fail though. They were meant for single use, but if annealed would last forever.
Is the gritty substance magnetically attracted.?

I don't know. I can check it when I disassemble again. Thanks.

 

[Tomswan]

Your pink shards may be some rogue jointing compound from further down the line, or it may have been used on the oil line which relies on the 'bullet' being tight on the face.

I would have thought the inline filter would catch them if they are further down the line, but I cannot be sure.

It has just conked again after only a couple of hours. The latest pump was tested for three days by the supplier before I got it, so it cannot be a dodgy pump. Oil is running clear. Same thing every time: runs for a while then stops. When I take it off it will be binding like before. I will get pliers on the spindle and rotate a couple of times to work it loose, then it will be ok again for short while. If it isn't air, and it isn't grit, and it isn't oil, and it isn't a dodgy pump, I am finally at a loss I think.

 

[Tomswan]

There is an upside, though. The upside is that this may well be the longest repair attempt in recorded history. I can nearly laugh about it. When I can finally laugh about it I will have overcome. Not the boiler, obviously, but my awful, awful rage and despair.

 

[snb]

Start at the basics.
clean or renew filter at the tank.
replace filter at filter bowl with a fine paper filter 10micron max
i assume the new oil pump cam with a new solenoid. if not replace solenoid ( when they start to fail they fail at 30-40mins and eventually fail after 5 mins down to complete failure)

When you fitted the new oil pump did you set the pump pressure and use an analyser to set it up correctly, because if you didn't all the above is a waste of time!

 

[oilhead]

Are you absolutely sure you don't have water in the oil? Bleed a litre or two off so that you get a representative sample and leave it to settle for a few hours. Also dip your tank with water finding paste. Since replacing your filter have you checked it again? your pumps may be binding through lack of oil from a blockage. start with your tank and check everything again.
I am bemused as to how your supplier could test a new pump for three days.

Cross posted with SNB above. (great minds???)

 

[Tomswan]

Start at the basics.
clean or renew filter at the tank.
replace filter at filter bowl with a fine paper filter 10micron max
i assume the new oil pump cam with a new solenoid. if not replace solenoid ( when they start to fail they fail at 30-40mins and eventually fail after 5 mins down to complete failure)

When you fitted the new oil pump did you set the pump pressure and use an analyser to set it up correctly, because if you didn't all the above is a waste of time!

All of there above but no analyser. The plan was to ensure it works ok then get someone in to service. I've already spent well over a grand on professionals and I am still without a working boiler. I'm only doing this because I don't much fancy paying someone more money to leave me with a bucket of bolts. I can do that myself. If I sound a bit miffed it is because I am. There is also no point telling me to get them back, since they won't return my calls, and when I eventually used another phone they agreed and didn't turn up. So I am done with that. I am sure there are fantastic boiler mechanics out there, but there is no way for me to know, and it is something of a lottery.

Of course if the mix being off can be responsible for the pump locking up, that's another matter, but I would like to know how, if so.

 

[Tomswan]

Are you absolutely sure you don't have water in the oil? Bleed a litre or two off so that you get a representative sample and leave it to settle for a few hours. Also dip your tank with water finding paste. Since replacing your filter have you checked it again? your pumps may be binding through lack of oil from a blockage. start with your tank and check everything again.
I am bemused as to how your supplier could test a new pump for three days.

Cross posted with SNB above. (great minds???)

It's the third pump in 12 months. How could all fail if the fault was in the pump?

Anyway: check for no water int eh oil - did it with paste.
check for drawing off oil and leaving it to settle for hours. Clear as a bell.
Check for 10 micron new filter in in line filter.
Pumps are bleeding ok, although I have been using the pressure test port to bleed rather than the vacuum port on the face, just because it is easier to get at. I can change that next time.

Anyhow, I took it off and same as before: locked tight. Spindle wouldn't move. Normally I'd just free it up but I decided to have a look inside.
Some grains of crap in the pump strainer, so just maybe clearing the feed back to the in line filter will do it.
However, when I took the second cap off (with the three small Allen bolts) and lifted it off, the pump immediately unlocked and turned. So I would have thought that would rule out a bit of grit in between the cogs.

So, I thought, the crescent shaped component in there would be at fault. When I put it back together and tightened down, it locked again. SO I undid the bolts a little and wiggled it (there is slight movement) and it immediately turned freely again. So I think that is the point where it is binding. I was able to lock down by tightening the bolts fractionally and turning the shaft in between turns, and that seems to have done it - it is moving freely with everything locked in place, and this time I didn't do it with a pair of pliers.

For all I know it is vibrational. Maybe the motor is somehow kicking through vibrations that are feeding into the pump and causing it to bind. If that's the case then I can buy new pumps from now until Christmas and get no result. How I test for that, though, I dod not know.

 

[Burnerman]

If this was mine Tom, I’d be losing the will to live.....
Is it a BFP pump you have, connected to which burner? Can you give us a pic of how the motor is coupled to the motor?
I’m a bit confused that the supplier ‘tested’ the pump for a while.....how did he do that?
The only problem I’ve had with the pump is how, on some models, it is connected to the burner.....on some it is possible to misalign them - but it still wouldn’t give your symptoms.
Maybe a bit extreme, but is it possible to couple up a seperate oil feed, from an oil drum perhaps?
John

 

[Tomswan]

If this was mine Tom, I’d be losing the will to live.....
Is it a BFP pump you have, connected to which burner? Can you give us a pic of how the motor is coupled to the motor?
I’m a bit confused that the supplier ‘tested’ the pump for a while.....how did he do that?
The only problem I’ve had with the pump is how, on some models, it is connected to the burner.....on some it is possible to misalign them - but it still wouldn’t give your symptoms.
Maybe a bit extreme, but is it possible to couple up a seperate oil feed, from an oil drum perhaps?
John

It's a riello pump connected to a riello burner attached to a Worcester Bosch boiler.
As for the testing, what happened was that they original guys I had in to fix it put in a new motor and new pump. Declared it all good and vamoosed. Did come back when it conked but after that I wasn't prepared to outlay any more cash when it went again. In any case, as I said, when I tried a couple of months ago they first ignored the call then failed to turn up, so I am done with them permanently. I realised they would just swap parts at my expense anyway until the problem resolved itself and God knows how far that would have gone. Anyhow, water under the bridge. So that was one new pump that failed. Then I ordered another new pump, and then that failed. So then I decided it might be a batch problem, and decided to get a refurbished one from a guy with very good feedback who tested it thoroughly for me before despatching. There didn't seem any point getting a third new one.
Anyhow, I am where I am.
It feels to me like some kind of misalignment problem. When I Tok it off the burner today the nylon coupler was stuck fast to the drive shaft on the pump and I had to lever it off. I guess that's because the motor didn't cut out in time and applied more torque this time (before it just came off easily).
The only thing that puzzles me a little is that that coupler has some play when it seats in the motor housing - you can waggle it. But I have a couple of them and the old motor and it was the same for each - both couplers waggle in both motors.

I suppose I feel like losing the will to live some time, but as I keep telling people who think I have lost my mind for still persevering, it is a mechanism. It cannot be trying to thwart me, it isn't 'refusing' to work. There is a fault that remains unidentified, and when it is identified it will be possible to effect a repair and move on. One day.

I've just checked the couplers again, this time on the pump shaft, and it seems the one that was on there has a lot more rotational give than the one that came off during the initial repair. So maybe every time the pump locks up it distorts the coupler a bit more until it is the coupler that causes the lock up. So it could lock up for one reason and then lock up for a different reason later, even after the first cause has been dealt with. Worth trying a brand new coupler, anyway.

 

[Burnerman]

For sure, pump failure is greatly hastened by poor fuel or filtering - it uses kero to lube the internals - and excess heat. Kero also disperses the heat.
I've always found the pump filter fine for doing it's job, providing it's clean of course.
I've had couplings fail due to age, contamination or heat but they haven't interfered with the pump at all.
If this was mine, I'd run the burner up on the bench with a separate fuel supply (I use a large Tupperware container with a lid and tap outlet)....crazy I know but I have this because on some installations it's not possible to adjust the pump when the burner is in place.
John