Discussion:
Pump coupling question for the boiler guys
(too old to reply)
BGBevill
2004-12-26 21:48:51 UTC
Hello,
This morning when I got to church, we had no heat. When we went to take a
look, we found a busted pump coupling. There were several spare rubber
couplings there, so we took it aloose, removed the broken rubber and replaced
it with one of the spares laying there and got it back to running. Upon going
back down stairs I asked about all the spare pump couplings and was told that
we are loosing one about every two weeks and the contractor leaves them for us
to change out in a pinch. I then ask has anyone mentioned what might be
causing us to loose a coupling every two weeks. I was told that our contractor
said he thought it was air and they were going to install another air vent to
remove the air and solve the problem. That is my question. I have been doing
light commercial heating and a/c for close to 20 years and have never heard of
air causing pump coupling to break. I looked at the alignment and everything
seemed to be okay. The thing ran without any vibration or anything once we got
it going. Most of my experience has been with the smaller B&G type couplings,
although I used to have two accounts that had large Taco pumps with rubber
couplings. Comments anyone?? Anyone had experience with air breaking pump
couplings?

thanks,
Bobby
Oscar_Lives
2004-12-26 21:52:38 UTC
Post by BGBevill
Hello,
This morning when I got to church, we had no heat. When we went to take a
look, we found a busted pump coupling. There were several spare rubber
couplings there, so we took it aloose, removed the broken rubber and replaced
it with one of the spares laying there and got it back to running. Upon going
back down stairs I asked about all the spare pump couplings and was told that
we are loosing one about every two weeks and the contractor leaves them for us
to change out in a pinch. I then ask has anyone mentioned what might be
causing us to loose a coupling every two weeks. I was told that our contractor
said he thought it was air and they were going to install another air vent to
remove the air and solve the problem. That is my question. I have been doing
light commercial heating and a/c for close to 20 years and have never heard of
air causing pump coupling to break. I looked at the alignment and everything
seemed to be okay. The thing ran without any vibration or anything once we got
it going. Most of my experience has been with the smaller B&G type couplings,
although I used to have two accounts that had large Taco pumps with rubber
couplings. Comments anyone?? Anyone had experience with air breaking pump
couplings?
thanks,
Bobby
Anyone check the alignment and the runout on the motor and the pump?
p***@see_my_sig_for_address.com
2004-12-26 22:00:05 UTC
Post by Oscar_Lives
Post by BGBevill
Hello,
This morning when I got to church, we had no heat. When we went to take a
look, we found a busted pump coupling. There were several spare rubber
couplings there, so we took it aloose, removed the broken rubber and replaced
it with one of the spares laying there and got it back to running. Upon going
back down stairs I asked about all the spare pump couplings and was told that
we are loosing one about every two weeks and the contractor leaves them for us
to change out in a pinch. I then ask has anyone mentioned what might be
causing us to loose a coupling every two weeks. I was told that our contractor
said he thought it was air and they were going to install another air vent to
remove the air and solve the problem. That is my question. I have been doing
light commercial heating and a/c for close to 20 years and have never heard of
air causing pump coupling to break. I looked at the alignment and everything
seemed to be okay. The thing ran without any vibration or anything once we got
it going. Most of my experience has been with the smaller B&G type couplings,
although I used to have two accounts that had large Taco pumps with rubber
couplings. Comments anyone?? Anyone had experience with air breaking pump
couplings?
thanks,
Bobby
Anyone check the alignment and the runout on the motor and the pump?
Exactly. And bearing tightness on the pump.

The air story is BS. Excessive start torque / resistance, or
mis-alignment are what do it, not air.

I would also, in the circumstance, want to know that the pump,
the coupling set, and the motor are a correct match and not some
field rig.



Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'

HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/
~KJPRO~
2004-12-26 22:12:13 UTC
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
Hello,
This morning when I got to church, we had no heat. When we went to
take
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
a
look, we found a busted pump coupling. There were several spare rubber
couplings there, so we took it aloose, removed the broken rubber and replaced
it with one of the spares laying there and got it back to running.
Upon
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
going
back down stairs I asked about all the spare pump couplings and was
told
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
that
we are loosing one about every two weeks and the contractor leaves them for us
to change out in a pinch. I then ask has anyone mentioned what might be
causing us to loose a coupling every two weeks. I was told that our contractor
said he thought it was air and they were going to install another air
vent
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
to
remove the air and solve the problem. That is my question. I have
been
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
doing
light commercial heating and a/c for close to 20 years and have never heard of
air causing pump coupling to break. I looked at the alignment and everything
seemed to be okay. The thing ran without any vibration or anything
once
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
we got
it going. Most of my experience has been with the smaller B&G type couplings,
although I used to have two accounts that had large Taco pumps with rubber
couplings. Comments anyone?? Anyone had experience with air breaking pump
couplings?
thanks,
Bobby
Anyone check the alignment and the runout on the motor and the pump?
Exactly. And bearing tightness on the pump.
This would be my guess.

It probably gets tight after running and then is fine after you put the
coupling back together.

~kjpro~
Post by p***@see_my_sig_for_address.com
The air story is BS. Excessive start torque / resistance, or
mis-alignment are what do it, not air.
I would also, in the circumstance, want to know that the pump,
the coupling set, and the motor are a correct match and not some
field rig.
'Some days, it's just not worth chewing through the restraints.'
HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
Free Temperature / Pressure charts for 38 Ref's
http://pmilligan.net/pmtherm/
Oscar_Lives
2004-12-26 22:17:04 UTC
Post by BGBevill
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
Hello,
This morning when I got to church, we had no heat. When we went to
take
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
a
look, we found a busted pump coupling. There were several spare rubber
couplings there, so we took it aloose, removed the broken rubber and replaced
it with one of the spares laying there and got it back to running.
Upon
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
going
back down stairs I asked about all the spare pump couplings and was
told
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
that
we are loosing one about every two weeks and the contractor leaves
them
for us
to change out in a pinch. I then ask has anyone mentioned what might
be
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
causing us to loose a coupling every two weeks. I was told that our contractor
said he thought it was air and they were going to install another air
vent
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
to
remove the air and solve the problem. That is my question. I have
been
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
doing
light commercial heating and a/c for close to 20 years and have never heard of
air causing pump coupling to break. I looked at the alignment and everything
seemed to be okay. The thing ran without any vibration or anything
once
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
we got
it going. Most of my experience has been with the smaller B&G type couplings,
although I used to have two accounts that had large Taco pumps with
rubber
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
couplings. Comments anyone?? Anyone had experience with air breaking pump
couplings?
thanks,
Bobby
Anyone check the alignment and the runout on the motor and the pump?
Exactly. And bearing tightness on the pump.
This would be my guess.
It probably gets tight after running and then is fine after you put the
coupling back together.
~kjpro~
I had a wife like that...
Post by BGBevill
Post by p***@see_my_sig_for_address.com
The air story is BS. Excessive start torque / resistance, or
mis-alignment are what do it, not air.
I would also, in the circumstance, want to know that the pump,
the coupling set, and the motor are a correct match and not some
field rig.
'Some days, it's just not worth chewing through the restraints.'
HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
Free Temperature / Pressure charts for 38 Ref's
http://pmilligan.net/pmtherm/
p***@see_my_sig_for_address.com
2004-12-26 22:19:52 UTC
Post by BGBevill
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
Hello,
This morning when I got to church, we had no heat. When we went to
take
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
a
look, we found a busted pump coupling. There were several spare rubber
couplings there, so we took it aloose, removed the broken rubber and replaced
it with one of the spares laying there and got it back to running.
Upon
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
going
back down stairs I asked about all the spare pump couplings and was
told
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
that
we are loosing one about every two weeks and the contractor leaves them for us
to change out in a pinch. I then ask has anyone mentioned what might
be
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
causing us to loose a coupling every two weeks. I was told that our contractor
said he thought it was air and they were going to install another air
vent
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
to
remove the air and solve the problem. That is my question. I have
been
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
doing
light commercial heating and a/c for close to 20 years and have never heard of
air causing pump coupling to break. I looked at the alignment and everything
seemed to be okay. The thing ran without any vibration or anything
once
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
we got
it going. Most of my experience has been with the smaller B&G type couplings,
although I used to have two accounts that had large Taco pumps with
rubber
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Post by BGBevill
couplings. Comments anyone?? Anyone had experience with air breaking pump
couplings?
thanks,
Bobby
Anyone check the alignment and the runout on the motor and the pump?
Exactly. And bearing tightness on the pump.
This would be my guess.
It probably gets tight after running and then is fine after you put the
coupling back together.
Also, if there are any shock absorbers / springs / etc on the
motor or the pump mounts themselves, they need to be right.



Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'

HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/
Jake
2004-12-26 22:47:07 UTC
Post by p***@see_my_sig_for_address.com
Also, if there are any shock absorbers / springs / etc on the
motor or the pump mounts themselves, they need to be right.
Yep... I forgot about that. We had a troubleshoot one time where some plant
maintenance people set a replacement motor in (probably 50 horse or so) and
that thing was chewing up coupling inserts every two or three days. They
just kept changing them and telling the people there "We must got a bad
batch of inserts".

When I got to checking, though, I found OEM shims laying on the ground
nearby. I asked, "Where'd these come from?". When they changed the motor,
they never put the shims back under the feet. Measuring the alignment with a
laser showed about a 1/32 inch side/side misalignment and nearly double that
up/down. Oh, they didn't put the coupling cover back on, either.

Sometimes you've just gotta know what to look for (-;... like parts on the
floor instead of on the machine!

Jake
p***@see_my_sig_for_address.com
2004-12-26 23:18:29 UTC
Post by Jake
Post by p***@see_my_sig_for_address.com
Also, if there are any shock absorbers / springs / etc on the
motor or the pump mounts themselves, they need to be right.
Yep... I forgot about that. We had a troubleshoot one time where some plant
maintenance people set a replacement motor in (probably 50 horse or so) and
that thing was chewing up coupling inserts every two or three days. They
just kept changing them and telling the people there "We must got a bad
batch of inserts".
Geez, where have I heard THAT one before ?? :-(
Post by Jake
When I got to checking, though, I found OEM shims laying on the ground
nearby. I asked, "Where'd these come from?". When they changed the motor,
they never put the shims back under the feet. Measuring the alignment with a
laser showed about a 1/32 inch side/side misalignment and nearly double that
up/down. Oh, they didn't put the coupling cover back on, either.
Probably either didn't fit any more without rubbing, or it
shook itself
off :-)
Post by Jake
Sometimes you've just gotta know what to look for (-;... like parts on the
floor instead of on the machine!
Yeh, and 'dialing in is good' :-)




Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'

HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/
Jake
2004-12-27 00:32:15 UTC
Post by p***@see_my_sig_for_address.com
Yeh, and 'dialing in is good' :-)
Dialing in is good, but we use this for the big, expensive stuff:

http://www.hamarlaser.com/systems/s640/640rotoaltsys_3910.htm

It ain't cheap, but neither is replacing a big fan, pump or screw compressor
if you mess up the alignment (-;.

Jake

BTW, my accountant will probably still be depreciating that setup after I'm
dead )-:.
p***@see_my_sig_for_address.com
2004-12-27 00:48:11 UTC
Post by Jake
Post by p***@see_my_sig_for_address.com
Yeh, and 'dialing in is good' :-)
http://www.hamarlaser.com/systems/s640/640rotoaltsys_3910.htm
It ain't cheap, but neither is replacing a big fan, pump or screw compressor
if you mess up the alignment (-;.
Jake
BTW, my accountant will probably still be depreciating that setup after I'm
dead )-:.
Damn. I was issued one of these for that stuff.

http://tinyurl.com/5r82n

'Old ways' you know :-)

I remember one pair of 150 HP's I was called out on, I could
literally tell from across the room that they were out, even sitting
there off. Damn pulleys were worn so bad from it, the outer edges
were practically worn through. And they couldn't figure out why nice
new matched sets of 150 " belts tended to last about a week ( of
squealling like a pig ) :-)



Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'

HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/
Jake
2004-12-27 01:22:45 UTC
Post by p***@see_my_sig_for_address.com
'Old ways' you know :-)
I remember one pair of 150 HP's I was called out on, I could
literally tell from across the room that they were out, even sitting
there off. Damn pulleys were worn so bad from it, the outer edges
were practically worn through. And they couldn't figure out why nice
new matched sets of 150 " belts tended to last about a week ( of
squealling like a pig ) :-)
Heck, the thing they do now is hang a "Power Band" belt on something like
that. Costs a little more than the single belts, but Boy, it'll last 4-6
weeks before it throws that big sum-bitch clear through a window or
something (-;.

Jake
Tekkie
2004-12-27 02:32:35 UTC
posted for all of us....
Post by p***@see_my_sig_for_address.com
http://tinyurl.com/5r82n
Hmmm, calibrated eyeballs
--
Tekkie
Tekkie
2004-12-27 02:29:34 UTC
Jake posted for all of us....
Post by Jake
Post by p***@see_my_sig_for_address.com
Also, if there are any shock absorbers / springs / etc on the
motor or the pump mounts themselves, they need to be right.
Yep... I forgot about that. We had a troubleshoot one time where some plant
maintenance people set a replacement motor in (probably 50 horse or so) and
that thing was chewing up coupling inserts every two or three days. They
just kept changing them and telling the people there "We must got a bad
batch of inserts".
When I got to checking, though, I found OEM shims laying on the ground
nearby. I asked, "Where'd these come from?". When they changed the motor,
they never put the shims back under the feet. Measuring the alignment with a
laser showed about a 1/32 inch side/side misalignment and nearly double that
up/down. Oh, they didn't put the coupling cover back on, either.
Sometimes you've just gotta know what to look for (-;... like parts on the
floor instead of on the machine!
Jake
This leads to my question: How does one tell the alignment is correct? My
recollection is there isn't a lot of room in there when assembled. Then
again WTF do I know.
--
Tekkie
Oscar_Lives
2004-12-27 04:52:22 UTC
Post by Jake
Post by p***@see_my_sig_for_address.com
Also, if there are any shock absorbers / springs / etc on the
motor or the pump mounts themselves, they need to be right.
Yep... I forgot about that. We had a troubleshoot one time where some
plant maintenance people set a replacement motor in (probably 50 horse or
so) and that thing was chewing up coupling inserts every two or three
days. They just kept changing them and telling the people there "We must
got a bad batch of inserts".
When I got to checking, though, I found OEM shims laying on the ground
nearby. I asked, "Where'd these come from?". When they changed the motor,
they never put the shims back under the feet. Measuring the alignment with
a laser showed about a 1/32 inch side/side misalignment and nearly double
that up/down. Oh, they didn't put the coupling cover back on, either.
Sometimes you've just gotta know what to look for (-;... like parts on the
floor instead of on the machine!
Jake
I hate to say it, but our union millwrights all get motor/coupler alignment
training on the latest equipment and with the old-fashioned dial-indicator
and calculator methods.

Better call a union millwright for this one.
TURTLE
2004-12-27 06:52:43 UTC
Post by Jake
Post by p***@see_my_sig_for_address.com
Also, if there are any shock absorbers / springs / etc on the
motor or the pump mounts themselves, they need to be right.
Yep... I forgot about that. We had a troubleshoot one time where some plant
maintenance people set a replacement motor in (probably 50 horse or so) and
that thing was chewing up coupling inserts every two or three days. They just
kept changing them and telling the people there "We must got a bad batch of
inserts".
When I got to checking, though, I found OEM shims laying on the ground nearby.
I asked, "Where'd these come from?". When they changed the motor, they never
put the shims back under the feet. Measuring the alignment with a laser showed
about a 1/32 inch side/side misalignment and nearly double that up/down. Oh,
they didn't put the coupling cover back on, either.
Sometimes you've just gotta know what to look for (-;... like parts on the
floor instead of on the machine!
Jake
this is Turtle

I bet you one of them there laser tools would tell you exactly what it was off
at and make some smooth running motors and pumps. With a 32 th side to side and
16 th up and down , they must have used a folding up tape measurer and forgot
their tools at the house.

Them 50 Horses will be wanting to rare up real bad on a 1/16th.

TURTLE
Dr. Hardcrab
2004-12-27 13:49:33 UTC
Post by p***@see_my_sig_for_address.com
Also, if there are any shock absorbers / springs / etc on the
motor or the pump mounts themselves, they need to be right.
I think that model has gas struts.....
Jake
2004-12-26 22:33:35 UTC
I'd be willing to bet that its alignment or run-out, too, but you'd really
need a better description of the type of coupling (those small Falk
couplings are notorious for being very finicky about alignment but not
run-out so much) and how it's failing.

The motor, coupling mating and the pump all need checked by somebody other
than the folks telling you "It's the air". They obviously don't have a
clue...

Jake
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Anyone check the alignment and the runout on the motor and the pump?
Exactly. And bearing tightness on the pump.
The air story is BS. Excessive start torque / resistance, or
mis-alignment are what do it, not air.
I would also, in the circumstance, want to know that the pump,
the coupling set, and the motor are a correct match and not some
field rig.
BGBevill
2004-12-27 00:58:31 UTC
Post by Jake
I'd be willing to bet that its alignment or run-out, too, but you'd really
need a better description of the type of coupling (those small Falk
couplings are notorious for being very finicky about alignment but not
run-out so much) and how it's failing.
The motor, coupling mating and the pump all need checked by somebody other
than the folks telling you "It's the air". They obviously don't have a
clue...
Jake
The rubber insert in the coupling is a Lovejoy 1L790. The one this morning was
sheared off just like I would expect should the pump lock up for some reason.
I am not familiar with this brand coupling at all and as I said earlier, my
experience is pretty much limited to B&G stuff. The air story got my attention
because is was a new one on me. Something else that got my attention is that
there are 3 identical pumps and motors. If air is breaking one, my question
would be why are the other two doing just fine in the same system? Oh well,
the air story just ran up a red flag and I figured someone here might have
heard it, if there was anything to it.

Bobby
Post by Jake
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Anyone check the alignment and the runout on the motor and the pump?
Exactly. And bearing tightness on the pump.
The air story is BS. Excessive start torque / resistance, or
mis-alignment are what do it, not air.
I would also, in the circumstance, want to know that the pump,
the coupling set, and the motor are a correct match and not some
field rig.
Jake
2004-12-27 01:17:20 UTC
Post by BGBevill
The rubber insert in the coupling is a Lovejoy 1L790. The one this morning was
sheared off just like I would expect should the pump lock up for some reason.
The Lovejoys are very similar to the Falks in design, at least in the flex
EPDM rubber insert series.

What do you mean "sheared off"... like sheared in the middle or one set of
the teeth on the insert?
Post by BGBevill
Something else that got my attention is that
there are 3 identical pumps and motors. If air is breaking one, my question
would be why are the other two doing just fine in the same system? Oh well,
the air story just ran up a red flag and I figured someone here might have
heard it, if there was anything to it.
Bobby
I've never heard of that, and I do commercial motors a lot. The coupling is
not for shear protection, it's there to compensate for minor misalignment
problems, and equipment vibration. If the pump itself was locking up, I'd
guess you'd get a motor overload trip long before you sheared a coupling.

The coupling insert you mentioned is pretty small... 120 inch-pounds
rated... what size motor and what kind of pump is it mated to?

The air story is BS... something else is wrong, IMO...

Jake
BGBevill
2004-12-27 01:48:23 UTC
Post by Jake
Post by BGBevill
The rubber insert in the coupling is a Lovejoy 1L790. The one this morning was
sheared off just like I would expect should the pump lock up for some reason.
The Lovejoys are very similar to the Falks in design, at least in the flex
EPDM rubber insert series.
What do you mean "sheared off"... like sheared in the middle or one set of
the teeth on the insert?
The teeth in the motor part of the coupling were broke off of the rest of the
insert. Almost like someone cut it with a hack saw or something. The rest of
the coupling was intact.
Post by Jake
Post by BGBevill
Something else that got my attention is that
there are 3 identical pumps and motors. If air is breaking one, my question
would be why are the other two doing just fine in the same system? Oh well,
the air story just ran up a red flag and I figured someone here might have
heard it, if there was anything to it.
Bobby
I've never heard of that, and I do commercial motors a lot. The coupling is
not for shear protection, it's there to compensate for minor misalignment
problems, and equipment vibration. If the pump itself was locking up, I'd
guess you'd get a motor overload trip long before you sheared a coupling.
The coupling insert you mentioned is pretty small... 120 inch-pounds
rated... what size motor and what kind of pump is it mated to?
I'll have to get back to you on that. I'd guess maybe a 2 hp motor, not really
large, but I was in a hurry to get it up and running and get back down with the
family. I can get the motor and pump info tomorrow and post it. And yeah,
that was one thing I thought about, the coupling insert is small for sure. I
guess it could be something that simple. Thanks for your input.
Post by Jake
The air story is BS... something else is wrong, IMO...
Jake
john
2004-12-27 04:46:54 UTC
Post by Jake
Post by BGBevill
The rubber insert in the coupling is a Lovejoy 1L790. The one this morning was
sheared off just like I would expect should the pump lock up for some reason.
The Lovejoys are very similar to the Falks in design, at least in the flex
EPDM rubber insert series.
What do you mean "sheared off"... like sheared in the middle or one set of
the teeth on the insert?
Post by BGBevill
Something else that got my attention is that
there are 3 identical pumps and motors. If air is breaking one, my question
would be why are the other two doing just fine in the same system? Oh well,
the air story just ran up a red flag and I figured someone here might have
heard it, if there was anything to it.
Bobby
I've never heard of that, and I do commercial motors a lot. The coupling is
not for shear protection, it's there to compensate for minor misalignment
problems, and equipment vibration. If the pump itself was locking up, I'd
guess you'd get a motor overload trip long before you sheared a coupling.
The coupling insert you mentioned is pretty small... 120 inch-pounds
rated... what size motor and what kind of pump is it mated to?
The air story is BS... something else is wrong, IMO...
Jake
If it sheared off the coupling halfs are moving apart because the set
screw is not properly set. IF the setscrew is backing out there is
probaly also a mis alignment of the two shafts. Make sure that there
is only one setscrew in each hole when you tighten them, you can put a
locking set screw on top of the first one but that confuses the average
mechanic. Its common in heavy machinery.

JOhn
geomanjr
2004-12-27 02:06:50 UTC
Bobby look at the rear rubber mount on the motor- that is usually where they
wear and start to sag causing a mis-alignment. I have seen this many times
and it will eat couplings like crazy. Just a thought, Mark
Post by BGBevill
Post by Jake
I'd be willing to bet that its alignment or run-out, too, but you'd really
need a better description of the type of coupling (those small Falk
couplings are notorious for being very finicky about alignment but not
run-out so much) and how it's failing.
The motor, coupling mating and the pump all need checked by somebody other
than the folks telling you "It's the air". They obviously don't have a
clue...
Jake
The rubber insert in the coupling is a Lovejoy 1L790. The one this morning was
sheared off just like I would expect should the pump lock up for some reason.
I am not familiar with this brand coupling at all and as I said earlier, my
experience is pretty much limited to B&G stuff. The air story got my attention
because is was a new one on me. Something else that got my attention is that
there are 3 identical pumps and motors. If air is breaking one, my question
would be why are the other two doing just fine in the same system? Oh well,
the air story just ran up a red flag and I figured someone here might have
heard it, if there was anything to it.
Bobby
Post by Jake
Post by p***@see_my_sig_for_address.com
Post by Oscar_Lives
Anyone check the alignment and the runout on the motor and the pump?
Exactly. And bearing tightness on the pump.
The air story is BS. Excessive start torque / resistance, or
mis-alignment are what do it, not air.
I would also, in the circumstance, want to know that the pump,
the coupling set, and the motor are a correct match and not some
field rig.
Jake
2004-12-27 21:49:54 UTC
Post by geomanjr
Bobby look at the rear rubber mount on the motor- that is usually where
they wear and start to sag causing a mis-alignment. I have seen this many
times and it will eat couplings like crazy. Just a thought, Mark
I think that's a good idea, Mark. I've seen it a few times, too... on the
rear corner (mostly) that is in line with downward rotation forces.

Jake
PrecisionMachinisT
2004-12-27 04:05:31 UTC
Post by BGBevill
Post by Jake
I'd be willing to bet that its alignment or run-out, too, but you'd really
need a better description of the type of coupling (those small Falk
couplings are notorious for being very finicky about alignment but not
run-out so much) and how it's failing.
The motor, coupling mating and the pump all need checked by somebody other
than the folks telling you "It's the air". They obviously don't have a
clue...
Jake
The rubber insert in the coupling is a Lovejoy 1L790. The one this morning was
sheared off just like I would expect should the pump lock up for some reason.
I am not familiar with this brand coupling at all and as I said earlier, my
experience is pretty much limited to B&G stuff. The air story got my attention
because is was a new one on me. Something else that got my attention is that
there are 3 identical pumps and motors. If air is breaking one, my question
would be why are the other two doing just fine in the same system? Oh well,
the air story just ran up a red flag and I figured someone here might have
heard it, if there was anything to it.
Bobby
I like to use the oldham type couplers whenever possible, with a delrin
disc, its very doubtful they would shear even if the pump has completely
locked up.

Dunno if they are in common use for pump shaft coupling, but here is a link:

< http://servovision.com/MM/N147/HUCO/hoco.html >
--
SVL
Tekkie
2004-12-29 02:55:20 UTC
PrecisionMachinisT posted for all of us....
Post by PrecisionMachinisT
< http://servovision.com/MM/N147/HUCO/hoco.html >
Hmmmm, stiffness index. I think my dick is a negative 3.79
--
Tekkie
PrecisionMachinisT
2004-12-29 03:00:27 UTC
Post by Tekkie
PrecisionMachinisT posted for all of us....
Post by PrecisionMachinisT
< http://servovision.com/MM/N147/HUCO/hoco.html >
Hmmmm, stiffness index. I think my dick is a negative 3.79
Definately some exciting stuff then, eh ???
--
SVL
BGBevill
2004-12-26 22:17:15 UTC
Post by Oscar_Lives
Anyone check the alignment and the runout on the motor and the pump?
Supposedly, the contractor has checked all that, but I haven't personally.
Just had the question about the air because I have never run into that before.

Bobby
TURTLE
2004-12-27 01:41:13 UTC
Post by BGBevill
Post by Oscar_Lives
Anyone check the alignment and the runout on the motor and the pump?
Supposedly, the contractor has checked all that, but I haven't personally.
Just had the question about the air because I have never run into that before.
Bobby
This is Turtle.

I use to take care of driver pumps on the offshore rigs and there was 4 things
that took out a A star rubber or Dodger coupling 1 h.p. to 300 h.p.. motors.
1) Bad Alinement motor verses the pump.
2) Bad Bearing on the pump or motor causing miss alinment at times of heavy
use.
3) The Back end of the motor is not perfectly alined to the pump shaft but
ever so slite but you can still dial in the alinement but it will be just a hair
off which a lot of millright will let go. This will set up a shifting of the
rubber bushing from 180º and 360º back and forth. It will take 10 to 90 days to
eat the star or Dodger coupling up.
3) The pump Jams or freezes up. So Don't pump Welding rods.


There is no place for any difference in the fluid it may pump for these pumps
pump air, sea water, oil, small fish, shrimp, and all kinds of odd stuff and
pump them all together and never strip a Dodges or star. The pump can go from
dry air to oil to water or combo of all and the rubber or Dodger is made to take
that shift. Also pump is not jamming if it runs more than a hour in full load
after bearing heat up but exception of the occussional welding rod.

So if they are not pumping welding rods the aliniment is off.

TURTLE
BGBevill
2004-12-27 02:32:39 UTC
Post by TURTLE
3) The Back end of the motor is not perfectly alined to the pump shaft but
ever so slite but you can still dial in the alinement but it will be just a hair
off which a lot of millright will let go. This will set up a shifting of the
rubber bushing from 180º and 360º back and forth. It will take 10 to 90 days to
eat the star or Dodger coupling up.
So if they are not pumping welding rods the aliniment is off.
TURTLE
You may be on to something. I made mention while changing the insert that it
looked like to me that the back end of the motor needed to be shifted over a
bit, but I was told all that had been checked. I'll probably get back by there
tomorrow sometime with some tools and take a closer look and get the numbers
off the motor and pump.

thanks,
Bobby
TURTLE
2004-12-27 06:30:34 UTC
Post by BGBevill
Post by TURTLE
3) The Back end of the motor is not perfectly alined to the pump shaft but
ever so slite but you can still dial in the alinement but it will be just a hair
off which a lot of millright will let go. This will set up a shifting of the
rubber bushing from 180º and 360º back and forth. It will take 10 to 90 days to
eat the star or Dodger coupling up.
So if they are not pumping welding rods the aliniment is off.
TURTLE
You may be on to something. I made mention while changing the insert that it
looked like to me that the back end of the motor needed to be shifted over a
bit, but I was told all that had been checked. I'll probably get back by there
tomorrow sometime with some tools and take a closer look and get the numbers
off the motor and pump.
thanks,
Bobby
This is Turtle.

You don't need any tools to tell a V butt . The motor and the pump makes a V
shaped look to it and offshore they called it a V butt skid. Just look from the
motor end back about 10 feet and you can see it like a road sign that says V
Butt motor here.

Now here comes the Hackish way here of some of the pumper offshore would do.
Loosen up the back two bolts holding it just a little when it can move a little
but not much and just one up front on the motor closest to the pump. Then run
the motor till it comes up to full speed and then cut it off. Sometimes the butt
will come back around and line up pretty close. Then tighten it back up and see
with your mike to see the alinement of it. This will only take care of left to
right and do nothing for up and down alinement. This is really for a motor that
was set perfectly at one time and you pull the pump to clean it out and replace
it. Now if you loosen all 4 bolts of the motor it may leave there and you
watching it leave. Now the best is to reset it and do a perfect job the first
time but use this in a bind and you need the pump running Now and not later.
Now if in dought here. Don't do nothing like this and just aline it right the
hard way with a 16 pound sledge and one eye closed. Do you do your millrighting
yourself or do you call in a Millright?

TURTLE
Bubba
2004-12-26 22:37:52 UTC
Post by BGBevill
Hello,
This morning when I got to church, we had no heat. When we went to take a
look, we found a busted pump coupling. There were several spare rubber
couplings there, so we took it aloose, removed the broken rubber and replaced
it with one of the spares laying there and got it back to running. Upon going
back down stairs I asked about all the spare pump couplings and was told that
we are loosing one about every two weeks and the contractor leaves them for us
to change out in a pinch. I then ask has anyone mentioned what might be
causing us to loose a coupling every two weeks. I was told that our contractor
said he thought it was air and they were going to install another air vent to
remove the air and solve the problem. That is my question. I have been doing
light commercial heating and a/c for close to 20 years and have never heard of
air causing pump coupling to break. I looked at the alignment and everything
seemed to be okay. The thing ran without any vibration or anything once we got
it going. Most of my experience has been with the smaller B&G type couplings,
although I used to have two accounts that had large Taco pumps with rubber
couplings. Comments anyone?? Anyone had experience with air breaking pump
couplings?
thanks,
Bobby
Does this motor have rubber motor mounts on each end? If so, change
them.
Bubba
Mark Schofield
2004-12-27 18:19:34 UTC
on the B&G package or instruction sheet for the smaller butterfly/spring
metal couplers, it says somewhere that the primary cause of coupling failure
is bad motor mounts. the rubber mounts mentioned in the previous post. or
how about the spot welds holding the motor to the frame which connects to
the bearing assembly.
Post by Bubba
Post by BGBevill
Hello,
This morning when I got to church, we had no heat. When we went to take a
look, we found a busted pump coupling. There were several spare rubber
couplings there, so we took it aloose, removed the broken rubber and replaced
it with one of the spares laying there and got it back to running. Upon going
back down stairs I asked about all the spare pump couplings and was told that
we are loosing one about every two weeks and the contractor leaves them for us
to change out in a pinch. I then ask has anyone mentioned what might be
causing us to loose a coupling every two weeks. I was told that our contractor
said he thought it was air and they were going to install another air vent to
remove the air and solve the problem. That is my question. I have been doing
light commercial heating and a/c for close to 20 years and have never heard of
air causing pump coupling to break. I looked at the alignment and everything
seemed to be okay. The thing ran without any vibration or anything once we got
it going. Most of my experience has been with the smaller B&G type couplings,
although I used to have two accounts that had large Taco pumps with rubber
couplings. Comments anyone?? Anyone had experience with air breaking pump
couplings?
thanks,
Bobby
Does this motor have rubber motor mounts on each end? If so, change
them.
Bubba
Dr. Hardcrab
2004-12-27 19:14:52 UTC
Post by Mark Schofield
on the B&G package or instruction sheet for the smaller butterfly/spring
metal couplers, it says somewhere that the primary cause of coupling
failure is bad motor mounts. the rubber mounts mentioned in the previous
post. or how about the spot welds holding the motor to the frame which
connects to the bearing assembly.
I am not sure of the brand, just the R.E.Michels number (1W100), but I use
those spring type couplers: brass ends connected by a spring. Never have any
problems with them and have never seen one break (except one where the pump
locked up, and, I guess it's SUPPOSED to break....)
Stormin Mormon
2004-12-27 00:38:24 UTC
do you mean from the shaft of the motor to the shaft of the pump? The only
one's of those I've seen have been metal gadgets with four pieces of metal
(or more?) and four springs. Maybe a rubber coupler is inadequate for the
job?
--
Christopher A. Young
Keep Jesus Christ in CHRISTmas
www.lds.org
www.mormons.com


"BGBevill" <***@aol.comnojunk> wrote in message news:***@mb-m13.aol.com...
Hello,
This morning when I got to church, we had no heat. When we went to take a
look, we found a busted pump coupling. There were several spare rubber
couplings there, so we took it aloose, removed the broken rubber and
replaced
it with one of the spares laying there and got it back to running. Upon
going
back down stairs I asked about all the spare pump couplings and was told
that
we are loosing one about every two weeks and the contractor leaves them for
us
to change out in a pinch. I then ask has anyone mentioned what might be
causing us to loose a coupling every two weeks. I was told that our
contractor
said he thought it was air and they were going to install another air vent
to
remove the air and solve the problem. That is my question. I have been
doing
light commercial heating and a/c for close to 20 years and have never heard
of
air causing pump coupling to break. I looked at the alignment and
everything
seemed to be okay. The thing ran without any vibration or anything once we
got
it going. Most of my experience has been with the smaller B&G type
couplings,
although I used to have two accounts that had large Taco pumps with rubber
couplings. Comments anyone?? Anyone had experience with air breaking pump
couplings?

thanks,
Bobby