Parallelling fuel pumps
 

So perhaps a valve on both ends plus a check valve or maybe
two check valves. This is getting too complicated to be
worth it.

Doug
s/v Callista

"Rich Hampel" wrote in message
...
Further thoughts against paralleling such pumps:
If the internal check valves in one pump fails then the fluid will
flow retrograde in the pump that failed.... and damn little volume is
pumped by the pump that remains intact.
Typical industrial installation of such a 'system' would require a
block and bypass system of cocks/valves and bypass/lock-out piping.

In article , Steven Shelikoff
wrote:

On Mon, 12 Apr 2004 13:33:26 -0000, Larry W4CSC wrote:

(Steven Shelikoff) wrote in
:


That begs the question why are you going to put two pumps in parallel
if
you only want to run one at a time?

Steve


Backup?

Then I wouldn't put them in parallel without isolation valves. Even if
it works when both pumps are good, you don't know how the pump will
fail.

Steve

Parallelling fuel pumps
 

"David Flew" wrote in message
...
Steve
Exactly what does the spec say? Is it NPSH ( nett positive suction head)
of
1 ft? Or is it max lift of one foot? It almost sounds like a self
priming
manual pump of some sort might be the go.
DF

This was an AC pulse type electric pump I got at the autoparts store. It's
on the boat, haven't installed it yet. But I think it said Max. Suction Lift
is one foot.

I'm going to check it when I go there later today.

Steve
s/v Good Intentions

Parallelling fuel pumps
 

"David Flew" wrote in message
...
Steve
Exactly what does the spec say? Is it NPSH ( nett positive suction head)
of
1 ft? Or is it max lift of one foot? It almost sounds like a self
priming
manual pump of some sort might be the go.
DF

This was an AC pulse type electric pump I got at the autoparts store. It's
on the boat, haven't installed it yet. But I think it said Max. Suction Lift
is one foot.

I'm going to check it when I go there later today.

Steve
s/v Good Intentions

Parallelling fuel pumps
 

You got the same ones as we have,Doug. Yes, you have to bend the
mounting bracket drastically. Pry off the end caps and the clam shell
protection comes apart, exposing the pump. Remove three(?) screws on
the bottom plate to expose the filter.
http://www.autoperformanceengineerin...6000_pump.html


On Tue, 13 Apr 2004 11:48:16 -0400, "Doug Dotson"
wrote:

It appears these do not. Just to remove the mounting bracket
one would have to bend it out of shape quite drastically. I looked
closely at the brass caps top and bottom and it does appear that
they may be able to be pryed off. But in any case the instructions
say the filters are not servicable and there are no spares or
instructions for servicing provided.

Doug
s/v Callista

"Rich Hampel" wrote in message
...
Must be a 'new' version as all my Walbro pumps have
accessible/removalbe/cleanable protection screens/strainer wire.

In article , Doug Dotson
wrote:

Both my WALBRO pumps came with no replacement filters. A
large box in bold print in the instructions states the following:

" SERVICE DATA
The Walbro Marine Electronic Pump incorporates
two (2) built-in filters, one for filtering fine particles
and the other (a magnet) for trapping metalic
particles. Due to the construction of the protective
outer shell, these filters cannot be serviced."

The plastic outer shell appears to be glued together.
Perhaps this is a newer or different model than the
one you have.

Doug
s/v Callista

:
"Marc" wrote in message
...
The internal filter on the Walbro can be cleaned. In fact, they supply
a spare with the pump. Taking the pump apart is a little fussy in an
emergency situation. I am a little concerned to find out that a pump
failure may result in a blocked fuel supply due to the wobble plate.
Right now, I have the Walbro in line with my mechanical pump.


On Mon, 12 Apr 2004 17:55:34 -0400, "Doug Dotson"
wrote:

I seem to recall from the WALBRO docs that the pump is not
field servicable. Specifically, it states that the internal filters
cannot be changed.

Doug
s/v Callista

"Kelton Joyner" wrote in message
. ..
Unless you have isolation valves to allow servicing of a parallel
pump,
series works just as well for backup.
fuel wil flow through the unpowered pump.
Kelton
W4IND
s/v Isle Escape

Larry W4CSC wrote:
(Steven Shelikoff) wrote in
:


That begs the question why are you going to put two pumps in
parallel
if
you only want to run one at a time?

Steve



Backup?

Larry W4CSC

Parallelling fuel pumps
 

You got the same ones as we have,Doug. Yes, you have to bend the
mounting bracket drastically. Pry off the end caps and the clam shell
protection comes apart, exposing the pump. Remove three(?) screws on
the bottom plate to expose the filter.
http://www.autoperformanceengineerin...6000_pump.html


On Tue, 13 Apr 2004 11:48:16 -0400, "Doug Dotson"
wrote:

It appears these do not. Just to remove the mounting bracket
one would have to bend it out of shape quite drastically. I looked
closely at the brass caps top and bottom and it does appear that
they may be able to be pryed off. But in any case the instructions
say the filters are not servicable and there are no spares or
instructions for servicing provided.

Doug
s/v Callista

"Rich Hampel" wrote in message
...
Must be a 'new' version as all my Walbro pumps have
accessible/removalbe/cleanable protection screens/strainer wire.

In article , Doug Dotson
wrote:

Both my WALBRO pumps came with no replacement filters. A
large box in bold print in the instructions states the following:

" SERVICE DATA
The Walbro Marine Electronic Pump incorporates
two (2) built-in filters, one for filtering fine particles
and the other (a magnet) for trapping metalic
particles. Due to the construction of the protective
outer shell, these filters cannot be serviced."

The plastic outer shell appears to be glued together.
Perhaps this is a newer or different model than the
one you have.

Doug
s/v Callista

:
"Marc" wrote in message
...
The internal filter on the Walbro can be cleaned. In fact, they supply
a spare with the pump. Taking the pump apart is a little fussy in an
emergency situation. I am a little concerned to find out that a pump
failure may result in a blocked fuel supply due to the wobble plate.
Right now, I have the Walbro in line with my mechanical pump.


On Mon, 12 Apr 2004 17:55:34 -0400, "Doug Dotson"
wrote:

I seem to recall from the WALBRO docs that the pump is not
field servicable. Specifically, it states that the internal filters
cannot be changed.

Doug
s/v Callista

"Kelton Joyner" wrote in message
. ..
Unless you have isolation valves to allow servicing of a parallel
pump,
series works just as well for backup.
fuel wil flow through the unpowered pump.
Kelton
W4IND
s/v Isle Escape

Larry W4CSC wrote:
(Steven Shelikoff) wrote in
:


That begs the question why are you going to put two pumps in
parallel
if
you only want to run one at a time?

Steve



Backup?

Larry W4CSC

Parallelling fuel pumps
 

Why do you think Walbro is lying about this?

Doug
s/v Callista

"Marc" wrote in message
...
You got the same ones as we have,Doug. Yes, you have to bend the
mounting bracket drastically. Pry off the end caps and the clam shell
protection comes apart, exposing the pump. Remove three(?) screws on
the bottom plate to expose the filter.
http://www.autoperformanceengineerin...6000_pump.html


On Tue, 13 Apr 2004 11:48:16 -0400, "Doug Dotson"
wrote:

It appears these do not. Just to remove the mounting bracket
one would have to bend it out of shape quite drastically. I looked
closely at the brass caps top and bottom and it does appear that
they may be able to be pryed off. But in any case the instructions
say the filters are not servicable and there are no spares or
instructions for servicing provided.

Doug
s/v Callista

"Rich Hampel" wrote in message
...
Must be a 'new' version as all my Walbro pumps have
accessible/removalbe/cleanable protection screens/strainer wire.

In article , Doug Dotson
wrote:

Both my WALBRO pumps came with no replacement filters. A
large box in bold print in the instructions states the following:

" SERVICE DATA
The Walbro Marine Electronic Pump incorporates
two (2) built-in filters, one for filtering fine particles
and the other (a magnet) for trapping metalic
particles. Due to the construction of the protective
outer shell, these filters cannot be serviced."

The plastic outer shell appears to be glued together.
Perhaps this is a newer or different model than the
one you have.

Doug
s/v Callista

:
"Marc" wrote in message
...
The internal filter on the Walbro can be cleaned. In fact, they
supply
a spare with the pump. Taking the pump apart is a little fussy in
an
emergency situation. I am a little concerned to find out that a
pump
failure may result in a blocked fuel supply due to the wobble
plate.
Right now, I have the Walbro in line with my mechanical pump.


On Mon, 12 Apr 2004 17:55:34 -0400, "Doug Dotson"
wrote:

I seem to recall from the WALBRO docs that the pump is not
field servicable. Specifically, it states that the internal
filters
cannot be changed.

Doug
s/v Callista

"Kelton Joyner" wrote in message
. ..
Unless you have isolation valves to allow servicing of a
parallel
pump,
series works just as well for backup.
fuel wil flow through the unpowered pump.
Kelton
W4IND
s/v Isle Escape

Larry W4CSC wrote:
(Steven Shelikoff) wrote in
:


That begs the question why are you going to put two pumps in
parallel
if
you only want to run one at a time?

Steve



Backup?

Larry W4CSC

Parallelling fuel pumps
 

Why do you think Walbro is lying about this?

Doug
s/v Callista

"Marc" wrote in message
...
You got the same ones as we have,Doug. Yes, you have to bend the
mounting bracket drastically. Pry off the end caps and the clam shell
protection comes apart, exposing the pump. Remove three(?) screws on
the bottom plate to expose the filter.
http://www.autoperformanceengineerin...6000_pump.html


On Tue, 13 Apr 2004 11:48:16 -0400, "Doug Dotson"
wrote:

It appears these do not. Just to remove the mounting bracket
one would have to bend it out of shape quite drastically. I looked
closely at the brass caps top and bottom and it does appear that
they may be able to be pryed off. But in any case the instructions
say the filters are not servicable and there are no spares or
instructions for servicing provided.

Doug
s/v Callista

"Rich Hampel" wrote in message
...
Must be a 'new' version as all my Walbro pumps have
accessible/removalbe/cleanable protection screens/strainer wire.

In article , Doug Dotson
wrote:

Both my WALBRO pumps came with no replacement filters. A
large box in bold print in the instructions states the following:

" SERVICE DATA
The Walbro Marine Electronic Pump incorporates
two (2) built-in filters, one for filtering fine particles
and the other (a magnet) for trapping metalic
particles. Due to the construction of the protective
outer shell, these filters cannot be serviced."

The plastic outer shell appears to be glued together.
Perhaps this is a newer or different model than the
one you have.

Doug
s/v Callista

:
"Marc" wrote in message
...
The internal filter on the Walbro can be cleaned. In fact, they
supply
a spare with the pump. Taking the pump apart is a little fussy in
an
emergency situation. I am a little concerned to find out that a
pump
failure may result in a blocked fuel supply due to the wobble
plate.
Right now, I have the Walbro in line with my mechanical pump.


On Mon, 12 Apr 2004 17:55:34 -0400, "Doug Dotson"
wrote:

I seem to recall from the WALBRO docs that the pump is not
field servicable. Specifically, it states that the internal
filters
cannot be changed.

Doug
s/v Callista

"Kelton Joyner" wrote in message
. ..
Unless you have isolation valves to allow servicing of a
parallel
pump,
series works just as well for backup.
fuel wil flow through the unpowered pump.
Kelton
W4IND
s/v Isle Escape

Larry W4CSC wrote:
(Steven Shelikoff) wrote in
:


That begs the question why are you going to put two pumps in
parallel
if
you only want to run one at a time?

Steve



Backup?

Larry W4CSC

Parallelling fuel pumps
 

I think it has to do with the integrity of the protective shell and
corporate liability. I don't know why one is required. Obviously they
are the same pumps. Do you think it has something to do with mounting
the pump in the engine compartment.? CG Reg? Corrosion issues?. In any
event, my pump is located outside the engine compartment and I see no
reason not to remove the shell.

On Tue, 13 Apr 2004 12:18:06 -0400, "Doug Dotson"
wrote:

Why do you think Walbro is lying about this?

Doug
s/v Callista

"Marc" wrote in message
.. .
You got the same ones as we have,Doug. Yes, you have to bend the
mounting bracket drastically. Pry off the end caps and the clam shell
protection comes apart, exposing the pump. Remove three(?) screws on
the bottom plate to expose the filter.
http://www.autoperformanceengineerin...6000_pump.html


On Tue, 13 Apr 2004 11:48:16 -0400, "Doug Dotson"
wrote:

It appears these do not. Just to remove the mounting bracket
one would have to bend it out of shape quite drastically. I looked
closely at the brass caps top and bottom and it does appear that
they may be able to be pryed off. But in any case the instructions
say the filters are not servicable and there are no spares or
instructions for servicing provided.

Doug
s/v Callista

"Rich Hampel" wrote in message
...
Must be a 'new' version as all my Walbro pumps have
accessible/removalbe/cleanable protection screens/strainer wire.

In article , Doug Dotson
wrote:

Both my WALBRO pumps came with no replacement filters. A
large box in bold print in the instructions states the following:

" SERVICE DATA
The Walbro Marine Electronic Pump incorporates
two (2) built-in filters, one for filtering fine particles
and the other (a magnet) for trapping metalic
particles. Due to the construction of the protective
outer shell, these filters cannot be serviced."

The plastic outer shell appears to be glued together.
Perhaps this is a newer or different model than the
one you have.

Doug
s/v Callista

:
"Marc" wrote in message
...
The internal filter on the Walbro can be cleaned. In fact, they
supply
a spare with the pump. Taking the pump apart is a little fussy in
an
emergency situation. I am a little concerned to find out that a
pump
failure may result in a blocked fuel supply due to the wobble
plate.
Right now, I have the Walbro in line with my mechanical pump.


On Mon, 12 Apr 2004 17:55:34 -0400, "Doug Dotson"
wrote:

I seem to recall from the WALBRO docs that the pump is not
field servicable. Specifically, it states that the internal
filters
cannot be changed.

Doug
s/v Callista

"Kelton Joyner" wrote in message
. ..
Unless you have isolation valves to allow servicing of a
parallel
pump,
series works just as well for backup.
fuel wil flow through the unpowered pump.
Kelton
W4IND
s/v Isle Escape

Larry W4CSC wrote:
(Steven Shelikoff) wrote in
:


That begs the question why are you going to put two pumps in
parallel
if
you only want to run one at a time?

Steve



Backup?

Larry W4CSC

Parallelling fuel pumps
 

I think it has to do with the integrity of the protective shell and
corporate liability. I don't know why one is required. Obviously they
are the same pumps. Do you think it has something to do with mounting
the pump in the engine compartment.? CG Reg? Corrosion issues?. In any
event, my pump is located outside the engine compartment and I see no
reason not to remove the shell.

On Tue, 13 Apr 2004 12:18:06 -0400, "Doug Dotson"
wrote:

Why do you think Walbro is lying about this?

Doug
s/v Callista

"Marc" wrote in message
.. .
You got the same ones as we have,Doug. Yes, you have to bend the
mounting bracket drastically. Pry off the end caps and the clam shell
protection comes apart, exposing the pump. Remove three(?) screws on
the bottom plate to expose the filter.
http://www.autoperformanceengineerin...6000_pump.html


On Tue, 13 Apr 2004 11:48:16 -0400, "Doug Dotson"
wrote:

It appears these do not. Just to remove the mounting bracket
one would have to bend it out of shape quite drastically. I looked
closely at the brass caps top and bottom and it does appear that
they may be able to be pryed off. But in any case the instructions
say the filters are not servicable and there are no spares or
instructions for servicing provided.

Doug
s/v Callista

"Rich Hampel" wrote in message
...
Must be a 'new' version as all my Walbro pumps have
accessible/removalbe/cleanable protection screens/strainer wire.

In article , Doug Dotson
wrote:

Both my WALBRO pumps came with no replacement filters. A
large box in bold print in the instructions states the following:

" SERVICE DATA
The Walbro Marine Electronic Pump incorporates
two (2) built-in filters, one for filtering fine particles
and the other (a magnet) for trapping metalic
particles. Due to the construction of the protective
outer shell, these filters cannot be serviced."

The plastic outer shell appears to be glued together.
Perhaps this is a newer or different model than the
one you have.

Doug
s/v Callista

:
"Marc" wrote in message
...
The internal filter on the Walbro can be cleaned. In fact, they
supply
a spare with the pump. Taking the pump apart is a little fussy in
an
emergency situation. I am a little concerned to find out that a
pump
failure may result in a blocked fuel supply due to the wobble
plate.
Right now, I have the Walbro in line with my mechanical pump.


On Mon, 12 Apr 2004 17:55:34 -0400, "Doug Dotson"
wrote:

I seem to recall from the WALBRO docs that the pump is not
field servicable. Specifically, it states that the internal
filters
cannot be changed.

Doug
s/v Callista

"Kelton Joyner" wrote in message
. ..
Unless you have isolation valves to allow servicing of a
parallel
pump,
series works just as well for backup.
fuel wil flow through the unpowered pump.
Kelton
W4IND
s/v Isle Escape

Larry W4CSC wrote:
(Steven Shelikoff) wrote in
:


That begs the question why are you going to put two pumps in
parallel
if
you only want to run one at a time?

Steve



Backup?

Larry W4CSC

Parallelling fuel pumps
 

"Doug Dotson" wrote in
:

Glenn,

That is pretty much what I was figuring on other than the
check valves. Not sure I want a center off switch though.
I would prefer that one or the other be on at all times. I'm
also considering putting an hours-meter on each so that I
can balance the use.

Doug
s/v Callista


I'll also vote for a manual valve on both in parallel......

We're in a seaway, big waves. The pump goes into failure mode, we switch
on the backup and are back in business. Wouldn't it be good if we could
isolate the failed pump for repairs, remove/replace or tear it down for
that new diaphram while the other pump has the load and the first mate or
autopilot is driving? Sure would be nice to be able to get that failed
pump offline while the boat's still underway for repairs. Can't do that on
the series pumps without some crazy plumbing bypasses and lots of
valves....

Larry W4CSC