Racor gauge education?

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ranger58sb

ranger58sb

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58' Sedan Bridge
Can ya'll help me learn how to interpret our Racor vacuum gauges? We've not had one before, and I haven't found instructions on the Parker-Hannefin website...

The gauge (RK19667) presents:
- 0-30 "Hg to the left (outside, black typeface)
- 0-100 kPa to the left (inside, blue typeface)
- 1-15 psi to the right (outside, black typeface)
- 0-100 kPa to the right (inside, blue typface)

And there's a black area at 12 o'clock which encompasses approx 0-3 "Hg/0-10 kPa) to the left and approx 0-2 psi/0-10 kPa to the right.

The needle on one of our 751000MAX pairs in the black area, just a hair left of zero. The other is outside the black to the right and reading approx 3 psi/15 kPa.

I think I know that "Hg (presumably inches of Mercury) is inches of vacuum. (Yes?)

And that inches of vacuum is what tells me when to change the filters. (Yes?)

Neither of our needles are swinging to the left (11 o'clock direction) of center (zero). So does that mean neither gauge is telling me to immediately change the filter?

Or...?

Is a positive kPa/psi reading -- outside the black area -- good? Or bad?

I can't tell what's supposed to happen when I change the selector on one pair from one filter to the other. I did make that change yesterday, to see what happens, but near as I can tell, squat happened. IOW, no change in needle position on that pair. The gauges don't appear to have any user-selectable "reset" capability. And these gauges don't have a "follower and change indicator"...

Help?

-Chris
 

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ranger58sb said:
Can ya'll help me learn how to interpret our Racor vacuum gauges? We've not had one before, and I haven't found instructions on the Parker-Hannefin website...



The gauge (RK19667) presents:

- 0-30 "Hg to the left (outside, black typeface)

- 0-100 kPa to the left (inside, blue typeface)

- 1-15 psi to the right (outside, black typeface)

- 0-100 kPa to the right (inside, blue typface)



And there's a black area at 12 o'clock which encompasses approx 0-3 "Hg/0-10 kPa) to the left and approx 0-2 psi/0-10 kPa to the right.



The needle on one of our 751000MAX pairs in the black area, just a hair left of zero. The other is outside the black to the right and reading approx 3 psi/15 kPa.



I think I know that "Hg (presumably inches of Mercury) is inches of vacuum. (Yes?)



And that inches of vacuum is what tells me when to change the filters. (Yes?)



Neither of our needles are swinging to the left (11 o'clock direction) of center (zero). So does that mean neither gauge is telling me to immediately change the filter?



Or...?



Is a positive kPa/psi reading -- outside the black area -- good? Or bad?



I can't tell what's supposed to happen when I change the selector on one pair from one filter to the other. I did make that change yesterday, to see what happens, but near as I can tell, squat happened. IOW, no change in needle position on that pair. The gauges don't appear to have any user-selectable "reset" capability. And these gauges don't have a "follower and change indicator"...



Help?



-Chris
Click to expand...
Ditch the Racor gauge and get these from Tony Athens (sbmar.com). When the drag needle nears the "red zone", it's time to chage the filter. The black drag needle is difficult to see in the picture but, in use, it stays in place even after a vacuum dissipates thus giving you a constant indicator of the filter's health. Replacing filters on a time basis becomes totally unecessary saving time and expense.Trawler%20Forum2095747527.jpg
 
Chris - I can't help you with interpreting your gauge except to speculate its both a pressure gauge (left side) and a vacuum gauge. I have a standard Racor vacuum gauge which which has G/Y/R zone and a drag needle. But measures all the way to 30hg which is unnecessary - analogous to putting a 200 mph speedo in a Buick LeSabre,

From a past thread, Steve D chimed in with this Dent Gauge that is calibrated to just 15 hg would be much better. Unfortunately, the $145 price tag keeps me a looker instead of a buyer. But if I had your setup, I might be persuaded.

https://dentmarine.com/
391706948.jpg
 
ranger58sb said:
Can ya'll help me learn how to interpret our Racor vacuum gauges? We've not had one before, and I haven't found instructions on the Parker-Hannefin website...

The gauge (RK19667) presents:
- 0-30 "Hg to the left (outside, black typeface)
- 0-100 kPa to the left (inside, blue typeface)
- 1-15 psi to the right (outside, black typeface)
- 0-100 kPa to the right (inside, blue typface)

And there's a black area at 12 o'clock which encompasses approx 0-3 "Hg/0-10 kPa) to the left and approx 0-2 psi/0-10 kPa to the right.
MEANS THERE IS VIRTUALLY NO PRESSURE OR VACUUM. THIS WOULD BE NORMAL WHEN THE ENGINE IS NOT OPERATING.

The needle on one of our 751000MAX pairs in the black area, just a hair left of zero. The other is outside the black to the right and reading approx 3 psi/15 kPa. LIKELY NORMAL GUAGE INACCURACY OR MAYBE SOME SLIGHT DAMAGE FROM YEARS OF USE.

I think I know that "Hg (presumably inches of Mercury) is inches of vacuum. (Yes?)
YES

And that inches of vacuum is what tells me when to change the filters. (Yes?)
YES

Neither of our needles are swinging to the left (11 o'clock direction) of center (zero). So does that mean neither gauge is telling me to immediately change the filter?
YES. MEANS THERE IS NO RESISTRICTION OR FOULING OF THE FILTERS

Or...?

Is a positive kPa/psi reading -- outside the black area -- good? Or bad?

SHOULD NOT SEE THAT IF THIS IS USED IN YOUR FUEL SUPPLY SYSTEM AFTER THE FILTERS UNLESS THE TANK VENT HOSE IS PLUGGED AND THE PRESSURE BUILDS FROM AMBIENT TEMPERATURE BUILDUP WARMING THE TANK AND FUEL. NOT TERRIBLY LIKELY.

DEPENDS UPON THE USE THE GUAGE IS PUT TO. FOR FILTER RESTRICTION YOU WOULD/SHOULD ONLY SEE VACUUM.
GENERALLY A MAX. VAC. FOR A FUEL FILTER WOULD BE 10" MERCURY. SOME ENGINES REQUIRE FILTER CHANGES AT 8" VAC. YOU WILL HAVE TO LEARN THAT FOR YOUR ENGINE.

I can't tell what's supposed to happen when I change the selector on one pair from one filter to the other. I did make that change yesterday, to see what happens, but near as I can tell, squat happened. IOW, no change in needle position on that pair. The gauges don't appear to have any user-selectable "reset" capability. And these gauges don't have a "follower and change indicator"...
NO CHANGE WHEN THE VALVE IS FLIPPED MEANS NO FILTER RESTRICTION SO GOOD.

Help?

-Chris
Click to expand...



I ALSO AGREE THAT YOU SHOULD GET RID OF THOSE GUAGES AND REPLACE THEM WITH UNITS FROM SEABOARD MARINE OR DESIGNATED ENGINEER OR DENT MARINE.
BOTH SELL GOOD QUALITY GUAGES WITH A TELLTALE NEEDLE THAT STAYS AT THE HIGHEST LEVEL REACHED UNTILL YOU RESET THEM. MEANS YOU CAN CHECK THEM AFTER A RUN , NOT DURING A RUN.

HOPE THIS HELPS.
i ALSO APOLOGIZE FOR THE CAPS AS i STILL CANNOT FIGURE OUT HOW TO USE THE COLOURS OF PRINT FOR ANSWERS AS A HIGHLIGHT.
 
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Well, I understand colors can be helpful, and I see Racor has a color/telltale equivalent to the Seaboard the Dent vacuum-only gauges (RK 19668, $135)...

But just now I'm not thrilled about spending $$$ to replace what are probably OK gauges... just to get some colors and a follower... assuming ours are actually working... and assuming I can get the Rosetta Stone, and hints on how to read the rascals. :)

That said, I may have twigged onto something. The 751000MAX filter pairs we have, and other similar Racors, can be mounted either on the suction side or on the pressure side of a fuel installation. I'm beginning to think the gauges we have are therefore dual-purpose (as Peter suggested), and therefore meant to be useful in either installation type.

If so, that would mean I just work out which type ours is -- suction or pressure -- and then pay attention to either the vacuum measurements (left side of clockface) or the pressure measurements, depending.

I've not ever seen a pressure-side installation before (that I know of)... but the filter installation diagram hints in that case the tanks would be higher than the filters... and ours aren't.

If ours is a suction installation, presumably vacuum readings would be applicable. In a suction installation, I don't yet see how we'd get a positive pressure (PSI) reading in the gauge on one pair, though.

And then... I've only checked our gauges while at the dock, engines off... and that's definitely where a follower/drag needle would be useful. I'll have to do a "live" check to see whether the readings I've seen so far are even indicative of anything whatsoever. And that in turn may very well alter my original thoughts about replacing working stuff, so thanks to all for that!

-Chris
 
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I put the Racor T handle gauges on our last boat. Don’t need a wrench to change the filter.

Racor RK 19671 RK19671 T-Handle Vac Gauge
 
To the OP:
InHg side is vacuum.
PSIG side is positive pressure.
If the gauge is reading 3 psi when is open to atmosphere (like when the filter top is removed), then the gauge has been damaged. It is possible to be reading positive without the engine running due to trapped pressure due to closed off valves and the fluid heats up. OR a standing height of fuel above the gauge. 3 psig is about 8 FEET of standing fuel oil, not likely!!!
 
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OK - here we go. It is possible to stay with the gages you have, but they are far from user friendly. They don't have coloured zones and they don't have a drag needle, so you have to read them while under way. Furthermore, the interesting scale of vacuum is only half of the gage and so you have to watch for smaller movements of the needle - a quick glance will not suffice.

The gages you have are "compound" gages, meaning that they can measure both positive pressure and vacuum. The zero is with the needle upright (12 o´clock).

The black zone is to indicate that, due to inaccuracy, the needle might not point exactly at 12 o´clock when there is zero pressure/vacuum - with the manufacturing variations it could be anywhere on the black zone (its obviously not a precision gage!).

The gage reads vacuum on the left side (0 to 30 inches of mercury (inHg), which is the same as 0 - 15 psi of vacuum) and positive pressure (0 to 15 psi) on the right side.

The coloured gages shown above by others suggest a "yellow" zone starting at around 5 (or 6) inHg and "red" zone starting at 10 inHg. So on your gages the yellow will start at black number 5 (or 6) on the left hand scale (around 11 o´clock) and the red will start at 10 on the same scale.

Regards,
Nick
 
Last edited:
Chris
This thread strikes me as a solution seeking a problem.
In this modern age, where fuel is ULSD almost everywhere, unless you are getting ready for a season in some exotic place where their fuel is filthy or full of water, your filters are not getting a workout and a setup such as discussed here is not going to be of any use to you whatsoever.
When I started trawlering, in 1994, the best fuel I could buy here in SW BC was still full of crud, so filters needed to be changed twice a year, or in some cases, much more often than that. Over the next decades, the EPA in the US has mandated a reduction in Sulphur content, first to LSD, then to ULSD, so that now there is very little Sulphur going into our atmosphere and contributing to Global Warming. Those standards have trickled across the border so you can consider them applicable to Canada as well. In order to reduce Sulphur to present day requirements, the fuel has become remarkably clean. This has manifested in the filter changing intervals stretching out. In my case, I have gone from twice annual to every four years. I like being able to see through the clear plastic bowls on my filters, Racor 500s, that are prominently located on the rear wall of my ER, between engines. This month, among other things, I changed filters, not because I saw crud in the bowls, but because I checked my log and found that the last change was in August of 2018. I also check for the time before that, which was in 2014.
 
OK, all... the light is dawning. Assuming we have a suction operation -- a vacuum measurement is germane.
The colors still don't impress me overly much, but I see now a drag needle/follower is better than what I have... and what I have is only telling me something while the engines are running... probably at various RPM. So the "at rest" readings I've seen are essentially useless.

And now I know why. :)


High Wire said:
It is possible to be reading positive without the engine running due to trapped pressure due to closed off valves and the fluid heats up.
Click to expand...

Ah!


Nick F said:
OK - here we go. It is possible to stay with the gages you have, but they are far from user friendly. They don't have coloured zones and they don't have a drag needle, so you have to read them while under way. Furthermore, the interesting scale of vacuum is only half of the gage and so you have to watch for smaller movements of the needle - a quick glance will not suffice.

The gages you have are "compound" gages, meaning that they can measure both positive pressure and vacuum. The zero is with the needle upright (12 o´clock).

The black zone is to indicate that, due to inaccuracy, the needle might not point exactly at 12 o´clock when there is zero pressure/vacuum - with the manufacturing variations it could be anywhere on the black zone (its obviously not a precision gage!).
Click to expand...

Thanks, very useful explanation.


koliver said:
Chris
This thread strikes me as a solution seeking a problem.
In this modern age, where fuel is ULSD almost everywhere, unless you are getting ready for a season in some exotic place where their fuel is filthy or full of water, your filters are not getting a workout and a setup such as discussed here is not going to be of any use to you whatsoever.
Click to expand...

I get your point. :)

But I'm also still baselining maintenance on this boat -- even after a year+ of ownership <sigh> -- and I'd feel better if I had a clue about the age/condition of the current filters. And I'd even just as soon start with new filters when I get time to address the Racors. My questions are preparatory to a complete drain/clean/filter change and I already know I want to install the brass drain plugs. Now I reckon I might as well change the gauges at the same time, while the system is open... even though (as you note) fuel is usually clean and filters are usually undertaxed.

-Chris
 
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Anyone have a theory why the pic in OP (#1) shows positive pressure of around 3 psi? Maybe filter is mounted low, tanks are full which creates back-pressure? Alternative is the gauge is malfunctioning.

Chris - the gauge is legible, but I guess you could put a yellow dot at 5 hg; and a red dot at 10 hg so you don't have to remember. Still need to check underway at normal cruising speed.

Peter
 
I am in agreement with replacing the gauges with ones with followers, checking the gauges while under full power is at the least inconvenient if not dangerous depending on where you have them mounted. Rather than changing my filters based on hours I change based on filter restriction, love the follower needle!
 
Cigatoo said:
If you are going to upgrade your vacuum gauge why not take this route? Nice to have the gauge on the instrument panel. After reading completely the max hose length is 15 feet. That might limit the possibilities.

https://www.defender.com/product.jsp?id=3939836
Click to expand...
I have both those and tell tails on my Racors. In an OCD sort of way, it's nice to be able to glance at the vacuum gauge as weather conditions go fubar to know that the fuel filtration system is still ok.

Ted
 
It could be that it is time for old school dial gauges to be replaced with something more accurate and easier to read. As noted above, a gauge that goes to -30 inHg isn't required (unless you want to suck stuff through your filters). And $145 seems silly even for a "marine" vacuum gauge (when compared to its $15 non-marine brethren). While a drag needle might be more convenient, there is plenty of interweb talk about how the drag needle adversely effects accuracy at lower vacuum, just where boaters are interested in accuracy.

How about something that can be read from outside the engine room? How about increased accuracy so that one could read -1.24 inHg last week and -1.68 inHG after 10 hours cruising? Maybe something that records the maximum vacuum? How about for >$40 (including shipping)?

https://www.amazon.com/Digital-Mano...Q==&sprefix=digital+manometer,aps,212&sr=8-23
 
Marco Flamingo said:
It could be that it is time for old school dial gauges to be replaced with something more accurate and easier to read. As noted above, a gauge that goes to -30 inHg isn't required (unless you want to suck stuff through your filters). And $145 seems silly even for a "marine" vacuum gauge (when compared to its $15 non-marine brethren). While a drag needle might be more convenient, there is plenty of interweb talk about how the drag needle adversely effects accuracy at lower vacuum, just where boaters are interested in accuracy.

How about something that can be read from outside the engine room? How about increased accuracy so that one could read -1.24 inHg last week and -1.68 inHG after 10 hours cruising? Maybe something that records the maximum vacuum? How about for >$40 (including shipping)?

https://www.amazon.com/Digital-Mano...Q==&sprefix=digital+manometer,aps,212&sr=8-23
Click to expand...

My only criticism without seeing the gauge in-person, is how good is the component quality. Remember that a failure of any part in vacuum, means that the engine quits from air in the fuel system. Most mechanical vacuum gauges don't fail, allowing air into the system, they read inaccurately.

Ted
 
I have the "vertical" T-handle Racor gauges.
300782.jpg

Easy to install, they hold their settings until you reset them (similar to the drag needle on the dial gauges) and they have the red-yellow-green indication.


Knowing the state of your filtration at a glance is important.
 
koliver said:
Chris

This thread strikes me as a solution seeking a problem.

In this modern age, where fuel is ULSD almost everywhere, unless you are getting ready for a season in some exotic place where their fuel is filthy or full of water, your filters are not getting a workout and a setup such as discussed here is not going to be of any use to you whatsoever.

When I started trawlering, in 1994, the best fuel I could buy here in SW BC was still full of crud, so filters needed to be changed twice a year, or in some cases, much more often than that. Over the next decades, the EPA in the US has mandated a reduction in Sulphur content, first to LSD, then to ULSD, so that now there is very little Sulphur going into our atmosphere and contributing to Global Warming. Those standards have trickled across the border so you can consider them applicable to Canada as well. In order to reduce Sulphur to present day requirements, the fuel has become remarkably clean. This has manifested in the filter changing intervals stretching out. In my case, I have gone from twice annual to every four years. I like being able to see through the clear plastic bowls on my filters, Racor 500s, that are prominently located on the rear wall of my ER, between engines. This month, among other things, I changed filters, not because I saw crud in the bowls, but because I checked my log and found that the last change was in August of 2018. I also check for the time before that, which was in 2014.
Click to expand...
Changing filters on a time basis is just a guess often leading to premature changes. With a vacuum gauge, filters are changed only when indicated.
 
CaptTom said:
I have the "vertical" T-handle Racor gauges.
300782.jpg

Easy to install, they hold their settings until you reset them (similar to the drag needle on the dial gauges) and they have the red-yellow-green indication.


Knowing the state of your filtration at a glance is important.
Click to expand...

That was my choice too, both mains and generator. Easy to read and reset.:thumb:
 
koliver said:
. This has manifested in the filter changing intervals stretching out. In my case, I have gone from twice annual to every four years. I like being able to see through the clear plastic bowls on my filters, Racor 500s, that are prominently located on the rear wall of my ER, between engines. This month, among other things, I changed filters, not because I saw crud in the bowls, but because I checked my log and found that the last change was in August of 2018. I also check for the time before that, which was in 2014.
Click to expand...


Yep, that's pretty much us as well on the 1000's
Bought a box full of filters when we got her expecting to be going through them.
Looking to be a lifetime supply
 
If you have already invested in a boat monitoring system, there are commercial grade sensors for fuel pressure/vacuum, and display capabilities from remote devices. I have done this with Maretron, but other's can do it too, I'm sure. It's handy to be able to monitor from the helm or flybridge while underway, and set alarms to warn you early of potential problems. The sensors are around $200, plus the cost of a port on an FPM100 for the maretron system, so all-in probably 2x the cost of a good dial gauge, but more functional as well. Your choice whether it's worth it to you.
 
I really do appreciate all the commentary, along with the pointer to the older thread; thanks all!

And I remembered I could check notes from our May/June '21 engine rehab work. Turns out sure enough the guys replaced all of our Racor filters then... so in the grand scheme of things, I can very probably change gauges and add the brass drain plugs when I can get a round tuit.

-Chris
 
Filters are cheap, engines aren’t.

I have a nice vacuum gauge with a tell tale that works well. I also have Dual Racor filters. I run using one filter, leaving the other as a backup. I replace the filter that I have been using yearly and then switch to the filter that has been sitting on standby for a year.

Since my vacuum gauge has never shown over 5inHg this means I am changing the filter much more often than “necessary”. OTOH, Parker has said that their water-block feature of their filters degrades over time while sitting in diesel fuel. So as long as I’m physically able to easily change one filter yearly, I’ll keep doing it.

Filters are cheap, engines aren’t.
 
dhays said:
Since my vacuum gauge has never shown over 5inHg this means I am changing the filter much more often than “necessary”. OTOH, Parker has said that their water-block feature of their filters degrades over time while sitting in diesel fuel.
Click to expand...


That's my understanding too. Over time the water repellent degrades.


I'm with Dave on this. Filters are cheap and an annual change prevents issues while underway. I always try to do maintenance on MY schedule, not because of failures. That's why they call it maintenance.
 
dhays said:
Filters are cheap, engines aren’t.

I have a nice vacuum gauge with a tell tale that works well. I also have Dual Racor filters. I run using one filter, leaving the other as a backup. I replace the filter that I have been using yearly and then switch to the filter that has been sitting on standby for a year.

Since my vacuum gauge has never shown over 5inHg this means I am changing the filter much more often than “necessary”. OTOH, Parker has said that their water-block feature of their filters degrades over time while sitting in diesel fuel. So as long as I’m physically able to easily change one filter yearly, I’ll keep doing it.

Filters are cheap, engines aren’t.
Click to expand...

We always had independent water separators.
 
Interesting question:

I have dual Racors. Both Racors have a filter element in them and are full of diesel. Only one Racor is in use (for years). Is the water block feature of the filter element in the standby Racor degrading with time?

Should I consider keeping the standby Racor dry??

Curious . . .
Nick
 
Nick F said:
Interesting question:

I have dual Racors. Both Racors have a filter element in them and are full of diesel. Only one Racor is in use (for years). Is the water block feature of the filter element in the standby Racor degrading with time?

Should I consider keeping the standby Racor dry??
Nick
Click to expand...

According to Racor the Standby filter's water block ability IS degrading with time. That is why I change out the filter that has been in use for the year, and then make the standby filter the new active filter. The new filter now becomes the standby filter.

So while the active filter has "aged" for a year in fuel, I think it is a good system for me. I would not let the standby filter sit for years on end. I don't think that it is worth keeping the standby filter dry. You want to be able to switch to the standby filter with no interruption in operation. You don't want to be trying to bleed the system in the process.
 
Am I missing something here?
I thought the 1000 and 500 series were a centrifuge and spun water out to the bowl anyway?
So what does the waterbloc in the filter do again?
 
Simi 60 said:
Am I missing something here?
I thought the 1000 and 500 series were a centrifuge and spun water out to the bowl anyway?
So what does the waterbloc in the filter do again?
Click to expand...

The centerfusial effect requires a significant flow that may not occur at idle. Also micro water droplets may cling to other less heavy contaminants and be sucked up to the filter element.

The waterbloc coating is designed to prevent the small droplets from going through the filter element.

Ted
 
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