Racor gauge education?

[koliver]

All of this discussion of the water block treatment of the Racor filters presumes there will be some water in the fuel.
After 42 years, I had the dubious privilege of seeing the inside of my fuel tank last year at this time. There was no evidence whatsoever that there had been any water in that tank. Ever.
I have had the boat 28 years. The Racor bowls have yielded no evidence of water in the fuel in that time.
Nick, I suspect you buy your fuel in the same places as I do.
I wouldn't worry about the water blocking treatment degrading in your spare Racor.

 

[ranger58sb]

I don't remember ever seeing water when draining from our Racors, either.

Maybe the "change one every other year" could be easily modified to "if you've ever seen any actual water in drainage out of that one..." or some such.

-Chris

 

[O C Diver]

I've probably had bad a small amount of bad fuel and water almost every year since 2016. Now to be fair, the water has never been more than 3 ounces and the crud was an ounce or two in the bowl or on the filter. While it's disappointing, the filters on the engine would have easily handled it.

I suck from the absolute bottom of the tank and the impurities almost always end up in the fuel polisher. But still, marine fuel just doesn't seem to be as clean as over the road. For perspective, my fuel consumption is between 1,200 and 2,000 gallons per year.

Ted

 

[catalinajack]

I've probably had bad a small amount of bad fuel and water almost every year since 2016. Now to be fair, the water has never been more than 3 ounces and the crud was an ounce or two in the bowl or on the filter. While it's disappointing, the filters on the engine would have easily handled it.



I suck from the absolute bottom of the tank and the impurities almost always end up in the fuel polisher. But still, marine fuel just doesn't seem to be as clean as over the road. For perspective, my fuel consumption is between 1,200 and 2,000 gallons per year.



Ted

That's a lot of fuel and a very, VERY small amount of water and crud relative the number of gallons. That argues for even marine fuel being very clean these days. It also obviates the need for fuel polishing although doing so does no harm. Having bottom feeding fuel tanks is an important factor. My boat is a bottom feeder. Occasionally, I open the drain/test valve at the very bottom of the tanks. In eight years, I have NEVER drained off any water and just a few flecks of crud. Any water, to the small extent there may be, in the tanks (and crud and unseen particulates) gets continually drawn through the filters.

 

[O C Diver]

That's a lot of fuel and a very, VERY small amount of water and crud relative the number of gallons. That argues for even marine fuel being very clean these days. It also obviates the need for fuel polishing although doing so does no harm. Having bottom feeding fuel tanks is an important factor. My boat is a bottom feeder. Occasionally, I open the drain/test valve at the very bottom of the tanks. In eight years, I have NEVER drained off any water and just a few flecks of crud. Any water, to the small extent there may be, in the tanks (and crud and unseen particulates) gets continually drawn through the filters.

I use to average 30,000 miles (1,200 +/- gallons) a year in my diesel pickup. Never saw anything like that amount of water or crud in the filter separator.

The reason it runs through the polisher / transfer pump is that I fill the port tank, polish, transfer and consume from the starboard tank. It keeps the boat balanced port to starboard, and insures that the engine and generator get clean fuel.

Ted

 

[Juliet 15]

Applicable question to the topic, but slightly different. What are the small blue platic up-or-down "valves" (?) found at the top of the Racor gouges? You can pull them up or leave them flush. There appears to be no difference in operation...

 

[Circumnavigator]

I agree that in boats where the filters are difficult to check underway that it would be better to have a gauge with followers -- or, Maretron makes a pressure/vacuum sensor that puts the status on the NEMA 2000 bus, so you can look at underway. Recommended.



Whether you ever see pressure on the gauge depends entirely on the location of the tank feeding it. Fintry's day tank is one deck up, so with a clean filter, we see around +5 PSI. On Morning Light the middle of the day tank is at the same height as the gauge so it goes from pressure to vacuum with a clean filter. This will be true with many installations.


Your engine manual may tell you how much of a vacuum is OK.


Jim

 

[genedanko]

Get the Racor Gauge with a drag needle

Diesel fuel supplies run under vacuum between the tank (atmosphere) and the lift pump.

0-3" Hg is the normal operating zone for a clean filter.
At 7" Hg, replace the filter.
At around 10" Hg most diesels will shut down.
At around 15" Hg diesel fuel will start to boil.

The dark red drag needle is useful. it can be set to ride on the black needle (instantaneous conditions) and will stay at the worst case encountered on your run. This gives you an indication of how the system is performing at speed while you are at the helm.

There is also a bright red needle that the operator can set as a "do not exceed" reminder.

The gauge shown in the original post seems to show both positive and negative pressure; not really useful in most instances.

 

[Steve DAntonio]

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/
View attachment 132302

And I'll reiterate, the Dent gauge is far superior to the Racor standard or pressure/vacuum gauge, the latter makes no sense what so ever in these applications. You might find this article helpful as well https://stevedmarineconsulting.com/the-invaluable-vacuum-gauge-editorial-my-kingdom-for-a-set-screw/

 

[Steve DAntonio]

Applicable question to the topic, but slightly different. What are the small blue platic up-or-down "valves" (?) found at the top of the Racor gouges? You can pull them up or leave them flush. There appears to be no difference in operation...

Used to equalize pressure within the gauge with atmospheric pressure, some use a yellow lever style valve too. Generally, you can leave these open if the gauge is installed vertically, otherwise you need to cycle the valve every them you read the gauge.

 

[ranger58sb]

And I'll reiterate, the Dent gauge is far superior to the Racor standard or pressure/vacuum gauge...

On my list. Thanks for emphasis.

-Chris

 

[SuzieWong]

Failure of vacuum gauges?

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.View attachment 132301

I have two SBMAR double filtration systems for the engine fuel system. Appears both system have failed:
- System A shows high negative pressure despite system depressurized, aired, filters removed and valves wide open
- System B shows no negative pressure in fuel supply line despite engine starving of fuel. Bypassing the fuel filters and the engine runs fine.

This makes me wonder how reliable SBMAR suction indicators are.
Can anyone else report failures on these?
Indicators had been lying around in hot and humid conditions for years... due to shipyard's neglect. Could that cause failure of these (not cheap) indicators?

 

[Pete Meisinger]

No wonder many boaters drink. If I had gauges like that on my boat I would drink also.

pete

 

[catalinajack]

I have two SBMAR double filtration systems for the engine fuel system. Appears both system have failed:
- System A shows high negative pressure despite system depressurized, aired, filters removed and valves wide open
- System B shows no negative pressure in fuel supply line despite engine starving of fuel. Bypassing the fuel filters and the engine runs fine.

This makes me wonder how reliable SBMAR suction indicators are.
Can anyone else report failures on these?
Indicators had been lying around in hot and humid conditions for years... due to shipyard's neglect. Could that cause failure of these (not cheap) indicators?

Do you really think Tony Athens sells junk? Or Racor? Look vor other causes of you failures.

 

[catalinajack]

No wonder many boaters drink. If I had gauges like that on my boat I would drink also.



pete

Are you referring to my gauges? If so, what are you talking about?

 

[catalinajack]

I have two SBMAR double filtration systems for the engine fuel system. Appears both system have failed:
- System A shows high negative pressure despite system depressurized, aired, filters removed and valves wide open
- System B shows no negative pressure in fuel supply line despite engine starving of fuel. Bypassing the fuel filters and the engine runs fine.

This makes me wonder how reliable SBMAR suction indicators are.
Can anyone else report failures on these?
Indicators had been lying around in hot and humid conditions for years... due to shipyard's neglect. Could that cause failure of these (not cheap) indicators?

Thinking about it some more, the gauges, even if they failed, would have nothing to do with the efficacy of the fuel supply. You have bypassed the fuel filters and the engines run fine. Have you installed new fuel filters? Are your fuel lines collapsing internally, unseen? What you have there is a simple fuel filter head. They don't "fail". Something else is at work, IMHO.

 

[SuzieWong]

Question why suction gauges do not work

I want to make clear: I do not think SBMAR sells junk. I bought and had installed them in first place and will keep the double filtration system.
Yes, I can get the engines up and running by simply replacing the fuel filters with new units.
The reason why I am asking is that I want to ensure proper indication of new gauges which I plan to order. For me it is imperative to have suction gauges at the fuel filters. A: to avoid unnecessary changes, B: (and more importantly): to avoid engine shutdown due to fuel starvation.
Question remains: why does my boat suffer such a high failure rate of vacuum gauges? Could it be improper handling at the shipyard which had stowed them in humid conditions for years before installing them? Narrowing down on the cause of failure is the first step in preventing a re-occurrence!

 

[CharlieO.]

I would not be looking to blame the shipyard for "humid" storage. I have yet to find any mechanical contraptions on my boat that failed due to humidity. Not saying it doesn't happen, but.... Go buy some cheapos and install to verify the inaccuracy of your sbmar's. Are they able to be calibrated?

 

[catalinajack]

I want to make clear: I do not think SBMAR sells junk. I bought and had installed them in first place and will keep the double filtration system.

Yes, I can get the engines up and running by simply replacing the fuel filters with new units.

The reason why I am asking is that I want to ensure proper indication of new gauges which I plan to order. For me it is imperative to have suction gauges at the fuel filters. A: to avoid unnecessary changes, B: (and more importantly): to avoid engine shutdown due to fuel starvation.

Question remains: why does my boat suffer such a high failure rate of vacuum gauges? Could it be improper handling at the shipyard which had stowed them in humid conditions for years before installing them? Narrowing down on the cause of failure is the first step in preventing a re-occurrence!

When saying SBMAR does not sell junk, I meant to suggest it was not the guage that is the problem.

 

[Bmarler]

I want to make clear: I do not think SBMAR sells junk. I bought and had installed them in first place and will keep the double filtration system.
Yes, I can get the engines up and running by simply replacing the fuel filters with new units.
The reason why I am asking is that I want to ensure proper indication of new gauges which I plan to order. For me it is imperative to have suction gauges at the fuel filters. A: to avoid unnecessary changes, B: (and more importantly): to avoid engine shutdown due to fuel starvation.
Question remains: why does my boat suffer such a high failure rate of vacuum gauges? Could it be improper handling at the shipyard which had stowed them in humid conditions for years before installing them? Narrowing down on the cause of failure is the first step in preventing a re-occurrence!

In order to figure out what caused the failure, you need to strip down the assemblies and look closely at them. Look for blockages, debris, etc… the gauge ports are pretty small orifices, and can be clogged if debris gets in. Strip them, clean them, blow compressed air through all the passages. If the gauges are removed from the manifold do they zero out ok? If so the problem is blockage somewhere. If they don’t zero out, they are bad. I would mount all the gauges together on a temporary manifold along with a known good gauge and test them all together so you are sure they read correctly.

 

[Nick F]

Please post the results of any discoveries about why the gage is not working - thats how we all learn!

 

[twistedtree]

Where/how is the filter and gauge assembly mounted? Is in mounted to the hull/stringers, or to the engine itself? I ask because gauges take a real thrashing when subject to vibration, and I wonder if somehow that's what's breaking yours. Are glycerin filled?

 

[RickyD]

My first trawler had vacuum gauges mounted in the fly bridge from where the boat is generally operated. That was good. Accuracy of the measurement is not important only the variation from clean to clogged.

For my current ride, I use and am very happy with the Racor three needle
t-handle gauges. After a run, a quick look and I have verified that my filters are still good. Also, with my installation, I start out with some vacuum. Again, its the relative measurement that is important. I have not clogged a filter since I put them in so I may try the valve restriction method to see where It get critical.

 

[RT Firefly]

Greetings,
Not going to read through the whole thread and it may have been mentioned but I used to have to "burp" my glycerine filled Racor gauges occasionally.
The gauges read some vacuum even when the engine was off. I would carefully lift an edge of the rubber plug at the top of the gauge and allow air into the gauge body. The needle would drop to 0.

 

[Steve DAntonio]

Even "dry" gauges need to be equalized from time to time.