As the world goes away from monitors, the trend is to go back to filter separators. To do so, there should and/or must be a sump water sensor to EI-1596, the EI standard for filter vessels and accessories.

Please also review the EI-1550 and EI-1530. These documents better and more completely explain how and why we all do what we do in fuel filtration, water handling and system design. They are a very important foundation for fuel handling and should be on every bookshelf.

Long, long ago the industry went to filter monitors, in part because we were concerned that sometimes the filter separators of that time failed occasionally (Monitors were also less expensive and lighter). But the EI and the filter manufacturers have dramatically improved filter separators and the risks are virtually gone, as long as the water control can be relied on. That means the water sensor must be properly made and regularly tested. That means that it meets the requirements of the EI-1596, which was designed to ensure this.

How can we be sure of filter separators? The simple answer is that we already know for sure. At two major international airports, which get fuel from multi-product pipelines, they have been operating for over 25 years with filter separators followed by monitors on every refueler and hydrant cart. They have followed the EI/API standards always in this regard. Not once have they had to replace a monitor element due to high differential pressure, proving no water ever got through their filter separators. Modern filter separators made to meet EI-1581 really are very, very good at removing water from jet fuel! But if water is present, the QC operator MUST know this. It had to come from somewhere and your #1 job in quality control is looking for changes. Once again, EI-1550 and EI-1530 are important reference documents on this.

As we go back to using filter separators in refuelling aircraft, we do need to be as sure as possible of the sump water detection. To be safe, it is imperative to follow industry (JIG, IFQP/IATA and A4A/ATA) standards and have water controls that meet EI-1596 in the sump or drain line of the filter vessel. Again, following EI-1550 and EI-1530.

Our 1 CC Probe is just one approach, float controls with counterweight floats and other controls that meet the water sensing requirements of EI-1596 are also available and provide proper safety, if tested regularly.

To be sure of the water sensing device, EI-1596 requires a "built-in" "mechanism" "for testing" to ensure that the system works.

Which brings up a point we need to make. There is another standard, EI-1592, which is JUST for sensors that can sense if there is a slug of water travelling through a main pipe. It is not meant to apply to filter separator sump sensing. The devices available that meet EI-1592 do not have a built-in mechanism for testing. The system has to be taken out of service, the probe removed and put into a bucket of water to test it. This is not in keeping with EI-1596 or EI-1550.

Unfortunately, some salesmen appear to not see any difference and are pushing a slug sensor as a sump sensor. While they both sense water, a proper electronic sensor meeting or float made to meet EI-1596 can be safely tested with fuel flowing, even while refuelling aircraft. An EI-1592 sensor simply cannot be tested in place. In addition, if an isolation valve on the drain mounted version of the slug sensor is left closed by accident, the EI-1592 slug sensor is disabled. Just a simple error by an operator can disable the sensor.

The only EI-1592 sensor we know of is the Faudi Slugguard/Drainguard. Although their website and literature clearly indicate it meets EI-1592 and not EI-1596, some people are confused and think this is the same as EI-1596. It is not. The Faudi sensor does not have any built-in mechanism for testing unless you think that removing the vehicle or fuel farm from service, removing the sensor and putting the sensor in a bucket is a "built-in" mechanism for testing.

In addition, their Drainguard version adds an automatic water drain. It is a simple solenoid valve. Automatic drain valves were used widely 30-60 years ago, but the industry had too many problems. First (and most important) if you get that much water, you need to know why. An automatic drain prevents you from knowing you even had water. See EI-1530. Proper quality control requires that you know of any change. The second reason is that these drain valves leak when tiny particles get on the seal. Leaks of jet fuel are a bad thing, so most operators put a pipe plug in them.

Meeting EI-1596 is up to your company policy and contracts with customers and operators. Good sensors made to meet EI-1596 are made by several companies, including Carter, Meggitt/Whittaker, ClaVal and others as well as Gammon Technical Products, Inc...

We know the problem, Fuel volume equals cash flow. If fuel doesn’t flow, there is no dough.

Which makes your job more difficult.

See attached guidelines from A4A and JIG on dealing with the present situation on EQUIPMENT, from a practical point of view. We have added additional suggestions below.

There is an ATA/A4A (USA) release in addition to the JIG Bulletin 128 (International). See links below.

Not using fuel handling equipment can be dangerous in many ways. Fuel is not stable over time and equipment needs to be exercised.

Filters, tanks, hydrant lines and vehicles all need to be periodically flushed, at a reasonable velocity. But what is a reasonable velocity?

We at GTP recommend at least 3 feet per second on suction pipes and 6 feet per second on discharge pipes. In metric measure, that’s about 1 meter per second suction and 2 meters per second discharge.

In filter separators, we recommend achieving the maximum achievable velocity at least once a week for at least 5 minutes.

All of this can be difficulty, especially on long hydrant system runs, if they are not "loops" set up to allow recirculation.

In addition, displacing fuel means a volume must be transferred. Lets take a hydrant line, 8" (200 mm) in diameter and 1000' long, 340 meters.

That pipe alone holds 2,600 gallons/9,800 liters.

To achieve 6 fsp/2 m/s, you must flow it at a velocity of at least 1,000 gpm.

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H M Gammon’s Velocity Formulas (Howard Gammon’s math skills were amazing)

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As an example, 300 gpm calculations:

(GPM/pipe size in inches squared) x 0.4 = FPS (feet per second)

So, 300 gpm divided by 16 (4 x 4 for 4” pipe) times .4 = 7.5 feet per second.

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(LPM/pipe size in mm squared) X 20 = M/s (meters per second)

So, 1,135 lpm divided by 10,000 (4” pipe is approximately 100 mm, so 100 x 100 is 10,000) x 20 = 2.27 m/s.

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The documents below provide a starting point only. Be safe and never assume that fuel is good or equipment is safe to operate if the system has not been used, recirculated or flushed regularly. One oil company recommends all equipment be flowed at least twice a week, to maximum attainable velocity.

Yours may vary, but we agree that equipment must be exercised, filters must be flowed and systems flushed or recirculated.

Microbes grow quickly and a coalescer that doesn't flow is an incubator for microbes.

Jim

https://www.airlines.org/wp-content/uploads/2020/04/A4A-Bulletin-2020.1_Reduced-Operations-and-Decommissioning-Due-to-COVID-19.pdf

http://www.jigonline.com/all-bulletins/