
An oval gear flowmeter measures by displacement. Two oval rotors turn inside a measuring chamber and pass a fixed volume of liquid with each revolution, and the counter records those revolutions as a running total. Nothing is inferred from velocity or from a settled flow profile; the meter measures the liquid itself, which is why this design holds its reading on thick, dark oils that unsettle lighter-duty instruments. The elliptic gear flowmeter name comes from the shape of those rotors, so both terms describe the same instrument.
Because it is a positive displacement flowmeter, the total it reports is volume, not an estimate. A fitter reads the number, writes it in the log and trusts it, which is what fuel and lube-oil accounting actually needs.
The body is an inline flanged casting with a top-mounted round dial and a roller counter. The painted body carries a blue indicator housing and a white top cap, and the dial sits flat on top so someone standing at the pipe can read the total without crouching. Flanged ports bolt straight into the line, and the side adjustment point stays reachable once the meter is in place.
Most of the buyers we ship to are doing one of two things: replacing a worn meter on a fuel transfer, purifier feed or lube-oil filling line, or adding a metering point to a fuel-oil skid being assembled for a vessel or a plant. Chief engineers use the total to reconcile fuel taken on board against fuel burned; workshop teams use it to track oil drawn from a drum or a day tank. This marine diesel fuel and lubricating oil flow measurement meter is built for exactly those duties, and it handles other clean liquids just as well when the body material suits them.
The standard gauge head is a pointer type, entirely mechanical, so it reads at the pipe with no power supply. Where the total has to reach a control room, a logger or a consumption display, the same measuring body can be supplied with an electronic head that gives a signal output.
As a marine flowmeter supplier we keep the range wide — DN 10 to DN 200, cast iron and stainless steel — because one family has to serve a small lube-oil line and a large bunkering main. Three answers decide the build: which liquid the meter will see, how big the line is, and what pressure it will run at. Body material, nominal diameter and pressure rating follow from those, and the head type comes after them.
| Item | Specification |
|---|---|
| Product type | Oval gear (elliptic gear) positive-displacement flow meter |
| Measuring Range | 0.04-340 (m3/h) |
| Accuracy Class | 0.5/0.2 |
| Nominal Diameter | 10-200 (mm) |
| Working Pressure | 1.0-6.4 (MPa) |
| Applicable Medium | Applicable Medium: Different materials are suitable for different liquids, conventional cast iron is suitable for lubricating oil liquids, stainless steel is suitable for most impurity free liquids. Default to pointer type gauge outfit, the signal output electronic gauge outfit can be customized. |
| Gauge head | Pointer type as standard; electronic head with signal output to order |
| Body | Flanged inline body, painted cast finish, top-mounted round dial |
| Totalising | Roller counter beside the dial |
| Installation | Inline between matching flanges, single flow direction |
Two accuracy classes are offered, 0.5 and 0.2, and the smaller number is the tighter instrument: a class 0.2 meter is permitted a smaller deviation from the true volume than a class 0.5 meter across the same band. Both are stated against the indicated value rather than against the dial's full scale, so the tolerance follows what is actually flowing. If the figure has to go into a specification sheet, ask us to confirm how it is expressed for the size you order.
Class 0.5 covers most working duties on a marine diesel fuel and lubricating oil flow measurement meter. Fuel transfer totals, lube-oil top-ups and routine consumption checks are normally run on a class 0.5 instrument, because the number is there to show a trend and catch a loss, not to settle an account to the last litre.
Class 0.2 is the choice when the number has to stand up in a discussion: consumption reported to a charterer or an owner, cost allocation between departments, trial runs on an engine or a boiler, and any figure that ends up in someone else's report. The extra cost buys a tighter permitted deviation — not a different body, and not a different installation.
Remember that the class describes the meter, not the whole installation. Air drawn into the line, a partly closed valve upstream, a meter running below its band and worn rotors after long service all move the reading further than the gap between the two classes. Fit the meter to a clean, air-free line and the class you paid for is the class you get.
Recalibration intervals are set by the operator, the survey regime or the plant's own quality procedure rather than by us. Tell us what your procedure requires and we will confirm what documentation can go with the shipment.
The range runs from 1.0 MPa to 6.4 MPa — roughly 10 bar to 64 bar — which covers fuel-oil transfer, engine fuel supply and return, and lubricating-oil circuits on most vessels and in most plants. The figure you specify for a marine diesel fuel and lubricating oil flow measurement meter should be the highest pressure it can be exposed to, not the pressure it sits at every day.
That distinction earns its keep on a fuel system. A meter that normally lives at a few bar can still meet the pump's shut-off head when a valve closes, or a surge when a quick-acting valve shuts downstream. Rate the body for the worst case it can meet in service and treat normal operating pressure as margin.
Higher ratings bring a heavier body and larger flanges, so there is little point paying for 6.4 MPa on a line that will never pass 1.0 MPa — the extra metal has to be hung on the pipe. The opposite mistake is the expensive one: a body rated below a surge becomes a leak path in an engine room.
Diameter and pressure are chosen together, because the pair sets the flange rating and the flange has to match the pipe you are joining. That is why we ask for both in the same message.
If your commissioning procedure calls for a hydrostatic test above the working rating, say so before the order is placed so the requirement can be checked against the body you are buying. A meter is a measuring instrument, not a relief device: where a line can be isolated and warmed, give trapped liquid somewhere to go with a relief or a bypass.
The standard gauge head is a pointer type. A round analog dial gives the reading at a glance and a roller counter beside it accumulates the total volume, so the meter works with no electrical supply at the metering point — a real advantage on a transfer line where no convenient power exists. The dial carries clear printed figures, which counts for something in an engine room lit by a single lamp.
Where the total has to travel, specify the electronic gauge head. It provides a signal output that can be taken to a panel, a logger or a monitoring system, so consumption can be trended without a fitter walking the line with a notebook. The form of that output is settled when you order: tell us what your panel or logger accepts and we will confirm what can be supplied.
Choose the head with the body, not after it. Both versions share the same measuring chamber and the same flanged body, but the top end is built as part of the instrument, so the head, the diameter, the material and the pressure rating should be settled in one conversation before production starts.
Readability deserves a thought even on the mechanical version. The dial sits on top of the body, so a meter fitted under a low deck or tight against a bulkhead may only be readable from an awkward angle. If the only space available is cramped, describe it and we will confirm what can be arranged to suit.


Buying instrumentation for a vessel or a plant usually comes down to matching the part to the job. Our team at Jiangmen Jiexi Machinery Equipment Co., Ltd. has worked with buyers worldwide since 2013, and we start before the order: confirming the range, thread, connection and mounting you need, checking a model or part number against the equipment on site, and saying plainly where a standard unit stops and custom work begins. After delivery we stay reachable for installation, commissioning and fault-finding, with quality control that includes two extra testing steps beyond industry standard.
Yes. The body is built to measure in one direction, and a meter running backwards gives a total nobody should rely on. Set the body so the flow runs the way it is intended and the dial ends up facing the position your fitter reads from. If the pipe layout is unusual — a vertical run, or a meter tucked in behind a pump — describe it when you order so the arrangement can be checked before the body is built.
It does both. Consumption is the difference between two counter readings over a known period, so the same instrument that totals a transfer also gives you a burn figure. For regular trending, order the electronic head so readings reach a logger or a monitoring screen; for occasional checks, the pointer head and a log book are enough.
Fit a strainer or filter upstream and clean it on a schedule. The rotor clearances are fine, so a few flakes of rust will do more damage than a year of normal service. On a new line, flush the pipe before the meter is installed; on an old line, check the strainer after the first few days of running.
The counter accumulates total volume that has passed through the meter, while the round dial gives the reading at a glance. The scale is volumetric, so a total is recorded in cubic metres or litres depending on how the counter is scaled. Confirm the unit your logs use when you order, and note that the total is volume at line conditions rather than mass.
Order it with the meter. The measuring chamber and the flanged body stay the same, but the top end is built as part of the instrument, so the head is easiest to specify alongside the diameter, material and pressure rating. Tell us which signal your panel or logger accepts and we will confirm what can be matched to it.
That is set by your own procedure — a survey regime, a quality system or an owner's requirement — rather than by a fixed interval from us. Tell us what your procedure calls for when you order and we will confirm what documentation can accompany the shipment. A meter kept on clean liquid and never run dry is a long way from needing attention.