Mini-Bore Precision Gear Flow Meter
Precision helical/spur counterpart, DN5 (by quote) to DN25, PN40 MPa
Volumetric positive-displacement on interlocking helical or spur gears
Viscosity 0.6 to 200 mPa·s, ±0.5 % of rate base / ±0.2 % precision grade
Diesel wet-flow calibrated per JJG 667-2010, two-year battery LCD
- 304 / 316L / PEEK / PTFE wetted parts; chemical-dosing-grade options the larger PD flagship body does not stock
- BSP threaded G1/8 to G1 process connection for OEM-skid integration; 4-20 mA / RS-485 Modbus RTU / square-wave pulse output stack on one body
- No straight-pipe requirement upstream or downstream; the gear chamber meters volumetric displacement, not flow profile
- Out of scope: gas / steam / wet-gas (no liquid film, no seal), abrasive slurry (scores gear teeth), sub-3 cSt water billing at <±1 %
Photo pending; small-bore gear meter, threaded BSP body, EH6400A battery LCD head
DN5 to DN25 mini-bore precision gear meter
Interlocking helical / spur gears · BSP threaded body · battery LCD or 4-20 mA / RS-485 transmitter
The LW series (LW-01 through LW-25); precision gear PD for small-bore high-pressure service the larger flagship does not fit: chemical injection, hydraulic test benches, fuel-injection rigs, lab dosing. Two helical or spur gears displace a fixed crescent volume per revolution; diesel wet-cal per JJG 667-2010. DN5 to DN25 BSP, PN1.6 to PN40 MPa, 0.6 to 200 mPa·s. 304 / 316L / PEEK / PTFE wetted. Battery LCD or 4-20 mA / RS-485 / pulse output. Ships 5–7 business days.
Benefits
- PN up to 40 MPa hydraulic-rated body: the highest pressure grade on our PD series; test-bench, aerospace rigs, well-head injection.
- DN5 to DN25 mini-bore footprint: G1/8 to G1 BSP threaded for OEM-skid integration; 0.1 to 10 000 L/h DN-dependent.
- 304 / 316L / PEEK / PTFE wetted parts: PEEK and PTFE handle acids, alkali, solvents, and pharma additives.
- Battery-LCD head, two-year battery life: instantaneous flow plus cumulative total, glove-readable; no external power, no Ex.
- 4-20 mA / RS-485 Modbus / pulse output: stack on one body; segmented K-factor compensation extends usable turndown beyond 1:10.
- Diesel wet-flow calibrated per JJG 667-2010: K-factor stamped on the data plate, ISO 9001 cert.
- Lead time 5–7 business days from the factory, versus 8–12 weeks at Grade-1 small-bore vendors.
Configure your build.
Pick DN, working pressure, wetted material, output, and accuracy grade. The configurator returns the PF-OG-LW model code and a ballpark unit price; engineering replies with a sized K-factor quote within one business day.
Your Configuration
PF-OG-LW-15-1.6-B-S-S-ELZ-N
DN15 (G1/2), PN1.6 MPa, 304 stainless, standard viscosity 0.6-200 mPa·s, standard −20 to +60 °C, battery-LCD head, passive (no transmitter output), ±0.5 % of rate base accuracy.
Estimated unit price
Verified after engineering review
$620
✓ Diesel wet-flow calibrated, JJG 667-2010 / ISO 9001 cert
✓ K-factor stamped on data plate per individual meter
✓ Reply within 4 business hours
✓ K-factor stamped on data plate per individual meter
✓ Reply within 4 business hours
Typical applications
Four small-bore applications where this precision gear meter is the right pick.
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Chemical-injection skid
OEM dosing skids on PEEK or PTFE at 0.1 to 500 L/h. Battery LCD plus 4-20 mA into the skid PLC.
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Hydraulic test bench up to 40 MPa
Valve, manifold, and actuator qualification on mineral oil at 20-40 MPa. Pulse output drives the bench DAQ.
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Fuel-injection and small-engine test rig
Gasoline and diesel dosing at 3 to 250 L/h with the low-viscosity (L) code. Pulse output into the rig counter.
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Lab additive blending and pharma dosing
Benchtop or pilot dosing on 316L or PTFE at 0.1 to 50 L/h. RS-485 Modbus integrates with lab data systems.
Specifications
| Measurement principle | Volumetric positive-displacement; two interlocking precision gears (helical or spur geometry per build) in a crescent chamber displace a fixed cavity volume per rotor revolution; direct discrete-pulse volumetric metric, no Reynolds-number dependence, no calibration shift with viscosity within the design range |
|---|---|
| Reference standards | JJG 667-2010 (China national metrological verification regulation for liquid volumetric flow meters); reference-level conventions used in API MPMS Chapter 5.2 small-volume-prover custody practice (cert is buyer-arranged with notified body, not factory-supplied) |
| Pipe size | DN5 (G1/8, body dimensions by quote; not a standard row) / DN8 (G3/8) / DN9-10 (G3/8) / DN10 (G1/2) / DN15 (G1/2) / DN20 (G3/4) / DN25 (G1) |
| Model code | LW series; LW-01 (DN5) / LW-08 (DN8) / LW-10 (DN10) / LW-15 (DN15) / LW-20 (DN20) / LW-25 (DN25), with selection-code positions for special mark (T high-temp / N high-viscosity / L low-viscosity), material (B 304 SS / C 316L / P PEEK / F PTFE), pressure (.2 to .40 for PN1.6 to PN40 MPa), counter, signal, and flange. Full build per the LW selection matrix (e.g. LW-B-15.4-EH-RS = 304 SS, DN15, PN4.0 MPa, EH6400A battery LCD, RS-485 Modbus output). Configurator emits the full PF-OG-LW string; LW-XX is the model body identifier. |
| Flow range | DN5: 0.1-10 L/h / DN8: 3-50 L/h / DN9-10: 5-250 L/h / DN10: 10-500 L/h / DN15: 30-3000 L/h / DN20: 50-5000 L/h / DN25: 100-10 000 L/h (published rows; K-factor data-plate-stamped per individual meter) |
| Working pressure | PN1.6 / 2.5 / 4.0 / 6.3 / 20 / 40 MPa; the highest pressure grade on the ProFlow positive-displacement series; PN20 and PN40 MPa bodies use thicker walls and tighter clearance discipline for hydraulic-test and high-pressure-injection service |
| Medium temperature | −20 to +60 °C standard build / up to +120 °C high-temperature build (selection-code T) |
| Viscosity range | 0.6 to 200 mPa·s range; low-viscosity (L) selection code for ≤2 mPa·s aviation gasoline and light solvents; high-viscosity (N) selection code for ≥200 mPa·s heavy hydraulic and lube service |
| Accuracy | ±0.5 % of rate (base grade) on a freshly calibrated meter; ±0.2 % of rate precision grade on a tighter-clearance build (suffix J); the tighter grade trades turndown for accuracy per body |
| Repeatability | ±0.05 to ±0.1 % typical, dominated by mechanical-clearance stability between calibrations |
| Turndown | 1:10 per body per viscosity range on the ±0.5 % grade; 1:5 on the ±0.2 % precision grade; segmented K-factor compensation on the battery-LCD head linearises piecewise across up to ten flow segments for extended usable range |
| Wetted material | 304 stainless / 316L stainless / PEEK / PTFE per medium chemistry; PEEK and PTFE for aggressive acid / alkali / solvent / pharma-utility injection; the larger PD flagship body does not stock PEEK or PTFE wetted parts |
| Gear material | Hardened stainless on metallic bodies; PEEK gear set on PEEK-bodied chemical-injection build |
| Connection | BSP threaded G1/8 / G3/8 / G1/2 / G3/4 / G1 per DN (standard OEM-skid plumbing); flange option by selection code (DIN / ANSI 150/300/600 lb) for inline mounting |
| Counter / display | EH6400A battery-LCD head; instantaneous flow + cumulative total + single-cumulative quantity, two-year battery life on the standalone build; mechanical totalizer (passive, no power); transmitter-only build (no display, signal output only) |
| Output signal | GF photoelectric square-wave pulse 3-wire (high > 9 V / low < 0.5 V, max 1 km cable); MF 4-20 mA two-wire or three-wire (DC12 V or DC24 V loop-powered); BELZ-RS RS-485 Modbus RTU (full register map for instantaneous flow + total + single-cumulative quantity); stack one signal per body |
| Applicable media | Liquid only; refined fuels (gasoline, diesel, jet A-1), lube and hydraulic oil, mineral oil hydraulic-test fluid, heat-transfer oil at operating temperature, acids / alkali / solvents (on PEEK or PTFE build), pharma utility additives, lab dosing fluids, well-head chemical-injection fluids |
| Power supply | DC3.6 V internal lithium battery (two-year life on standalone LCD); DC12 V or DC24 V external on 4-20 mA and RS-485 transmitter builds; passive (no power) on mechanical totalizer |
| Hazardous-area cert | Ex d IIBT4 housing on transmitter build; mechanical-only and standalone battery-LCD are passive and need no Ex certification; the no-electronics-in-pipe ATEX-by-design option |
| Ingress protection | IP65 standard on transmitter housing; IP66 / IP67 by special order (factory-confirmed at quote) |
| Ambient temperature | −10 to +60 °C (transmitter electronics) |
| Calibration | Diesel-oil wet-flow calibration on factory loop per JJG 667-2010 traceability; K-factor stamped on the data plate per individual meter; ISO 9001 calibration certificate; water calibration explicitly forbidden on cast bodies (water rusts the gear set) |
| Maintenance | Three-month transmitter inspection cycle (battery, signal continuity, cable integrity); annual rotor-clearance check on continuous service; install line filter upstream (the build mandates an upstream filter to keep particulate out of the gear mesh) |
| Lead time | 5–7 business days from factory |
Installation
Five field rules for a clean install and a stable pulse train.
- Install a line filter upstream; mandatory The install section opens with “a matching filter shall be installed before the flowmeter.” 40-100 µm sintered or pleated stainless is the working rule for chemical-dosing and hydraulic-test service. One particulate jam scores the chamber permanently.
- Mount the gear shaft horizontal, dial face up Pipe can run horizontal or vertical, but the gear shaft itself must be horizontal; otherwise bearing wear is asymmetric and the meter drifts off K-factor faster. The LCD face rotates in 90° steps for sight-line.
- Throttle INLET, on-off OUTLET. Open slowly. Water-hammer is the leading cause of rotor damage on a precision gear meter; never snap-open a valve upstream of the body at full line pressure.
- De-aerate the line on first fill, prime with diesel before pressurizing The build forbids water calibration / water break-in on the cast body. Air pockets cause over-registration; the chamber displaces gas the same as liquid.
- No steam-cleaning the chamber; run 50-80 % of rated max in continuous service Steam through the gear chamber damages bearings and clearance. Jacket the body shell only for hot-tracing, never through the wetted chamber.
Frequently asked questions
How is this different from the oval-gear flagship under the same series?+
Same PD physics, different rotor geometry and operating range. The oval-gear flagship runs DN10-DN200, PN up to 6.3 MPa, −20 to +200 °C on the high-T build; the workhorse for refinery custody, lube-oil billing, food syrup, and warmed HFO. This mini-bore precision gear meter runs two interlocking helical or spur gears (not oval) in the same crescent-displacement geometry, from DN5 to DN25, with the build opening working pressure up to PN40 MPa hydraulic and adding PEEK and PTFE to the wetted-parts list.
Can it really hold PN40 MPa, and when do I actually need that pressure?+
Yes. The build offers PN1.6 / 2.5 / 4.0 / 6.3 / 20 / 40 MPa as ordered pressure codes; the PN40 MPa build is a real published row, not an estimate. PN20 and PN40 MPa serve three concrete applications: hydraulic-test-bench OEMs running mineral-oil rigs at 20 to 40 MPa qualifying valves, manifolds, and actuators; aerospace and earth-mover hydraulic test rigs; and oilfield well-head chemical-injection where line pressure follows the production pressure into the 20-40 MPa range. Below 6.3 MPa, specify a lower PN code; the lower-pressure build is dimensionally smaller and lighter and costs less.
What ships, what cert, and what is the lead time?+
Lead time is 5 to 7 business days from the factory. Each order ships with the gear meter assembled in the ordered body material and working pressure, K-factor stamped on the data plate from the diesel-oil wet-flow calibration loop (the build explicitly forbids water calibration on cast bodies; water rusts the gear set), an ISO 9001 calibration certificate per JJG 667-2010 traceability, the ordered counter or LCD head (battery-LCD, 4-20 mA transmitter, RS-485 Modbus, or pulse-output build), and BSP threaded fittings or flange face per the order code. Ex d IIBT4 hazardous-area housing applies to the transmitter build only; the standalone battery-LCD and mechanical-only counter are passive and need no Ex certification. The factory does not ship custody-transfer accreditation, OIML R 117, MID notified-body certificates, or third-party sanitary / food-direct-contact / pharma-grade certification; those are buyer-arranged with the notified body if the project demands them.
Need a precision gear meter on a dosing skid or hydraulic rig?
Send DN, medium, viscosity, flow, and rig pressure. Engineering returns a sized K-factor quote in one business day.