INDUSTRIAL CASE|OIL & GAS|GAS-MOTOR COMPRESSOR · ICE
PJSC UKRNAFTA TEST REPORT · 2400 ENGINE HOURS
Gas-motor compressor 10GKNA: cylinders and compression restored without teardown
PRODUCTXADO revitalizantXADO revitalizant gel (industrial) · XADO VITAFLUSH oil system cleaner
TEST OBJECTGas-motor compressor 10GKNAtwo-stroke engine, 10 power cylinders · serial no. 705, inventory no. 411335
DOCUMENT TYPETest report
under a program approved by the customer
under a program approved by the customer
Key results
↑3.6-20.8%
compression across cylinders, 12-14 → 14.2-15 bar
↓0.12-0.22mm
control cylinder diameter, 355.14-355.29 → 355.01-355.10 mm
↓14-38%
vibration displacement of block and frame, 20.5-88.1 → 9.3-67.4 µm
| COMPONENT | CONDITION AT START OF TESTS | WHAT WAS MEASURED |
|---|---|---|
| Engine, 10 power cylinders | In service, cylinder-to-cylinder compression spread 2 bar (12–14 bar) | Compression and combustion pressure in all cylinders |
| Control cylinders No. 6 and No. 9 | Accumulated wear, scuff marks and scratches; cylinder 9 has a longitudinal score over 0.5 mm deep | Diameters in two sections along two axes |
| Engine block and frame | Continuously operating unit, not taken out for repair | Vibration at 26 control points, three directions |
Compression in all ten power cylinders
| CYLINDER | BEFORE TREATMENT, bar | 2400 ENGINE HOURS, bar | CHANGE |
|---|---|---|---|
| I | 14 | 15 | +7.1 % |
| II | 12 | 14.5 | +20.8 % |
| III | 13 | 14.5 | +11.5 % |
| IV | 13 | 14.5 | +11.5 % |
| V | 14 | 15 | +7.1 % |
| VI | 13 | 14.2 | +9.2 % |
| VII | 13.5 | 14.5 | +7.4 % |
| VIII | 13 | 15 | +15.4 % |
| IX | 14 | 14.5 | +3.6 % |
| X | 14 | 15 | +7.1 % |
Measured at 295-310 rpm, the same operating mode in all three measurements. Compression rose in all ten cylinders, the spread between them 2 → 0.8 bar.
Diameters of the working part of the control cylinders
| CYLINDER | SECTION / AXIS | BEFORE TREATMENT, mm | 2400 ENGINE HOURS, mm | CHANGE, mm |
|---|---|---|---|---|
| No. 6 | 50 mm, axis A | 355.18 | 355.01 | −0.17 |
| No. 6 | 50 mm, axis B | 355.15 | 355.03 | −0.12 |
| No. 6 | 250 mm, axis A | 355.14 | 355.02 | −0.12 |
| No. 6 | 250 mm, axis B | 355.14 | 355.02 | −0.12 |
| No. 9 | 50 mm, axis A | 355.27 | 355.07 | −0.20 |
| No. 9 | 50 mm, axis B | 355.29 | 355.07 | −0.22 |
| No. 9 | 250 mm, axis A | 355.24 | 355.04 | −0.20 |
| No. 9 | 250 mm, axis B | 355.28 | 355.10 | −0.18 |
The diameter decreased because a metal-ceramic layer built up on the worn surface — this is exactly what caused the compression to rise.
Longitudinal score on the working surface of cylinder 9
| SCORE DIMENSION | BEFORE TREATMENT | 2400 ENGINE HOURS |
|---|---|---|
| Depth | over 0.5 mm | no more than 0.3 mm |
| Width | up to 2.5 mm | up to 1.0 mm |
| Length | up to 120 mm | no more than 90 mm |
In the middle part of the score, over a length of up to 7 mm, it has been completely eliminated by the metal-ceramic layer. The dimensions were recorded by the commission during inspection.
Vibration displacement of the engine block and frame, µm
| MEASUREMENT POINT | LEFT, BEFORE | LEFT, 2400 H | RIGHT, BEFORE | RIGHT, 2400 H |
|---|---|---|---|---|
| 1 · vertical, rear side of the block | 48.5 | 18.1 | 24.1 | 31.5 |
| 2 · horizontal, rear side of the block | 64.7 | 56.2 | 64.7 | 47.5 |
| 3 · axial, rear side of the block | 42.2 | 18.0 | 37.3 | 25.6 |
| 4 · vertical, rear side of the frame | 20.5 | 13.3 | 33.3 | 9.26 |
| 5 · horizontal, rear side of the frame | 28.6 | 26.8 | 32.4 | 27.9 |
| 6 · axial, rear side of the frame | 33.2 | 28.6 | 35.2 | 29.0 |
| 7 · vertical, front side of the block | 87.5 | 64.6 | 69.5 | 61.1 |
| 8 · horizontal, front side of the block | 88.1 | 62.2 | 76.1 | 67.4 |
| 9 · axial, front side of the block | 63.6 | 20.0 | 49.3 | 31.2 |
| 10 · vertical, front side of the frame | 44.6 | 20.2 | 34.8 | 21.6 |
| 11 · horizontal, front side of the frame | 56 | 30.9 | 36.4 | 28.5 |
| 12 · axial, front side of the frame | 33.4 | 28.5 | 34.5 | 24.3 |
| 13 · vertical, rear central side of the block | 46 | 41.0 | — | — |
| 14 · axial, rear central side of the block | 46.2 | 31.8 | — | — |
26 control points in three directions, the same points and the same operating mode before treatment and after 2400 engine hours of operation.
Commission conclusion
The commission of PJSC Ukrnafta recorded: the diameters of the working parts of the control cylinders (6 and 9) after a total operating time of 2400 hours decreased by 0.12-0.22 mm owing to the formation of a metal-ceramic coating, which practically completely eliminated the accumulated mechanical wear; the working part of the cylinders has the appearance of a smooth polished surface, through which traces of the former scuffs and scratches are visible but cannot be felt by touch. Eliminating the accumulated cylinder wear with XADO compounds makes it possible to extend the residual service life without shutting down the gas-motor compressor and disassembling it for repair. The vibration level at the control points decreased by 22-53 %, and at individual points of the engine block the vibration displacement — by 1.2-3.2×. Compression readings in all cylinders increased by 6 to 16 % and stabilized: the compression spread decreased 2.5×, from 2 to 0.8 bar. An increase in compression contributes to higher engine power, while a smaller compression spread across the cylinders reduces crankshaft imbalance.
The results apply to the two-stroke engine of a 10GKNA gas-motor compressor under industrial operating conditions at a gas processing plant; on other units and in other operating modes the figures may differ. The original PJSC Ukrnafta report with the commission signatures is provided in full.
Current equivalent
- Revitalizant gel for diesel enginesDiesel engines
- Revitalizant gel for petrol enginesPetrol engines
- Revitalizant gel for cylinder restorationEngine cylinders, deep wear
How such units are treated: