Pre-stressed Vacuum Insulated Tubing & Casing for Oil Thermal Recovery
Pre-stressed Vacuum Insulated Tubing & Casing for Oil Thermal Recovery
Product DescriptionShengji vacuum insulated tubing & casing uses water-based fiber cloth material with a three grade vacuum pump equipment, automatic welding machine and MT. These guarantees a high degree of vacuum level that meets the insulation grades D and E.
These vacuum insulated tubing & casing use an effective getter to ensure the tubing insulation grade do not decrease after a long time of outdoor storage. Shengji vacuum insulated tubing & casing are reusable. They retain desired insulation properties after being used several times. Shengji people are dedicated to the development of new products. Our products constitute almost 40% market share in Shengli Oilfield VIT market at the moment.
The pre-stressed insulated tubing is mainly consist of inner tube, outer tube, heat insulation material, coupling, etc. In its structure, put pre-stress on the inner tube to make up the different thermal elongation of the inner and outer tube. At normal temperature, the inner tube is in tension condition. When the temperature increases gradually, the tensile stress decreases. When the temperature increases constantly, the tension condition of the inner tube turns to its bearing condition. The pre-elongation of the inner tube decreases the compression stress after the heated elongation. As a result, the insulated tubing run and maintain in good condition.
1.Insulated grade D and E.Advanced 3-level vacuum pump, automatic welding machine and online radiographic.
2.Long lifetime.During outdoor storage, insulation level don't reduce.
3.Inner tube and outer tube connections are both available.
SpecificationsA. VIT Performance Level
| Heat-insulating property level | Heat conductivity coefficient,W/(m·℃) |
| A | 0.06≤λ<0.08 |
| B | 0.04≤λ<0.06 |
| C | 0.02≤λ<0.04 |
| D | 0.006≤λ<0.02 |
| E | 0.002≤λ<0.006 |
B. VIT Specification
Specification | Basic parameter | ||
Outer tube OD x Inner Tube ID(in x in) | Steel grade | Connection | Thread |
3 1/2 x 2 3/8 |
N80 L80 P110
| Inner connection Outer connection Extreme line connection
| 3 1/2 USS |
4 1/2 x 2 7/8 | 4 1/2 BC | ||
4 1/2 x 3 1/2 | 4 1/2 BC | ||
5 x 3 1/2 | 5BC | ||
5 1/2 x 4 1/2 | 5 1/2 BC | ||
7 x 5 1/2 | 7 BC | ||
C. Main Performance Parameters
| Heat conductivity coefficient (Inner tube inside wall 350℃) ,W/(m·℃) | Normal temperature tensile load, kN | Normal temperature tensile load, kN | Normal temperature tensile load, kN | Flatness % | |||
| Normal Temp. | Gas injection | Normal Temp. | Gas injection | ||||
| YG88X40 | 0.002~0.02 | ≥402 | 32 | 20 | 30 | 28 | ≤0.2 |
| YG88X50 | 0.002~0.02 | ≥432 | 32 | 20 | 30 | 28 | ≤0.2 |
| YG114X62 | 0.002~0.02 | ≥506 | 32 | 20 | 26 | 24 | ≤0.2 |
| YG114X76 | 0.002~0.02 | ≥537 | 32 | 20 | 26 | 24 | ≤0.2 |
| YG127X62 | 0.002~0.02 | ≥615 | 32 | 20 | 23 | 21 | ≤0.2 |
| YG127X76 | 0.002~0.02 | ≥615 | 32 | 20 | 23 | 21 | ≤0.2 |
Production Process
InspectionA. X-ray flaw detection
X-ray flaw detection equipment carry out the testing on the welding seam to guarantee the welding effect and insulating capability.
B. Heat conductivity coefficient test
Heat conductivity coefficient 100% test, record the performance parameter and the index curve for each piece of insulated tube.
Quality Control
