mpp power tube cable protection tube use introduction!mpp power tube cable protection tube use introduction!
Trenchless technology has not quietly emerged in China in the twentieth century. It has been applied to the trenchless construction of various pipelines. Among them, the special working environment of power pipelines has become the top priority. The long-term operation of power cable exhaust pipes is around 70ºС. And must withstand the external pressure of underground muddy water. In the early days, LDPE solid wall pipes or LDPE spiral pipes (hereinafter collectively referred to as PE pipes) were mostly used as trenchless cable bushings, but the strength of PE pipes decreased greatly when the temperature was above 40ºС (70ºС strength decreased by 2/3). The directional drilling was completed to lay the LDPE pipe. It was found that the PE pipe was deformed by external force, which affected the normal laying of the cable in the later period, so it was proved that the LDPE pipe could not be used for the power pipe. To this end, the Shanghai Electric Power Company issued the “Notice on Standardizing Technical Requirements for Directional Drilling Cable Discharge Pipes and Pipes” in 2003 (that is, Document No. 469 of the Shanghai Electric Power Division Jianzi ), and began small-scale production and use Trenchless MPP pipe.
First, MPP power tube product introduction:
MPP pipe is made of polypropylene as the base material and modified by formula, called modified polypropylene (MPP) pipe, and the cost is higher; while PE pipe is extruded with high-density polyethylene (LDPE, HDPE) as raw material Molding, the cost is relatively lower. However, because it is not easy to distinguish from the appearance whether the pipe composition is modified polypropylene (MPP) or high-density polyethylene (HDPE), some manufacturers are impersonating MPP with LDPE under the drive of interest, and even more are made of LDPE recycled or scrap The pipes pretend to be MPP pipes. Due to the influence of cost and price, some originally regular manufacturers either gave up MPP pipe production or entered the ranks of falsification; such uneven conditions have left serious security risks for the cable laying of power projects. The cable runs at a high temperature of about 70ºС for a long time, and the strength of the PE tube drops significantly (the strength decreases by 2/3 at 70ºС) when the temperature is above 40ºС. It is softened and deformed by external forces, which greatly affects the maintenance of the cable in the later period.
Second, product physical properties
The main physical and mechanical properties of MPP tube
1 Density, g / cm3 0,91-0,96 GB1033-86
2 Sliding friction coefficient
3 Tensile strength, (23 ±, 2) ℃, Mpa, Tensile strength (70 ±, 2) ℃ ≥24,0, ≥18,0 GB / T1040-92
4 Tensile strength of welding (23 ±, 2) ℃, Mpa ≥21,6 GB / T1040-92
5 Bending strength, (23 ±, 2) ℃, Mpa ≥37,0 GB / T9341-2000
6 Bending, modulus of elasticity, Mpa 1000-1200 GB / T9341-2000
7 Flat test (1/2 of pipe diameter, -5 ℃) does not break GB9647-88
8 Vicat, heat resistance (10N, 50 ℃ / h), ℃ ≥120 GB / T1633-2000
9 Out of roundness, mm 3,6-5,0 GB / T13633-2000
10 The minimum allowable bending radius, m ≤75D
11 Material Qualification Modified Polypropylene MPP ASTME168-99
12 Drop weight impact test (-5 ℃ / 8h, R20) D> 160,10kg * 2m D≤160,6kg * 2m D≤125,5kg * 2m 9/10 not broken
3. Raw materials
Take PP powder (modified polypropylene) as the main masterbatch.
4. Connection method
Use the welding machine to hot-melt butt joints. The junction of the fused mpp cable protection tube is about 200 degrees, and it cannot exceed 22 degrees. When the temperature is reached, the two ends can be butted. (Because the connection method of the MPP tube is hot melt welding, the welding port is not good, it will damage the cable or may be flattened, so the MPP power tube must be made of new materials)
Five, product color
MPP power tube is orange
6. Product Length
Generally it is 6 meters / root. If the price of the customer ’s PVC power pipe is large, in order to reduce the cost (the freight and welding fee can be made 6-12 meters / root).
Seven, product features are introduced in detail
1. MPP power tube has excellent electrical insulation.
2. MPP power tube has high heat deformation temperature and low temperature impact performance.
3. The tensile and compressive properties of MPP power pipes are about higher than HDPE.
4. The MPP power tube is light and smooth, with low friction main force, and can be connected by hot fusion welding.
5. The long-term use temperature of MPP power tube is 5 ～ 70 ℃.
8. Product Scope
The utility model can be applied to pipeline projects of municipal administration, telecommunication, electric power, gas, running water and heat.
Urban and rural non-excavation horizontal directional drilling power draining works, and lighting excavation power draining works.