-Raw Material Quality Criteria
Grandpipe determines quality criteria for all raw materials used. Raw materials are delivered with vendor certification demonstrating their compliance with acceptance criteria of Grandpipe. Additionally, all raw materials are tested as sampling base prior to their use.These tests ensure that pipe materials comply with specifications as stated.
Main raw material groups used in GRP pipe production are mentioned below:
>Filler (Silica Sand)
-Finished Good Quality Criteria
All finished goods (GRP Pipes) are subjected to following control steps:
>Barcol Hardness ( Barcol: Surface Hardness Unit used for generally GRP composites)
>Hydrostatic Leak Tightness Test ( Two times of nominal pressure)
On a sampling basis, following control steps are performed:
>Inner Surface Control Under The Deflection Load.
>Structural Failure Control Under The Deflection Load.
>Composite Structure Analysis and Design Verification
>Hoop (Circumferential) Tensile Strength
>Axial (Longitudinal) Tensile Strength
Control steps based on sampling method define initial physical properties of pipes. Long term performances of the pipes are considered at following articles. These test are performed according to defined Grandpipe quality criteria. This criteria is determined by referring upper limits of local and international standards. Test results are the main parameters to get the quality in assurance for finished good pipes.
Long Term Performance Criteria
General requirement of whole standards is to obtain minimum performance criteria. In GRP pipe systems, long term performance is the main quality criteria beyond short term or initial performance.All quality criteria of Grandpipe are designed including long term performance. By considering several operating conditions, mostly important items are as follows:
>Long Term Specific Ring Stiffness
>Long Term Ring Bending Strain
>Hydrostatic Design Basis (HDB)
>Long Term Strain Corrosion
In addition to main performance criteris, Grandpipe GRP pipes are tested for:
>Ultraviolet (UV) Resistance
>Resistance to Different Operating Temperature
> Fire Resistance