What grade of ductile iron pipe is most suitable for your project?

According to the EN545 standard, the pressure testing ductile iron pipe​ shall be carried out on all fittings before the application of their external and internal coatings, except for the metallic zinc coating of pipes which may be applied before the test, No leakage or sweating should be detected during test.

Note: The works hydrostatic pressure is less for fittings than for pipes because the shape of the fittings makes it difficult to provide sufficient restraint to high internal pressure during the test.

To fully understand EN545′s control over leak tightness, we must examine three core concepts: PEA, PMA, and PFA. Together, they constitute a scientific system for evaluating and ensuring pipeline leak tightness.
1. PEA – Permissible Operating Pressure
This refers to the maximum allowable internal pressure within a pipeline system at its maximum operating temperature, ensuring long-term, safe, and stable operation.

PEA =PMA+5bar

 2. PMA – Maximum Allowable Working Pressure

This refers to the maximum internal pressure that the piping system can regularly withstand at room temperature, including surge pressure.

PMA=PFA*1.2

3. PFA – Permissible Test Pressure
This refers to the maximum pressure a pipeline can withstand within a relatively short period of time after installation and before commissioning.   

PFA = (20 x e_min x R_m) / D x S_F 

• Taking k9 ductile iron pipe as an example,  e_min is the minimum wall thickness of the pipe, mm.
• R_m is the minimum tensile strength, N/mm².
• D is the average diameter of the pipe, mm.
• S_F is the safety factor.

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