Hydrotest Pressure for Ductile Iron Piping as per BE EN 545

[syed77pda]

Hi All,

I have a situation where the ductile Iron pipe of 8" Piping needs to be hydro tested as per BS EN 545. The design pressure is 6 Bar.
As per BS EN Code, Test Pressure= 1.5 PFA + 5 Bar. This is giving the Test Pressure Value as 29 Bar. I,am confused why the piping has to be
tested to so high pressure when the Design Pressure is just 6 Bar. Moreover the piping is socket welded. Kindly help.

 

[bimr]

Ductile iron pipe is not socket welded, but has spigot and socket joints.

The hydrostatic test pressure is generally 1.5 times the design pressure.

Design Pressure - the pressure used in the design of a pressure component together with the coincident design metal temperature, for the purpose of determining the minimum permissible thickness or physical characteristics of the pressure boundary. Design pressure for vessels is shown on the fabrication drawings and for piping, the maximum operating pressure is indicated on the line list. The design pressure for piping is the larger of 110% of the maximum operating pressure or 25 psi over the maximum operating pressure.

Suggest that further research is necessary on your part.

 

[rconner]

I believe the required hydrostatic pressure test (expression) the OP provided is intended to be for a "type", or sort of proof test, to be performed by the manufacturer (or fabricator) on a representative DN of various size groupings of pipes (and the pipes/joints with the most unfavorable/applicable conditions of manufacture as explained in the standard). I also believe the intent of the requirement is that once such testing is satisfactorily performed, the purchasers of such other pipes to be installed in the field may have some confidence that the pipes or joints etc. like the type test pipe will perform once they are installed on their projects (and subjected to some reasonable level of service pressures and transients etc).
Once this explanation/elaboration is offered maybe the OP can more thoroughly describe exactly what they are after, or what their specific concern with this requirement is?