High temp cracking in steam pipework
High temp cracking in steam pipework
(OP)
Hello all
Am having trouble with high temperature cracking of a gas turbine steam dump line. The 600mm dia line is made of CrMo and C/S welded together, though cracking is evident circumferentially in both materials. Cooling water is injected into the pipe when in operation at around 40 degC and steam is run under vacuum at approx 440 deg C.
Problem is I have to repair / replace this pipe and need to come up with refabrication in a different material or replacement of the C/S section with full length CrMo, though with the established cracking in the CrMo am not sure a replacement with the same material is feasible.
Hope this makes some sense?
Regards
JonD71
Am having trouble with high temperature cracking of a gas turbine steam dump line. The 600mm dia line is made of CrMo and C/S welded together, though cracking is evident circumferentially in both materials. Cooling water is injected into the pipe when in operation at around 40 degC and steam is run under vacuum at approx 440 deg C.
Problem is I have to repair / replace this pipe and need to come up with refabrication in a different material or replacement of the C/S section with full length CrMo, though with the established cracking in the CrMo am not sure a replacement with the same material is feasible.
Hope this makes some sense?
Regards
JonD71
JonD 71
Australia





RE: High temp cracking in steam pipework
This may not be your problem but is the first thing that pops up in a mixing situation.
Can you come back with a little better description of the cracking.
What is the configuration of the water spray nozzle?
RE: High temp cracking in steam pipework
Thanks for the prompt response.
Cracking has been identified by a metalurgist as temperature related and is multi facited circumfernetially around the pipe. The water injection nozzles are present as this is the steam bypass line and spray marginally constantly to improve their reaction time during steam discharging. My main problem is selection of a material for replacement or repair.
Thanks again
JonD71
JonD 71
Australia
RE: High temp cracking in steam pipework
With your present setup a change in material will not help. You have to stop the thermal cycling on the metal surface.
Your system should work like desuperheater in a steam line.
RE: High temp cracking in steam pipework
RE: High temp cracking in steam pipework