CuMo
Mechanical
- May 1, 2007
- 146
Hi all.
We are designing a BEU heat exchanger to PD5500
where shellside cylinder, tubesheet and shellside dished end are forged from ASTM-336-F11-3 (UNS K11572).
Tubeside channel is a known territory so nothing to worry about here.
Due to thickness shellside components are subject to PWHT.
ASTM A336-F11-3 isn't listed in PD5500. There are some CrMo listed in Table 4.4-1
but classification is to BS EN 10222-2 (For forgings).
My first reaction was to compare chemical compositions but nothing really matches 100% so I gave up.
Then I had a look in ASME IX and ASME VIII-1
where for P4 materials a minimum holding temperature of 650 deg C is recommended.
Some refinery specs which I have access to describe P4 materials as (1.25 Cr – 0.5 Moly) and suggest
a PWHT temperature range of 1275 deg F +/- 25 deg F ( 677 deg C to 704 deg C)
I believe I'm on the right track but can't find a route or statement in PD5500
which I can use to justify my approach.
Any comments welcome!
We are designing a BEU heat exchanger to PD5500
where shellside cylinder, tubesheet and shellside dished end are forged from ASTM-336-F11-3 (UNS K11572).
Tubeside channel is a known territory so nothing to worry about here.
Due to thickness shellside components are subject to PWHT.
ASTM A336-F11-3 isn't listed in PD5500. There are some CrMo listed in Table 4.4-1
but classification is to BS EN 10222-2 (For forgings).
My first reaction was to compare chemical compositions but nothing really matches 100% so I gave up.
Then I had a look in ASME IX and ASME VIII-1
where for P4 materials a minimum holding temperature of 650 deg C is recommended.
Some refinery specs which I have access to describe P4 materials as (1.25 Cr – 0.5 Moly) and suggest
a PWHT temperature range of 1275 deg F +/- 25 deg F ( 677 deg C to 704 deg C)
I believe I'm on the right track but can't find a route or statement in PD5500
which I can use to justify my approach.
Any comments welcome!