Pipe Category and Hydrotest
Pipe Category and Hydrotest
(OP)
Hi All,
I am new in the piping design world, and I was asked to design a spool with a hydrotest package for a gas line operating at 1,200 psi at a north region in Canada.
I choose the following materials for the spool:
· The pipe can be a NPS 1 XS A-106 (WT 0.133 in)
· A NPS 2: NPS 1 reducer made of A-105N
· Weld neck flanges - ANSI 600 – A105N
· A ¾ “ TOR – 3000# - A105N
I did not specify which Category to use I II or III, since I am a bit confused as to what the categories really represent
From what i read on CSA Z662, categories I, II, III represent the notch toughness and different exposed temperatures (I might me wrong).
Therefore, since this spool piece is in a facility and can experience temperatures as low as -45 C, would it be saved to assume that a Category II or Category III pipe is required?
Also, Table 5.3 in CSA Z662 indicates pipe types and their limitations in category, so how come a pipe made out of A-106 is not applicable to Cat II and Cat III applications?
I would really appreciate any advice or comment.
Thank you
I am new in the piping design world, and I was asked to design a spool with a hydrotest package for a gas line operating at 1,200 psi at a north region in Canada.
I choose the following materials for the spool:
· The pipe can be a NPS 1 XS A-106 (WT 0.133 in)
· A NPS 2: NPS 1 reducer made of A-105N
· Weld neck flanges - ANSI 600 – A105N
· A ¾ “ TOR – 3000# - A105N
I did not specify which Category to use I II or III, since I am a bit confused as to what the categories really represent
From what i read on CSA Z662, categories I, II, III represent the notch toughness and different exposed temperatures (I might me wrong).
Therefore, since this spool piece is in a facility and can experience temperatures as low as -45 C, would it be saved to assume that a Category II or Category III pipe is required?
Also, Table 5.3 in CSA Z662 indicates pipe types and their limitations in category, so how come a pipe made out of A-106 is not applicable to Cat II and Cat III applications?
I would really appreciate any advice or comment.
Thank you





RE: Pipe Category and Hydrotest
For your information:
Category I = no proven notch toughness required
Category II = proven notch toughness required both in terms of absorbed energy in a Charpy impact test (or DWTT) as well as in the percent shear area measured on the Charpy impact test (or DWTT) specimens (minimum 60% shear area averaged across three specimens with no single specimen below 50%).
Category III = proven notch toughness required as measured by absorbed energy only, with no measurement of shear area on fracture surface.
Thus, Category I is the least stringent, Category III is more stringent, and Category II is the most stringent.
Study CSA Z662 Clauses 4 and 5 and CSA Z245.1 carefully for details.
RE: Pipe Category and Hydrotest
Thank you so much for replying to my thread at 11pm and I really appreciate your feedback!
I will review Z662 and Z245.1 as you recommended.
Cheers
RE: Pipe Category and Hydrotest