vehazle
Mechanical
- Nov 13, 2004
- 11
Hello All,
I am looking for some assistance in clarifying the calculation of a Class 2 flange per App Y, specifically how to decipher/interpret Y-6.3 (a) (1-4). This whole Y-6.2 section on Class 2 seems overly contorted and hard to follow (at least for me) and I have puzzled over this for a couple of days and finally decided I needed some external input on it. An example calc would sure be nice to add some clarity, but I have been unable to track one down.
I have already generated a calc sheet for a Class 3, Cat 1 flange pair, essentially for the configuration shown in Fig. Y-5.1.3. The problem is that the client changed the bore size on the reducing blind so that BII is now >C/2 which pushes me into Class 2.
The issues I am having are:
1. Y-6.2 & Fig. Y-5.1.2 show that for the reducing flange (Flange II) that there is an integral nozzle or hub, but I only have a blind with central hole (basically configured like Fig. Y-5.1.3). It is unclear to me how to address my configuration when the formula modifications indicated in Y-6.2 are for the nozzle/hub configuration.
2. Y-6.2 (a) (1), et al state that Flange II is assumed to be an App 2 flange for the analysis purposes. I assume this is only an explanatory note and that I do not need to refer back to App 2 for Flange II, but use the modified equations that follow. Can someone confirm this thinking?
3. Y-6.2(a) (2) indicates that Flange II (the App 2 flange) must also be categorized (1, 2 or 3). For my case of a blind with central hole, what would the category be? I was thinking Cat 3 (loose type w/o hub) but I am really not sure on this since the blind configuration doesn’t match very well any of the Fig. 2-4 type sketches.
4. For Y-6.2 (a)(3), there is a different formulation the moment due to pressure as Mp’ with redefinitions of HD’, HT’, hT’ & hD’. I believe these are used only for calculating parameters for Flange II and do not replace the “regular” (non ‘ ) definitions of these terms from Y-3(a) used for the Class 3 calc. This is based on the statement in Y-6.2(a)(4)(f), but can someone confirm my interpretation on this?
I appreciate any insight anyone who has done a Class 2 calc or has experience in App Y calcs that could comment.
Thanks
I am looking for some assistance in clarifying the calculation of a Class 2 flange per App Y, specifically how to decipher/interpret Y-6.3 (a) (1-4). This whole Y-6.2 section on Class 2 seems overly contorted and hard to follow (at least for me) and I have puzzled over this for a couple of days and finally decided I needed some external input on it. An example calc would sure be nice to add some clarity, but I have been unable to track one down.
I have already generated a calc sheet for a Class 3, Cat 1 flange pair, essentially for the configuration shown in Fig. Y-5.1.3. The problem is that the client changed the bore size on the reducing blind so that BII is now >C/2 which pushes me into Class 2.
The issues I am having are:
1. Y-6.2 & Fig. Y-5.1.2 show that for the reducing flange (Flange II) that there is an integral nozzle or hub, but I only have a blind with central hole (basically configured like Fig. Y-5.1.3). It is unclear to me how to address my configuration when the formula modifications indicated in Y-6.2 are for the nozzle/hub configuration.
2. Y-6.2 (a) (1), et al state that Flange II is assumed to be an App 2 flange for the analysis purposes. I assume this is only an explanatory note and that I do not need to refer back to App 2 for Flange II, but use the modified equations that follow. Can someone confirm this thinking?
3. Y-6.2(a) (2) indicates that Flange II (the App 2 flange) must also be categorized (1, 2 or 3). For my case of a blind with central hole, what would the category be? I was thinking Cat 3 (loose type w/o hub) but I am really not sure on this since the blind configuration doesn’t match very well any of the Fig. 2-4 type sketches.
4. For Y-6.2 (a)(3), there is a different formulation the moment due to pressure as Mp’ with redefinitions of HD’, HT’, hT’ & hD’. I believe these are used only for calculating parameters for Flange II and do not replace the “regular” (non ‘ ) definitions of these terms from Y-3(a) used for the Class 3 calc. This is based on the statement in Y-6.2(a)(4)(f), but can someone confirm my interpretation on this?
I appreciate any insight anyone who has done a Class 2 calc or has experience in App Y calcs that could comment.
Thanks