PDal
Mechanical
- Oct 21, 2013
- 2
I am having a discussion with a vendor about if a flange is acceptable per ASME B16.5. The flange in question is a 1 1/2" 150# Blind Flange (without a hub) that has a has a hole drilled in the center to accept a 1.9" O.D. probe with a 1/2" bore. The probe will be attached to the flange with a full penetration weld.
From my understanding of ASME B16.5, the blind flange must have a hub dimension at least equal to a standard 1 1/2" slip-on flange in order to still be classified as an ASME B16.5 flange. Without the hub, I would understand this flange to be classified as an unlisted component. Is my understanding correct?
I have tried to find information regarding the use of flanges with hubs for instrumentation, but have not been able to. The only thing I have found is that the companies that manufacture sample probes (as well as flanged thermowells) all look to use blind flanges that do not have a hub. I know that you are allowed to use blind flanges without hubs when reducing size as long as you follow the dimensions in Table II-6 of ASME B16.5, but are required to use hubs after certain sizes.
Is there something I am missing that allows the use of blind flanges without hubs for sample probes & flanged thermowells?
Thank You
From my understanding of ASME B16.5, the blind flange must have a hub dimension at least equal to a standard 1 1/2" slip-on flange in order to still be classified as an ASME B16.5 flange. Without the hub, I would understand this flange to be classified as an unlisted component. Is my understanding correct?
I have tried to find information regarding the use of flanges with hubs for instrumentation, but have not been able to. The only thing I have found is that the companies that manufacture sample probes (as well as flanged thermowells) all look to use blind flanges that do not have a hub. I know that you are allowed to use blind flanges without hubs when reducing size as long as you follow the dimensions in Table II-6 of ASME B16.5, but are required to use hubs after certain sizes.
Is there something I am missing that allows the use of blind flanges without hubs for sample probes & flanged thermowells?
Thank You
