Flange 4" 150 RF Blind c/w 2" NPT Center Tap A105 N

[SNOW111]

Hello everybody,
Can anyone please send me a photo were the flange with the given description is shown?
Flange 4" 150 RF Blind c/w 2" NPT Center Tap A105 N
Any help is appreciated.
Thank you.

 

[BigInch]

I'd think it would be for an instrument connection, something like this, but the "1/" seems to be missing before the "2", ie. as "1/2 inch".
Unless you have a very, very large diameter and very, very thick flange.

 

[SNOW111]

Dear BIgInch
Thank You for your reply.
Can you please explain why that use the word blind and after that NPT center tap?
Am I missing something?
Thank you.

 

[BigInch]

Sorry! I missed the blind. Guess we know who's blind today.

In that case it is not the above at all. The tap is through the blind flange's thickness, right in the center of the flange. Right in the middle of the "O"
In which case a 2" probably fits.

 

[SNOW111]

Thank You for your help BigInch.
Regards.

 

[bimr]

Would think that it would look something like this:

 

[SNOW111]

Thank You for your answer Bimr.
Regards

 

[BigInch]

Wouldn't that be a 2" thread-on flange

 

[BigInch]

As opposed to a 2" tap in a 4" blind flange

 

[Shmulik]

Friends, the description in the question is misleading.

Making 2" NPT thread on 4" Blind flange is prohibited by ASME B16.5 (regardless to flange class)
Please see in Table 6 for reducing flanges, at columns 3+4: the smallest size of reducing outlet requiring Hub Flange for NPS 4" is 1.1/2"

As you all very well know, Blind Type Flange IS NOT Hub Flange, so, 2" outlet on 4" Blind is prohibited.

What you need here is: Threaded Reducing Flange 4"X2" #150 RF. As per ASME B16.5
It is hubbed flange, as it appears at bimr's post above.

 

[bimr]

Yes, you are correct Big Inch. It is a blind flange that is drilled and tapped.

Shmulik is correct as well, but the poster has not said that this is a code piping application.

While the Blind flange is used to cap off the end of a pipeline or a future branch connection it is also used for other purposes. It can be drilled and tapped for a threaded reducing flange or machined out for a Slip-On reducing flange. The reduced opening can be either on-center or eccentric.

Picture of blind flange.

Here is a picture showing a pipe screwed into a drilled and tapped blind flange.

 

[IFRs]

It is not unusual to have a drain in a blind flange at the end of the piperack.

 

[XL83NL]

Apart from the

Threaded Reducing Flange 4"X2" #150 RF. As per ASME B16.5

as mentioned by Shmulik, you can also order a
[ul]
[li]4" Hig Hub Blind Flange[/li]
[li]Class 150[/li]
[li]2" NPT hole[/li]
[/ul]

A reducing may be more expensive in some cases, although I think that in this case the flange from which the result is machined (i.e. either the Hig Hub Blind Flange, or the Reducing threaded flange) has the same starting point/geometry.