0:30
say that for FL standards you don't
0:32
require any logic. Let's put that to the
0:35
test. So for example we are having an
0:37
SPB 16.36 standard which is usually used
0:40
for orifice meters. So will you be using
0:42
orifice flow meter for integral or for
0:45
restriction RFI the same standard? The
0:47
answer is a big no. Why? Let's look at
0:50
the logic behind it. Basically the asme
0:53
standard is divided into four FL
0:55
standards which is 16.5 47 36 and 34.
1:00
The basic and the most simple two
1:02
standards are 16.5 and 16.47. Then we'll
1:05
get to the complex ones like 16.36 and
1:08
16.34. Now 16.5 is basically from NPS/2
1:12
in to 24 in. And 16.47 is between 26 in
1:16
to 16 in of NPS. Now 16.47 is further
1:20
divided into series A flange and series
1:23
B flanges. Series A flanges and series B
1:26
flanges are not compatible with each
1:29
other. For example, if you have 150
1:31
rating flange, then series A would have
1:33
28 volts while series B would have 44
1:36
volts. So, we need to be cautious about
1:38
this fact. And also, if you want to know
1:40
when to use what, so usually for
1:42
critical lines, you use series A and for
1:44
non-critical lines like utility, water,
1:47
etc., you would use series B flanges.
1:49
Now, let's look into the most
1:50
interesting part of it, which is asb
1:52
16.36. Why do we have this standard? Now
1:55
SPB 16.36 if you see it is usually used
1:59
for orifice meter assemblies and in
2:01
orifice flanges are a little different
2:02
from the regular flanges. Why? Because
2:05
if you see that the water which is going
2:07
to flow any liquid has to be measured
2:09
when a DP is created. So these flange
2:12
have to be actually drilled and when you
2:14
drill a flange you reduce its mechanical
2:17
power or mechanical integrity because
2:19
you're putting a hole through it. So
2:21
because of that case 150 ratings are not
2:23
part of 16.36. It directly starts from
2:26
300 lb rating. So such flanges are
2:29
specially designed for such holes being
2:31
drilled into them. However, if you
2:33
notice for an integral orifice assembly,
2:35
these are part of vendor scope and what
2:38
are the end connections that we get
2:39
these. So now here there is no hole
2:41
which is drilled into the end
2:42
connections. So there is no need for asb
2:45
16.36 to be specified for integral
2:48
orifice meters. Similarly, if you look
2:50
at restriction RFIS, restriction RFI
2:53
just put a restriction in the line of
2:54
flow and thus there is no DP that has to
2:57
be measured. So the flanges don't have
2:59
to be drilled and hence we don't have to
3:02
use asb 16.36 even for restriction
3:05
orises. That is why it's very important
3:07
to know the logic. If you're passionate
3:09
about instrumentation then every
3:11
Saturday I produce a new video and I
3:14
hope you would find these videos
3:15
valuable. Let's get to the next part of
3:17
the flange stand which is ASME 16.34.
3:20
Now this is why is this delude
3:22
especially for valves. We don't have to
3:23
drill any holes into valves. Right now
3:26
know that something called as MSS which
3:28
stands for manufacturers standardization
3:30
society of valves and fittings. Now
3:33
these standards and the ASP standards
3:35
had to be collaborated together because
3:37
there were lot of people which were
3:39
following MSS standards some were
3:40
following as standards. So then asp.34
3:44
basically combines 16.5 standard which
3:47
is called as the standard flange class.
3:51
which is the special flange class and
3:53
the third one is MSSB 84 which stands
3:56
for limited flange class. So basically
3:58
as 16.34 tried to combine all these
4:01
standards together under one umbrella.
4:03
For example, if you have a 2 in 300lb
4:05
flange, you could say it's called a
4:07
special if you put SPL in the end or you
4:09
could put limited as Ltd. But remember
4:12
that usually you always go for the
4:14
standard class even though the special
4:17
and the limited class in 300 rating it
4:19
can occupy even more PT ratings but
4:21
because of the stringent requirements of
4:24
testing people usually prefer to stick
