These
plates are used to drop line pressure.
The bore for a given pressure drop
is determined by means of the pipe
tap calculation where the desired
pressure drop for the line is the
differential pressure in the calculation.
When the fluid is a gas or vapor,
the maximum pressure drop which can
be made with a single orifice plate
without throttling the flow is approximately
1/2 the absolute upstream pressure.
If a pressure drop greater than 50%
of the upstream pressure is required,
it may be accomplished with multiple
restriction bored orifice plates spaced
10 diameters apart. Each will drop
the pressure less than half its upstream
pressure.
Plate
O.D. , inches
Dimensions
Pipe
Size
Rating,
lb
L
Inches
N
Inches
K
Inches
150#
300#
400#
600#
900#
1500#
2500#
1/2 "
1
7/8"
2
1/8"
2
1/8"
2
1/8"
2
1/2"
2
1/2"
2
3/4"
4"
1"
1/4"
3/4"
2
1/4"
2
5/8"
2
5/8"
2
5/8"
2
3/4"
2
3/4"
3"
4"
1"
1/4"
1"
2
5/8"
2
7/8"
2
7/8"
2
7/8"
3
1/8"
3
1/8"
3
3/8"
4"
1"
1/4"
1 1/4"
3"
3
1/4"
3
1/4"
3
1/4"
3
1/2"
3
1/2"
4
1/8"
4"
1"
1/4"
1 1/2"
3
3/8"
3
3/4"
3
3/4"
3
3/4"
3
7/8"
3
7/8"
4
5/8"
4"
1"
1/4"
2"
4
1/8 "
4
3/8 "
4
3/8 "
4
3/8 "
5
5/8 "
5
5/8 "
5
3/4"
4"
1"
1/4"
2
1/2"
4
7/8 "
5
1/8"
5
1/8"
5
1/8"
6
1/2"
6
1/2"
6
5/8"
4"
1 1/4"
3/8"
3"
5
3/8"
5
7/8 "
5
7/8 "
5
7/8 "
6
5/8 "
6
7/8 "
7
3/4"
4"
1 1/4"
3/8"
4"
6
7/8 "
7
1/8 "
7"
7
5/8 "
8
1/8 "
8
1/4"
9
1/4"
4"
1 1/4"
3/8"
5"
7
3/4 "
8
1/2 "
8
3/8"
9
1/2 "
9
3/4"
10"
11"
5"
1 1/2"
3/8"
6"
8
3/4 "
9
7/8 "
9
3/4"
10
1/2"
11
3/8 "
11
1/8 "
12
1/2"
5"
1 1/2"
3/8"
8"
11"
12
1/8 "
12
12
5/8 "
14
1/8"
13
7/8"
15
1/4"
5"
1 1/2"
3/8"
10"
13
3/8 "
14
1/4 "
14
1/8"
15
3/4 "
17
1/8 "
17
1/8 "
18
3/4"
6"
1 1/2"
3/8"
12"
16
1/8"
16
5/8 "
16
1/2"
18"
19
5/8 "
20
1/2"
21
5/8"
6"
1 1/2"
3/8"
14"
17
3/4 "
19
1/8 "
19
19
3/8 "
20
1/2"
22
3/4"
--
6"
1 1/2"
1/2"
16 "
20
1/4 "
21
1/4 "
21
1/8"
22
1/4 "
22
5/8"
25
1/4"
--
6"
1 1/2"
1/2"
*
Hastelloy C is a registered trademark of Delloro
Stellite Co.
** Carp. 20
is a registered trademark of Carpenter Steel Co.
