What is an orifice flange? And Dimensions

What is an orifice flange?

The Orifice Flange is used to measure how much product is flowing through the piping system. When the Orifice Plate is put in place, the flow is restricted. This makes a difference in pressure, which is used to measure how fast liquids, steam,or gasses are moving. The Orifice Plate is a thin plate with a hole in the middle. The size of the hole is based on the flow rate you want.

The traditional orifice flange assembly is made up of two flanges, an orifice plate, bolts, nuts, gaskets, jacking screws, and plugs. Jacking screws make it easy to get the primary flow element out of the way.

Orifice flanges are available in all ASTM forged grades (ASTM A105, ASTM A350, ASTM A694, and ASTM a182 for carbon, alloy, and stainless steel flanges, respectively), dimensions (combinations of nominal sizes and pressure ratings), and shapes (socket weld, threaded, or weld neck) (WN is the most used).

ORIFICE FLANGE MATERIAL GRADE AND FACINGS

Orifice Flange assemblies are available in all ASTM material grades and fall under ASME B16.36. They can have either a Raised Face or a Ring Type Joint facing. They aren’t made in 150# rated Flanges because they aren’t thick enough to let the pressure taps be drilled. Instead, they are made in 300#, 600#, 900#, 1500#, and 2500# Classes.

ORIFICE UNIONS

The Orifice Flange assemblies are made up of two Flanges, bolts, nuts, gaskets, jack screws, and plugs. The jack screws are used to put the Orifice Plate in place or take it out. Orifice Unions are the names for these groups of parts. To avoid turbulence at the Orifice Plate, the Orifice Flanges are installed in a straight run of pipe with ten pipe diameters upstream of the Orifice Plate and five pipe diameters downstream. The American Gas Association says this is the case.

Orifice flanges are a type of flange that are mostly used in the industrial world to measure how fast liquids, gases, or steam move through pipelines. They are often used in the oil and gas, chemical, and water treatment industries, where measuring flow accurately is important for the best results.

In this article, we’ll talk about what an orifice flange is, how it works, what it can be used for, and why it’s important for industrial operations to run smoothly.

Understanding Orifice Flange

An orifice flange is a special kind of flange that is put into a pipeline system to measure how fast a fluid is moving through it. It is made up of a plate with a hole in the middle and two flanges on either side. The orifice plate makes a drop in pressure that can be used to measure how fast the fluid is moving.

There are many different sizes, types of materials, and pressure ratings for orifice flanges. The flow rate and the size of the pipe are used to figure out the size of the orifice. The type of fluid going through the pipeline determines what kind of material is used to make the orifice flange. For instance, if the fluid is corrosive, the orifice flange must be made of a material that doesn’t corrode, like stainless steel.

What is the purpose of an orifice flange?

A pressure drop in the pipeline system is what makes an orifice flange work. As the fluid moves through the orifice plate, its speed goes up while the pressure goes down. The pressure drop is related to the flow rate, and it can be measured with pressure gauges on either side of the orifice plate.

Bernoulli’s equation can be used to figure out how fast the fluid is moving based on the difference in pressure across the orifice plate. The equation shows how the flow of a fluid is related to the drop in pressure across an orifice plate.

How Orifice Flanges Are Used

Most of the time, orifice flanges are used in pipeline systems to measure flow. They are used in many different fields, such as:

Oil and gas: Orifice flanges are used to measure how fast crude oil, natural gas, and other petroleum products flow.
Orifice flanges are used to measure the flow rate of chemicals and corrosive liquids in the chemical industry.
Orifice flanges are used in water treatment plants to measure the flow rate of water and waste water.

In addition to measuring flow, orifice flanges are also used in systems that lower pressure. In these systems, they help lower the pressure of the fluid flowing through the pipeline.

Orifice Flanges Have Some Pros

Orifice flanges have a number of advantages, such as:

– Accurate flow measurement: Orifice flanges make it possible to measure flow accurately, which is important for industrial operations to run smoothly.

– Cost-effective: Orifice flanges aren’t as expensive as flow meters or other devices used to measure flow.

– Easy to set up: Orifice flanges are easy to set up and don’t need much maintenance.

How to Install an Orifice Flange

To measure flow accurately, orifice flanges must be installed correctly. The orifice plate needs to be in the middle of the pipeline, and the flanges need to be tightened to the right torque. To measure pressure correctly, the pressure taps on either side of the orifice plate must also be installed correctly.

Flange dimensions 150 refer to the size of the flange as per ANSI/ASME standards. This flange size is commonly used in various industrial applications, including petrochemical, chemical, and oil and gas industries.

The dimensions of flange 150 are as follows:

-The nominal size of the flange is 1.5 inches (38.1 mm)

-The outer diameter of the flange is 5.0 inches (127 mm)

-The bolt circle diameter is 3.88 inches (98.6 mm)

-The number of bolt holes is four

-The diameter of bolt holes is 0.62 inches (15.7 mm)

-The thickness of the flange is 0.88 inches (22.4 mm)

-It is important to note that these dimensions are specific to flange 150 and may vary for other flange sizes.

The flange 150 is designed to withstand high pressure and temperature, making it suitable for various industrial applications. It is typically made of materials such as carbon steel, stainless steel, and alloy steel, depending on the specific application requirements.

WELD NECK RF, CLASS 300

NPS	A	R	O	T	H	X	Tg
1	33.4	50.8	125	36.6	81	54	6.4
1½	48.3	73	155	36.6	84	70	6.4
2	60.3	92.1	165	36.6	84	84	6.4
2½	73	104.8	190	36.6	87	100	6.4
3	88.9	127	210	36.6	87	117	9.5
4	114.3	157.2	255	36.6	90	146	12.7
6	168.3	215.9	320	36.6	98	206	12.7
8	219.1	269.9	380	39.7	110	260	12.7
10	273	323.8	445	46.1	116	321	12.7
12	323.8	381	520	49.3	129	375	12.7
14	355.6	412.8	585	52.4	141	425	12.7
16	406.4	469.9	650	55.6	144	483	12.7
18	457	533.4	710	58.8	157	533	12.7
20	508	584.2	775	62	160	587	12.7
24	610	692.2	915	68.3	167	702	12.7

NPS	Bolt Diameter	# Bolts	Bolt holes diameter	Bolts Diameter	Bolts length mm.
1	88.9	4	11/16	5/8	125
1½	114.3	4	13/16	3/4	135
2	127	8	11/16	5/8	125
2½	149.2	8	13/16	3/4	135
3	168.3	8	13/16	3/4	135
4	200	8	13/16	3/4	135
6	269.9	12	7/8	3/4	135
8	330.2	12	1	7/8	145
10	387.4	16	1 1/8	1	165
12	450.8	16	1¼	1 1/8	180
14	514.4	20	1¼	1 1/8	185
16	571.5	20	1 3/8	1¼	195
18	628.6	24	1 3/8	1¼	205
20	685.8	24	1 3/8	1¼	215
24	812.8	24	1 3/8	1½	240

WELD NECK RF, CLASS 600

NPS	A	R	O	T	H	X	Tg
1	33.5	50.8	125	36.6	81	54	6.4
1½	48.3	73	155	36.6	84	70	6.4
2	60.3	92.1	165	36.6	84	84	6.4
2½	73	104.8	190	36.6	87	100	6.4
3	88.9	127	210	36.6	87	117	9.5
4	114.3	157.2	275	38.1	102	152	12.7
6	168.3	215.9	355	47.7	117	222	12.7
8	219.1	269.9	420	55.6	133	273	12.7
10	273	323.8	510	63.5	152	343	12.7
12	323.8	381	560	66.7	156	400	12.7
14	355.6	412.8	605	69.9	165	432	12.7
16	406.4	469.9	685	76.2	178	495	12.7
18	457.2	533.4	745	82.6	184	546	12.7
20	508	584.2	815	88.9	190	610	12.7
24	609.6	692.2	940	101.6	203	718	12.7

NPS	BOLT CIRCLE DIAM.	BOLTS #	HOLES DIAM.	BOLTS DIAMETER	BOLTS LENGTH
1	88.9	4	11/16	5/8	125
1½	114.3	4	13/16	3/4	135
2	127	8	11/16	5/8	125
2½	149.2	8	13/16	3/4	135
3	168.3	8	13/16	3/4	135
4	215.9	8	1	7/8	150
6	292.1	12	1 1/8	1	180
8	349.2	12	1¼	1 1/8	195
10	431.8	16	1 3/8	1¼	220
12	489	20	1 3/8	1¼	230
14	527	20	1½	1 3/8	240
16	603.2	20	1 5/8	1½	260
18	654	20	1 3/4	1 5/8	280
20	723.9	24	1 3/4	1 5/8	300
24	838.2	24	2	1 5/8	335

COMMENTS: Height of Raised Face (RF) in CLASS 600 is 2 mm at NPS 1 – NPS 3, and 7 mm at NPS 4 – NPS 24.

WELD NECK RF, CLASS 900

NPS	R	O	T	H	X	A	Tg
1	50.8	125	36.6	81	54	33.5	6.4
1½	73	155	36.6	84	70	48.3	6.4
2	92.1	165	36.6	84	84	60.3	6.4
2½	104.8	190	36.6	87	100	73	6.4
3	127	240	38.1	102	127	88.9	9.5
4	157.2	290	44.5	114	159	114.3	12.7
6	215.9	380	55.6	140	235	168.3	12.7
8	269.9	470	63.5	162	298	219.1	12.7
10	323.8	545	69.9	184	368	273	12.7
12	381	610	79.4	200	419	323.8	12.7
14	412.8	640	85.8	213	451	355.6	12.7
16	469.9	705	88.9	216	508	406.4	12.7
18	533.4	785	101.6	229	565	457.2	12.7
20	584.2	855	108	248	622	508	12.7
24	692.2	1040	139.7	292	749	609.6	12.7

NPS	BOLT CIRCLE DIAM.	BOLTS #	HOLES DIAM.	BOLTS DIAMETER	BOLTS LENGTH
1	88.9	4	11/16	5/8	125
1½	114.3	4	13/16	3/4	135
2	127	8	11/16	5/8	125
2½	149.2	8	13/16	3/4	135
3	190.5	8	1	7/8	150
4	235	8	1¼	1 1/8	180
6	317.5	12	1¼	1 1/8	195
8	393.7	12	1½	1 3/8	230
10	469.9	16	1½	1 3/8	240
12	533.4	20	1½	1 3/8	260
14	558.8	20	1 5/8	1½	280
16	616	20	1 3/4	1 5/8	290
18	685.8	20	2	1 7/8	330
20	749.3	20	2 1/8	2	355
24	901.7	20	2 1/8	2½	445

WELD NECK RF, CLASS 1500

NPS	R	O	T	H	X	A	Tg
1	50.8	150	38.1	83	52	33.5	6.4
1½	73	180	38.1	89	70	48.3	6.4
2	92.1	215	38.1	102	105	60.3	6.4
2½	104.8	245	41.3	105	124	73	6.4
3	127	265	47.7	117	133	88.9	9.5
4	157.2	310	54	124	162	114.3	12.7
6	215.9	395	82.6	171	229	168.3	12.7
8	269.9	485	92.1	213	292	219.1	12.7
10	323.8	585	108	254	368	273	12.7
12	381	675	123.9	283	451	323.8	12.7
14	412.8	750	133.4	298	495	355.6	12.7
16	469.9	825	146.1	311	552	406.4	12.7
18	533.4	915	162	327	597	457.2	12.7
20	584.2	985	177.8	356	641	508	12.7
24	692.2	1170	203.2	406	762	609.6	12.7

NPS	BOLT CIRCLE DIAM.	BOLTS #	HOLES DIAM.	BOLTS DIAMETER	BOLTS LENGTH
1	101.6	4	1	7/8	150
1½	123.8	4	1 1/8	1¼	160
2	165.1	8	1	7/8	150
2½	190.5	8	1 1/8	1	165
3	203.2	8	1¼	1 1/8	185
4	241.3	8	1 3/8	1¼	205
6	317.5	12	1½	1 3/8	265
8	393.7	12	1 3/4	1 5/8	300
10	482.6	12	2	1 7/8	345
12	571.6	16	2 1/8	2	380
14	635	16	2 3/8	2¼	415
16	704.8	16	2 5/8	2½	450
18	774.7	16	2 7/8	2 3/4	500
20	831.8	16	3 1/8	3	545
24	990.6	16	3 5/8	3½	620

WELD NECK RF, CLASS 2500

NPS	R	O	T	H	X	A	Tg
1	50.8	160	38.1	92	57	33.5	6.4
1½	73	205	44.5	111	79	48.3	6.4
2	92.1	235	50.8	127	95	60.3	6.4
2½	104.8	265	57.2	143	114	73	6.4
3	127	305	66.7	168	133	88.9	9.5
4	157.2	355	76.2	190	165	114.3	12.7
6	215.9	485	108	273	235	168.3	12.7
8	269.9	550	127	318	305	219.1	12.7
10	323.8	675	165.1	419	375	273	12.7
12	381	760	184.2	464	441	323.8	12.7

NPS	BOLT CIRCLE DIAM.	BOLTS #	HOLES DIAM.	BOLTS DIAMETER	BOLTS LENGTH
1	108	4	1	7/8	150
1½	146	4	1¼	1 1/8	180
2	171.4	8	1 1/8	1	185
2½	196.8	8	1¼	1 1/8	205
3	228.6	8	1 3/8	1¼	230
4	273	8	1 5/8	1½	260
6	368.3	8	2 1/8	2	350
8	438.2	12	2 1/8	2	385
10	539.8	12	2 5/8	2½	490
12	619.1	12	2 7/8	2 3/4	540