Blind Flanges

What are Blind Flanges?

Blind flanges (also called a ‘closure plate flanges’) are pipe flanges that are used to seal off the end of a piping system. They are typically used in situations where the end of the pipe needs to be sealed off or blocked, such as when making a connection to a valve or pressure vessel. Blind flanges are solid and do not have a bore, or hole, in the center like other types of flanges. This makes them useful for blocking off the flow of fluid or gas in a piping system. Because they do not have a bore, BL flanges are not used for piping that carries fluids or gases. Instead, they are used for applications such as pressure testing or as a mechanism to access the inside of a pipe for maintenance or cleaning. They are typically used in high-pressure applications and are often rated to withstand pressures of up to several thousand pounds per square inch.

Standard Specication For Blind Flanges

• Dimensions: ANSI B16.5, ANSI B16.47 Series A & B, MSS SP44, ASA, API-605, AWWA, Custom Drawings
• Size : 1/2″ (15 NB) to 48″ (1200NB)
• Class : 150 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS, 2500 LBS, DIN Standard ND-6,10, 16, 25, 40 Etc.
• DIN : DIN2527, DIN2566, DIN2573, DIN2576, DIN2641, DIN2642, DIN2655, DIN2656, DIN2627, DIN2628, DIN2629,
• DIN 2631, DIN2632, DIN2633, DIN2634, DIN2635, DIN2636,DIN2637, DIN2638, DIN2673
• BS : BS4504 , BS4504, BS1560, BS10
• Flange Face Type : Flate Face (FF), Raised Face (RF), Ring Type Joint (RTJ)

Advantages and disadvantage of Blind Flanges

Some advantages of blind flanges include their ability to be easily installed and removed, as well as their versatility in terms of being able to connect to different types of pipes. Another advantage of blind flanges is that they can be easily sealed to prevent the passage of fluid or gas. One potential disadvantage of blind flanges is that they are not able to be used for operations that require the passage of fluid or gas through the end of the piping system. Additionally, blind flanges may not be suitable for applications that require high levels of pressure, as they may not be able to withstand the pressure without leaking or bursting.

What are the different types of sealing faces used on blind flanges?

Sealing faces are an important part of a BL flange, as they help to create a seal between the flange and the mating surface. The type of sealing face used on a blind flange will depend on the specific application and the type of fluid or gas being transported.

• Flat face blind flanges are the most common type of sealing face, and are typically used for low-pressure applications. The flat face flange has a flat sealing surface, with no raised or recessed areas.
• Raised face blind flanges have a small raised area around the bolt hole, which helps to create a better seal. They are often used in higher-pressure applications.
• Male and female face blind flanges are also used in higher-pressure applications. Male face flanges have a raised area around the bolt hole, while female face flanges have a recessed area.
• Right joint face blind flanges are used in applications where the flange will be bolted to a flat surface. They have a flat sealing surface with no raised or recessed areas.
• Tongue and groove face blind flanges are used in applications where the flange will be bolted to a pipe or other cylindrical surface. They have a tongue-and-groove style sealing surface, which helps to create a better seal.

In general, the type of sealing face used on a blind flange will depend on the specific application and the pressure and temperature of the fluid or gas being transported. It’s important to choose the right type of sealing face to ensure that the flange provides a reliable and effective seal.

Material of Blind Flanges

Blind Flanges are typically made from cast or forged carbon steel, stainless steel, or other alloy materials. The specific material used will depend on the application and the design specifications of the flange. It is important to choose the right material for a flange to ensure that it is strong and durable enough to handle the pressure and temperature conditions it will be subjected to in service.

Carbon Steel Blind Flange	ASTM/ASME A/SA105 A/SA105N & A/SA216-WCB, DIN 1.0402, DIN 1.0460, DIN 1.0619, Die Steel, ASTM A105 / ASME SA105, A105N, ASTM A350 LF2 / ASME SA350, High Yield CS ASTM A694 / A694 (F52 F56 F60 F65 F70 F80)
Stainless Steel Blind Flange	ASTM/ASME A/SA182 F304, F304L, F316, F316L, ASTM/ASME A/SA351 CF8, CF3, CF8M, CF3M, DIN 1.4301, DIN 1.4306, DIN 1.4401, DIN 1.4404, DIN 1.4308, DIN 1.4408, DIN 1.4306, DIN 1.4409
Alloy Steel Blind Flange	ASTM A182 / ASME SA182 F5, F9, F11, F12, F22, F91
Titanium Blind Flange	ASTM B381 / ASME SB381, Titanium Gr. 1, Titanium Gr. 2, Titanium Gr. 4, Titanium Gr. 5, Titanium Gr. 7 ASTM R50250/GR.1 | R50400/GR.2 | R50550/GR.3 | R50700/GR.4 | GR.6 |R52400/GR.7 | R53400/GR.12 | R56320/GR.9 |R56400/GR.5
Copper Blind Flange	T1, T2, C10100, C10200, C10300, C10400, C10500, C10700, C10800, C10910,C10920, TP1, TP2, C10930, C11000, C11300, C11400, C11500, C11600, C12000,C12200, C12300, TU1, TU2, C12500, C14200, C14420, C14500, C14510, C14520, C14530, C17200, C19200, C21000, C23000, C26000, C27000, C27400, C28000, C33000, C33200, C37000, C44300, C44400, C44500, C60800, C63020, C68700, C70400, C70600, C70620, C71000, C71500, C71520, C71640, etc
Copper Nickel Blind Flange	ASTM / ASME SB 61 / 62 / 151 / 152, Copper Nickel 90/10 (C70600 ), Cupro Nickel 70/30 (C71500), UNS C71640
Brass Blind Flange	3602 / 2604 / H59 / H62 / etc.
Inconel Blind Flange	ASTM B564 / ASME SB564, Inconel 600, 601, 625, 718, 783, 690, x750
Hastelloy Blind Flange	ASTM B564 / ASME SB564, Hastelloy C276 (UNS N10276), C22 (UNS N06022), C4, C2000, B2, B3, X
Monel Blind Flange	ASTM B564 / ASME SB564, Monel 400 (UNS No. N04400), Monel 500 (UNS No. N05500)
Alloy 20 Blind Flange	ASTM B462 / ASME SB462, Carpenter® 20 Alloy, Alloy 20Cb-3
Aluminium Blind Flange	5052 /6061/ 6063 / 2017 / 7075 / etc.
Nickel Blind Flange	ASTM B564 / ASME SB564, Nickel 200, Nickel 201, Nickel 205, Nickel 205LC
Duplex Blind Flange	S31803 / S32205 A182 Gr F51 / F52 / F53 / F54 / F55 / F57 / F59 / F60 / F61
Super Duplex Blind Flange	S32750 / S32760 A182 Gr F51 / F52 / F53 / F54 / F55 / F57 / F59 / F60 / F61
Incoloy Blind Flange	ASTM B564 / ASME SB564, Incoloy 800, 800H, 800HT (UNS N08800), 825 (UNS N08825), 925
254 Smo Blind Flange	ASTM A182 / ASME SA182, SMO 254/6Mo, UNS S31254, DIN 1.4547
Nimonic Blind Flange	Nimonic 75, Nimonic 80A, Nimonic 90
Other Blind Flange material	Tin bronze, Alumunum bronze, Lead bronze

Size of Blind Flanges

The size of a blind flange is determined by the size of the opening it is used to seal. For example, a blind flange with a 4-inch diameter would be used to seal a 4-inch pipe or opening. The size of the flange itself will typically be slightly larger than the opening it is used to seal, to ensure a tight fit.

Dimensions of Blind Flanges

The dimensions of a blind flange will depend on the specific application and the size of the pipe or fitting it is being used with. In general, the flange will have a diameter that is equal to the outer diameter of the pipe, and it will have bolt holes spaced around the circumference of the flange to allow it to be securely attached to the pipe or fitting. The thickness of the flange will also vary depending on the pressure rating and the material it is made from.

Dimensions of ASME B16.5 Blind Flange

 

Class 150 Blind Flange Dimensions

Class 600 Blind Flange Dimensions

Pipe Normal Diam.		O.D. Flange	Thk. Of Flange Min	Diam.ofHub	Diam.of BoltCircle	Diam.of BoltHoles	Numberof Bolts	Diam. ofBolts(inch)	Approx. Weight
inch	dn	O	C	X	BC	BH	BN	BD	KG/PCS	LB/PCS
1/2	15	120.7	22.4	38.1	82.6	22.4	4	3/4	1.9	4.2
3/4	20	130	25.4	44.5	88.9	22.4	4	3/4	2.7	6
1	25	149.4	28.4	52.3	101.6	25.4	4	7/8	3.7	8.1
1-1/4	32	158.8	28.4	63.5	111.3	25.4	4	7/8	4.3	9.5
1-1/2	40	177.8	31.8	69.9	124	28.4	4	1	5.9	13
2	50	215.9	38.1	104.6	165.1	25.4	8	7/8	11.3	24.9
2-1/2	65	244.3	41.1	124	190.5	28.4	8	1	16	35.2
3	80	266.7	47.8	133.4	190.5	25.4	8	7/8	19.5	43
4	100	311.2	53.8	162.1	235	31.8	8	1 1/8	33	72.8
5	125	374.7	73.2	196.9	279.4	35.1	8	1 1/4	60	132
6	150	393.7	82.6	228.6	317.5	31.8	12	1 1/8	75	165
8	200	482.6	91.9	292.1	393.7	38.1	12	1 3/8	125	275
10	250	584.2	108	368.3	469.9	38.1	16	1 3/8	215	474
12	300	673.1	124	450.9	533.4	38.1	20	1 3/8	316	697
14	350	749.3	133.4	495.3	558.8	41.1	20	1 1/2
16	400	825.5	146.1	552.5	616	44.5	20	1 5/8
18	450	914.4	162.1	596.9	685.8	50.8	20	1 7/8
20	500	984.3	177.8	641.4	749.3	53.8	20	2
24	600	1168.4	203.2	762	901.7	66.5	20	2 1/2

Note:

• 1) Blind Flanges may be made with the same hub as that used for Slip-on Flanges or without hub.

ASME/ANSI B16.5 2500lb Blind Flange

Pipe Normal Diam.		O.D. Flange	Thk. Of Flange Min	Diam.of BoltCircle	Diam.of BoltHoles	Numberof Bolts	Diam. ofBolts(inch)	KG	LB
inch	dn	O	C	BC	BH	BN	BD
1/2	15	133.4	30.2	88.9	22.4	4	3/4	3	7
3/4	20	139.7	31.8	95.3	22.4	4	3/4	4.5	10
1	25	158.8	35.1	108	25.4	4	7/8	5	12
1-1/4	32	184.2	38.1	130	28.4	4	1	8	18
1-1/2	40	203.2	44.5	146.1	31.8	4	1 1/8	11	25
2	50	235	50.8	171.5	28.4	8	1	17	38
2-1/2	65	266.7	57.2	196.9	31.8	8	1 1/8	25	55
3	80	304.8	66.5	228.6	35.1	8	1 1/4	39	86
4	100	355.6	76.2	273.1	41.1	8	1 1/2	60	133
5	125	419.1	91.9	323.9	47.8	8	1 3/4	101	223
6	150	482.6	108	368.3	53.8	8	2	156	345
8	200	552.5	127	438.2	53.8	12	2	242	533
10	250	673.1	165.1	539.8	66.5	12	2 1/2	465	1023
12	300	762	184.2	619.3	73.2	12	2 3/4	665	1463

Note:

• 1) Blind Flanges may be made with the same hub as that used for Slip-on Flanges or without hub.

Dimensional Tolerances of ASME B16.5 Blind Flanges

Outside Diameter ≤ 24 = 1.6 mm | > 24 = ± 3.2 mm	Inside Diameter   not applicable
Diameter of Contact Face 1.6 mm Raised Face = ± 0.8 mm 6.35 mm Raised Face, Tongue & Groove / Male-Female = ± 0.4 mm	Outside Diameter of Hub   ≤ 12 = + 2.4 mm / – 1.6 mm | ≥ 14 = ± 3.2 mm
Diameter of Counterbore not applicable	Drilling   Bolt Circle = 1.6 mm | Bolt Hole Spacing = ± 0.8 mm   Eccentricity of Bolt Circle with Respect to Facing   ≤ 2½ = 0.8 mm max. | ≥ 3 = 1.6 mm max.
Thickness ≤ 18 = + 3.2 mm / – 0 | ≥ 20 = + 4.8 mm / – 0	Length thru Hub   ≤ 18 = + 3.2 mm / – 0.8 mm | ≥ 20 = + 4.8 mm / – 1.6 mm

Notes

• 1. Dimensions are in millimeters unless otherwise indicated.
• 2. The length of the stud bolt does not include the height of the chamfers (points).

Dimensions of JIS Blind Flange

JIS 5K Blind Flange Dimensions

JIS 10K Blind Flange Dimensions

JIS 16K Blind Flange Dimensions

Blind Flange Weight & Blind Flange Pressure Ratings

Manufacturing process of Blind Flanges

Production process of forged blind flange

The manufacturing process for forged blind flanges typically involves the following steps: Cutting the raw materials to size: The first step in the manufacturing process is to cut the raw materials to the required size and shape. This typically involves cutting sheets of metal, such as carbon steel or stainless steel, using a cutting machine. Forming the flange: Once the raw materials have been cut to size, the next step is to form the flange. This typically involves using a die-stamping machine to shape the metal into the desired flange shape. Heat treating the flange: Once the flange has been welded, it must be heat treated to improve its strength and durability. This typically involves heating the flange to a high temperature and then rapidly cooling it to harden the metal. Machining the flange: After the flange has been heat treated, it must be machined to achieve the desired level of precision and to create the necessary bolt holes and other features. This typically involves using a lathe or other machining equipment to shape the flange to the required specifications. Drilling holes in the flange for bolts to connect it to other components. Cleaning and preparing the surface of the flange for finishing. Applying a protective coating such as paint or galvanization to protect the flange from corrosion. Testing the flange to ensure it meets the required specifications and tolerances. Packaging the flange for shipping or storage. These steps may vary slightly depending on the specific type of flange being manufactured and the requirements of the application it will be used in.

Production process of casting blind flange

Casting blind flanges requires several steps. First, metal (usually iron or steel) is melted in a furnace and then poured into a mold. Moulds are usually made of sand and have the shape of the required flange, including the hole in the center. Once the metal cools and solidifies, the mold breaks and the flange is removed. They are then cleaned, inspected, and frequently machined to achieve the required dimensions and finish. Finally, the flange is ready for use.

Production process of cutting blind flange

The production process of cutting a blind flange typically involves the following steps: The raw materials, such as steel plates, are cut to size and shape using a cutting machine, such as a plasma cutter or laser cutter. The cut pieces are then machined to the desired dimensions and tolerances using a variety of machine tools, such as lathes, mills, and drills. The flange is then heat treated to improve its strength and durability. This can involve heating the flange to a high temperature and then quenching it in oil or water. The flange is then sandblasted to remove any surface imperfections and to improve its surface finish. Any holes or bolt holes are then drilled or punched into the flange using specialized machines. The flange is then inspected for quality and conformity to specifications. If necessary, the flange may be coated with a protective coating to prevent corrosion and improve its appearance. The flange is then packaged and shipped to the customer.

Marking of Blind Flanges

Blind flanges are usually marked with the letter “B” to indicate their type and the pressure rating of the flange, such as “150LB” for a 150-pound pressure rating. The pressure rating of the flange is important because it determines the maximum pressure that the flange can safely handle. In addition to the pressure rating, blind flanges may also be marked with the material of construction, such as carbon steel or stainless steel, as well as any applicable industry standards or codes. This information can be found on the flange itself, often along the outer edge or around the center hole. The marking may be embossed or stamped into the metal, or it may be in the form of a label or tag attached to the flange.

Packing of Blind Flanges

Blind flanges are usually packed in cartons or wooden boxes. In order to prevent damage during transportation, the box can also be protected inside, such as using foam filler or other similar materials. It is important to ensure that the stainless steel flange will not be damaged during transportation to ensure that it can work as expected.

Inspection and Measurement of Blind Flanges

In order to ensure that the blind flange works normally, it is very important to check and measure the blind flange regularly to ensure that it is in good condition and meets the necessary specifications. To inspect blind flanges, visually inspect for any signs of damage or defects, such as cracks, dents, or corrosion. The flanges should also be checked for correct alignment and any signs of leakage. To measure the blind flange, check several different dimensions. The first is the outer diameter of the flange, that is, the distance at the widest part of the flange. The second is the inner diameter of the flange, that is, the distance through the flange opening. The third is the thickness of the flange, that is, the distance from the outer surface of the flange to the inner surface. Other dimensions that can be measured include the bolt hole diameter of the flange and the distance between the bolt holes. When measuring blind flanges, be sure to use appropriate tools and techniques to ensure accurate results. This may include the use of a tape measure, caliper or micrometer, depending on the required accuracy. Special measuring equipment, such as bore gauges or flange alignment tools, may also be required to accurately measure flange dimensions. The inspection and measurement of blind flange is an important step to ensure its correct installation and safe operation in the pipeline or pressure vessel system.

Application of Blind Flanges

Blind Flanges are known to deliver exceptional performance and are generally developed for meeting the demands. We oer a broad range of Flat Faced Blind Flanges through a worldwide network of stockkeeping branches. These Blind Flange is use in various industries like:

• Stainless Steel Blind Flanges uses in Oil and Gas Pipeline;
• Blind Raised Face Flanges uses in Chemical Industry;
• Alloy Steel BLRF Flanges uses in Plumbing;
• Flat Faced Blind Flanges uses in Heating;
• Blind Pipe Flanges uses in Water Supply Systems;
• Blind Forged Flanges uses in Power Plant;
• Blind Flanges uses in Paper & Pulp Industry;
• Blind Flange uses in General Purpose Applications;
• Steel Blind Flanges uses in Fabrication Industry;
• Blind Flange uses in Food Processing Industry;
• Blind Flanges uses in Structural Pipe.

Do I need a gasket for a blind flange?

Best practice is to use standard gaskets for these blind flanges. Blind flanges, like standard pipe flanges, can be either convex (RF) or flat (FF). If the flange is RF, we recommend using a standard ring gasket that is suitable for maintenance and/or testing.

How to purchase the correct blind flanges?

To purchase the right blind flange, you need to consider several factors. The following are the steps to follow. Determine the size and dimensions of the required blind flange. Measure the diameter of the pipe or equipment to which the blind flange will be connected and record the thickness of the blind flange. Select the material to be used for the blind flange. Common materials used for blind flanges include carbon steel, stainless steel and cast iron. Consider the pressure rating of the blind flange. The pressure rating will determine the maximum pressure that the blind flange can safely handle. Determine the type of connection required. Blind flanges can be bolted or welded to the pipe or equipment. Consider the intended use of the blind flange. If the blind flange will be used in a high temperature or corrosive environment, you may need to select a material that can withstand these conditions. With these factors in mind, you can then contact the supplier or manufacturer to purchase the correct blind flange for your needs. It may also be helpful to consult with an engineer or other professional to ensure that you have selected the right blind flange for your application.

How to select blind flanges manufacturer?

When selecting a blind flange manufacturer, there are several key factors to consider. Some of the most important factors to consider are the manufacturer’s experience and reputation, the quality of the product, and the ability to meet your specific needs and requirements. Here are a few steps you can follow to help you find a reputable blind flange manufacturer. Start by doing some research to identify some potential manufacturers who have experience in producing blind flanges. You can do this by seeking advice from other industry professionals, or by searching online for manufacturers who specialize in these products. Once you have a shortlist of potential manufacturers, contact each one to find out about their experience and capabilities. Ask about their past projects and the types of blind flanges they have produced in the past, and ask about their quality control processes to ensure their products meet industry standards. Request quotes from each manufacturer and compares prices, lead times, and other important factors to help you make an informed decision. Be sure to ask about any other services they offer, such as custom design and engineering support. It’s important to verify each manufacturer’s reputation before making a final decision. You can do this by reading online reviews, asking for testimonials from other customers, and checking to see if the manufacturer is registered with any industry associations or if they have received any certifications. Once you have gathered all the necessary information, carefully evaluate all factors to determine which manufacturer is best for your needs. Choose a manufacturer with a proven track record of producing high-quality products that can meet your specific requirements.

Export Country For Blind Plate Flanges

MIDDLE EAST	AFRICA	NORTH AMERICA	EUROPE	ASIA	SOUTH AMERICA
Saudi Arabia	Nigeria	Usa	Russia	India	Argentina
Iran	Algeria	Canada	Norway	Singapore	Bolivia
Iraq	Angola	Mexico	Germany	Malaysia	Brazil
Uae	South Africa	Panama	France	Indonesia	Chile
Qatar	Libya	Costa Rica	Italy	Thailand	Venezuela
Bahrain	Egypt	Puerto Rica	Uk	Vietnam	Colombia
Oman	Sudan	Trinidad And Tobago	Spain	South Korea	Ecuador
Kuwait	Equatorial Guinea	Jamaica	Ukraine	Japan	Guyana
Turkey	The Republic Of Congo	Bahamas	Netherland	Sri Lanka	Paraguay
Yemen	Gabon	Denmark	Belgium	Maldives	Uruguay
Syria			Greece	Bangladesh
Jordan			Czech Republic	Mayanmar
Cyprus			Portugal	Taiwan
			Hungary	Cambodia
			Albania
			Austria
			Switzerland
			Slovakia
			Finland
			Ireland
			Croatia
			Slovenia
			Malta