Blind Flanges Manufacturer

What are Blind Flange?

A blind flange is a type of flange used in piping systems to seal the end of a pipe, valve, or vessel opening. Unlike other flanges, it has no hole in the center, making it essentially a solid disc. This design allows it to block the flow of fluids or gases in a pipeline and provides a secure closure point. Blind flanges are commonly used in industries such as oil and gas, chemical processing, water treatment, and power generation, where sealing off sections of a piping system is necessary for maintenance, testing, or safety purposes.

Blind flanges are manufactured in a variety of materials, including carbon steel, stainless steel, alloy steel, and duplex steel, depending on the operating environment and pressure requirements. They are designed according to international standards such as ANSI/ASME, DIN, and JIS, and come in different pressure ratings to handle low to extremely high-pressure systems. Their surfaces may be flat, raised, or designed for ring-type joint gaskets to ensure a tight seal with the connected piping or equipment.

The primary function of a blind flange is to provide a secure closure and access point in a piping system. It allows engineers to isolate sections of a pipeline for inspection, maintenance, or pressure testing without disrupting the entire system. By using blind flanges, systems can be safely tested for leaks and pressure integrity. Additionally, they are sometimes used in conjunction with bolts and gaskets to provide a leak-proof connection, making them a crucial component in industrial piping infrastructure.

Leading Blind Flanges Manufacturer - Shribhairav Forge

Standards & Specifications of Blind Flanges

Adhering to the latest global benchmarks as of 2025, Shribhairav Forge's blind flanges conform to rigorous standards that guarantee interoperability and safety. Our production aligns with ASME B16.5 for nominal pipe sizes up to 24", extending to B16.47 Series A and B for larger diameters, ensuring compatibility across international projects.

Key Dimensional and Pressure Specifications

Dimensions: ANSI B16.5, ANSI B16.47 Series A & B, MSS SP44, ASA, API-605, AWWA, Custom Drawings

Size Range: 1/2" (15 NB) to 48" (1200NB)

Pressure Classes: 150 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS, 2500 LBS, DIN Standard ND-6,10, 16, 25, 40 Etc.

DIN Standards: DIN2527, DIN2566, DIN2573, DIN2576, DIN2641, DIN2642, DIN2655, DIN2656, DIN2627, DIN2628, DIN2629, DIN 2631, DIN2632, DIN2633, DIN2634, DIN2635, DIN2636,DIN2637, DIN2638, DIN2673

BS Standards: BS4504 , BS4504, BS1560, BS10

Flange Face Types: Flate Face (FF), Raised Face (RF), Ring Type Joint (RTJ)

These specs are validated through our in-house hydrostatic testing (up to 1.5x rated pressure) and dimensional verification using CMM (Coordinate Measuring Machines). For 2025 updates, we've incorporated ASME's revised tolerances for high-temperature deviations, ensuring slip on flanges perform flawlessly in fluctuating environments.

Specification	Class 150	Class 300	Class 600	Notes
Max Pressure (bar)	19.6	51.7	103.4	At 38°C ambient
Min Thickness (mm, 6″ size)	9.5	14.3	22.2	Per B16.5
Bolt Circle Dia. (mm, 4″)	114.3	152.4	190.5	8 holes standard
Weight (kg, 4″ CS)	1.6	2.3	4.1	Varies by material

Materials and Grades of Blind BLRF Flange

Material selection is the heart of any blind BLRF flange and its performance, and at Shribhairav Forge, we source only prime materials from LME-registered suppliers. Our portfolio spans ferrous and non-ferrous alloys, optimized for corrosion resistance (PREN values up to 40+), weldability, and environmental resilience.

Stainless Steel Blind BLRF Flange :

Grades of SS Blind Flange, SS BLRF FLANGE, BLIND FLANGE BLRTJ RING TYPE JOINT ALL are 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

Duplex Blind Flange :

Grades of Duplex Steel Blind Flange S31803 / S32205 A182 Gr F51 / F52 / F53 / F54 / F55 / F57 / F59 / F60 / F61

Super Duplex Blind Flange :

Grades of Super Duplex Steel Blind Flange are S32750 / S32760 A182 Gr F51 / F52 / F53 / F54 / F55 / F57 / F59 / F60 / F61

Alloy Steel Blind Flange :

ASTM A182 / ASME SA182 F5, F9, F11, F12, F22, F91

Carbon Steel Blind Flange :

CS BLRF Flanges and Blind BLRTJ Ring Type Joint 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)

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

DIMENSION OF BLRF BLIND RAISED FACE FLANGE ASNI B16.5

DIMENSION OF ANSI B16.5 FLANGES CLASS 150 LBS

Nominal Pipe Size	Nominal Pipe Size	Flange Dia O	Dia of Bolt Circle A	Dia of Bolt Holes D	No. of Holes	Thk of Flange C	Dia of Hub E	S/O & S/W Y	W/N Y	L/J Y	S/O & S/W B	L/J B	Dia of R/F R	Depth of Socket F
NB	INCH	MM	MM	MM	MM	MM	MM	LENGTH MM	LENGTH MM	LENGTH MM	BORE MM	BORE MM	MM	MM
15	1/2	88.9	60.3	15.9	4	11.1	30.2	15.9	47.6	15.9	22.3	22.9	34.9	9.5
20	3/4	98.4	69.8	15.9	4	12.7	38.1	15.9	52.4	15.9	27.7	28.2	42.9	11.1
25	1	107.9	79.4	15.9	4	14.3	49.2	17.5	55.6	17.5	34.5	35.0	50.8	12.7
32	1 1/4	117.5	88.9	15.9	4	15.9	58.7	20.6	57.1	20.6	43.2	43.7	63.5	14.3
40	1 1/2	127.0	98.4	15.9	4	17.5	65.1	22.2	61.9	22.2	49.5	50.0	73.0	15.9
50	2	152.4	120.6	19.0	4	19.0	77.8	25.4	63.5	25.4	62.0	62.5	92.1	17.5
65	2 1/2	177.8	139.7	19.0	4	22.2	90.5	28.6	69.8	28.6	74.7	75.4	104.8	19.0
80	3	190.5	152.4	19.0	4	23.8	107.9	30.2	69.8	30.2	90.7	91.4	127.0	20.6
100	4	228.6	190.5	19.0	8	23.8	134.9	33.3	76.2	33.3	116.1	116.8	157.2	23.8
125	5	254.0	215.9	22.2	8	23.8	163.5	36.5	88.9	36.5	143.8	144.5	185.7	23.8
150	6	279.4	241.3	22.2	8	25.4	192.1	39.7	88.9	39.7	170.7	171.4	215.9	27.0
200	8	342.9	298.4	22.2	8	28.6	246.1	44.4	101.6	44.4	221.5	222.2	269.9	31.7
250	10	406.4	361.9	25.4	12	30.2	304.8	49.2	101.6	49.2	276.3	277.4	323.8	33.3
300	12	482.6	431.8	25.4	12	31.8	365.1	55.6	114.3	55.6	327.1	328.2	381.0	39.7
350	14	533.4	476.2	28.6	12	34.9	400.0	57.1	127.0	79.4	359.1	360.2	412.7	41.3
400	16	596.9	539.7	28.6	16	36.5	457.2	63.5	127.0	87.3	410.5	411.2	469.9	44.4
450	18	635.0	577.8	31.7	16	39.7	504.8	68.3	139.7	96.8	461.8	462.3	533.4	49.2
500	20	698.5	635.0	31.7	20	42.9	558.8	73.0	144.5	103.2	513.1	514.3	584.2	54.0
600	24	812.8	749.3	34.9	20	47.6	663.6	82.5	152.4	111.1	615.9	615.9	692.1	63.5

ANSI B16.5 Blind Flanges Application

ASME B16.5 Blind Flanges are known to deliver exceptional performance and are generally developed for meeting the demands. We offer a broad range of Flat Faced Blind Flanges through a worldwide network of stock-keeping branches. These Blind Flange is use in various industries like :

Stainless Steel Blind Flanges, SS BLIND FLANGE uses in Oil and Gas Pipeline
Duplex Steel Blind Flange 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 Plate Flanges uses in Paper & Pulp Industry
ANSI B16.5 BLRTJ RING TYPE JOINT Blind Forged Flanges uses in Power Plant
Steel Blind Flanges uses in Fabrication Industry

FAQs

Who is the Leading Blind Flanges Manufacturer in India?

Shribhairav Forge, Proudly we can say we are the Leading Manufacturers and Exporters of All Types of Blind Flanges ranging from 150 Class to 2500 Class, AWWA C207, ANSI B16.47 Series A an Series B Blind Flanges and also Ring Type Joint BlindFlanges. Exporting Globally to US, UAE, European Union, Japan and even Australia.

What are the Grades in which do you Manufacturer Blind Flanges?

We at Shribhairav Forge manufacture a comprehensive range of Blind Flanges, BLRF FLANGE, BLRTJ RING TYPE JOINT BLIND FLANGES in various material grades conforming to ASME/ANSI B16.5 and PED-approved standards. Our production includes Stainless Steel Blind Flanges or SS Blind Flanges in grades ASTM A182 F304, F304L, F316, F316L, F310, F321, F347, and F904L; Duplex Steel Blind Flanges in grades ASTM A182 F51 / UNS S31803 and F60 / UNS S32205; and Super Duplex Steel Blind Flanges or Duplex Steel BLRF Flange in grades ASTM A182 F53 / UNS S32750 and F55 / UNS S32760. We also offer Carbon Steel Blind Flanges in grades ASTM A105, ASTM A350 LF2, and ASTM A694 F42 to F70, along with Alloy Steel Blind Flanges in grades ASTM A182 F1, F5, F9, F11, F12, F22, and F91. Our range further extends to Nickel Alloy Blind Flanges in grades Inconel 600, 625, Monel 400, Hastelloy C22, C276, and Incoloy 800, 825, as well as Copper Nickel Blind Flanges in grades Cu-Ni 70/30 (C71500) and Cu-Ni 90/10 (C70600). Additionally, we supply Titanium Blind Flanges in Grade 2 and Grade 5, and specialty materials such as SMO 254 (UNS S31254) and Nickel 200 / 201. All flanges are manufactured with precision to meet global quality standards and customer-specific requirements

How do you handle customer issues efficiently?

We handle customer issues efficiently by actively listening, identifying the root cause, and offering timely solutions. Clear communication and regular updates keep customers informed, while swift action and follow-up ensure a positive resolution.

What sets your service apart from competitors?

Our service stands out through personalized attention, quick response times, and a commitment to continuous improvement. We prioritize customer satisfaction, consistently adapting to feedback and industry trends to deliver exceptional, tailored experiences.