In today’s demanding pipeline infrastructure, especially in petrochemical, metallurgy, and water treatment fields, the role of blind flange becomes ever more crucial for safety, reliability, and operational efficiency.
This extensive guide provides an in-depth analysis of blind flange and its subtypes, focusing specifically on the GOST 12836 PN 2.5/4.0 blind flange. We leverage up-to-date industry data, technical comparisons, and real-world case studies to support decision-makers, engineers, and procurement professionals worldwide.
Key Focus: Blind flange, blind pipe flange, stainless steel blind flange, threaded blind flange — technology, application, production, global standards, and competitive insights.
1. Blind Flange Industry Trends & Market Overview
A blind flange is a solid disk used to seal the end of a pipeline or to stop a flow within a piping system. The trending demand for process safety, compliance with international standards (ISO 9001, ANSI), and material performance is driving the exponential growth of blind flanges across key industries. According to Grand View Research (2023), the global flanges market (all types) is projected to surpass USD 7.8 billion by 2026, with blind flanges accounting for nearly 29% due to their vital role in system shut-off and pressure containment.
- High adoption: Oil & gas, petrochemical, power generation, food & beverage, water & wastewater sectors.
- Material evolution: From classic carbon steel to advanced stainless steel grades, enabling better corrosion resistance and service lifespan.
- Design advances: CNC precision machining, tighter dimensional tolerances, and customization according to GOST, ASME, ANSI, and EN standards.
2. Technical Parameters: Key Specifications of Blind Flanges
2.1 Common Blind Flange Types & Parameter Table
Type |
Standard |
Material |
Pressure Rating (MPa/PSI) |
Size Range (DN) |
Face Type |
Main Application |
Blind Flange |
ASME B16.5, EN 1092-1, GOST 12836 |
Carbon Steel, Stainless Steel |
PN2.5 to PN420 (300–6000 PSI) |
DN10–DN2000 |
RF/FF/RJ |
Pipeline Isolation, Testing |
Blind Pipe Flange |
ANSI/ASME/EN |
Duplex SS, Alloy Steel |
PN10–PN100 (150–1500 PSI) |
DN15–DN1500 |
RF/FF |
Repair, Maintenance, Isolation |
Stainless Steel Blind Flange |
ASTM A182 F304/F316 |
Stainless Steel (304/316L) |
PN6–PN100 |
DN20–DN600 |
RF/FF |
Corrosive, Chemical Services |
Threaded Blind Flange |
ASME B16.5 |
Steel, SS, Bronze |
PN16–PN64 (150–600 PSI) |
DN15–DN600 |
RF/FF |
Temporary Isolation, Non-Welded |
As shown, blind flange types and materials are determined by their end use, pressure rating, and international certification.
2.2 GOST 12836 PN 2.5/PN4.0 Blind Flange Technical Comparison
Parameter |
PN2.5 |
PN4.0 |
API605 (for reference) |
Standard |
GOST 12836-67 |
GOST 12836-67 |
API 605 |
Pressure Rating |
2.5 MPa (≈362 PSI) |
4.0 MPa (≈580 PSI) |
2.4 MPa (350 PSI) |
Material Options |
20# Steel, SS304, SS316 |
Q235B, 316L, 321 |
ASTM A105, A182, SS304 |
Face Type |
Raised Face (RF), Flat Face (FF) |
RF, FF |
RF, FF |
Size Range |
DN10–DN1200 |
DN10–DN1200 |
DN50–DN1200 |
Design Temp |
-30°C to +400°C |
-30°C to +550°C |
-29°C to +450°C |
Corrosion Resistance |
Good |
Excellent |
Good–Excellent (by grade) |
3. Blind Flange Manufacturing Process (with Visual Diagram)
Step-by-Step Process Overview
- Raw Material Selection: Certified steel billets (e.g., SS304, SS316) sourced per ISO or ANSI standards.
- Forging/Casting: Initial shape created by open die forging or precision sand casting.
- Heat Treatment: Achieving optimal microstructure, ensuring ductility and strength.
- CNC Machining: Finalizing dimensions, drilling holes & finishing faces with automated CNC lathes.
- Surface Finishing: Shot blasting, anti-rust painting, and branded marking per client needs.
- Inspection & Testing: Dimensional accuracy check, PMI (Positive Material Identification), hydrostatic/pressure test complying with ISO 5208.
- Packing & Shipping: Custom wooden/crate packing to protect during transport.
Note: Each process includes documented traceability for quality assurance.
- Materials Spotlight: Stainless steel grades (304, 316, 321, 316L) offer best-in-class corrosion resistance for harsh environments.
- Testing: 100% hydrostatic test and material traceability per ISO 5208/EN 1092-1 ensures leak-tight performance.
- Service Life: Superior manufacturing ensures 20+ years service life in most industrial scenarios.
4. Data Visualization: Technical Indicators & Performance Analysis
Blind Flange Material vs. Corrosion Resistance
Market Distribution of Blind Flange by Industry (2023)
GOST 12836 Blind Flange Failure Rate vs. Life (Cycle Test)
5. Technical Advantages and Standard Compliance
- Seamless shut-off capability for pressure testing and equipment maintenance.
- Superior corrosion resistance, especially with stainless steel blind flange and duplex options.
- Dimensional accuracy ensures leakproof connections per ISO 9624 and EN standards.
- User-specific threading possible – see threaded blind flange for non-welded connections.
- Versatile: Suitable for gases, liquids, and corrosive medias at different pressure classes.
- Long service cycles reduce maintenance shutdowns.
- Availability in compliance with GOST, ASME, ANSI, and other regional standards.
Certification & Industry Accreditations
Our
blind flange solutions are produced by
HBYS, an ISO 9001:2015 certified manufacturer. Flanges undergo third-party inspection and testing with certificates per
TÜV, SGS, and country-specific standards. Our company partners globally with PetroChina, Sinopec, and several international EPC contractors, delivering reliable service for over 20 years.
6. Manufacturer Comparison: Blind Flange Sourcing Decision Table
Brand/Manufacturer |
Origin |
Standard |
Product Range |
Custom Service |
Lead Time |
HBYS (China) |
China |
GOST 12836, ASME |
Blind, Socket, Weld Neck |
Yes (OEM/ODM) |
10-25 Days |
Bonney Forge |
USA |
ASME, EN |
Blind, Slip On, Weld Neck |
Partial |
30-45 Days |
Tenaris |
Italy/Global |
API, ISO |
All Types |
Limited |
35-50 Days |
Baoji |
China |
GOST, GB, ASME |
Blind, Weld Neck |
Yes |
12-28 Days |
For urgent projects or specialized requirements, HBYS GOST 12836 blind flange supports fast delivery and tailored design, outperforming most peers for Eastern European and Asian standards.
7. Customization Services & Application Scenarios
- Material upgrades (Duplex, Inconel, Monel) for severe chemical/petrochemical projects.
- Non-standard bore & face finish (serrated, spiral-wound), according to process needs.
- Special coatings (PTFE, epoxy) to extend flange durability in seawater or toxic service.
- OEM stamping/logo and barcoded traceability for project documentation.
- Threaded/hub designs for easy assembly/disassembly – choose threaded blind flange where welding is restricted.
- Fire-safe, low-temperature (cryogenic) modifications on request.
Case Study: Stainless Steel Blind Flange in Water Plant, Russia
In 2022, HBYS supplied 250 sets of GOST 12836 PN4.0 stainless steel blind flange (SS316L) for the St. Petersburg Municipal Water Works. The selection criteria included: chloride-rich environment, DN400 pipelines, and periodic high-pressure testing. Post-commissioning data (see chart above) shows blind flange maintained zero leakage and minimal surface corrosion over two years, outperforming conventional carbon steel flanges by up to 500% in corrosion test cycles.
Refinery Application – Threaded Blind Flange Retrofit
A Middle Eastern refinery required rapid isolation during turnaround. HBYS delivered threaded blind flange units, enabling workers to replace process equipment within 4 hours, cutting downtime by 35% versus welded flange options.
8. Product FAQ: Blind Flange Technical FAQ
Q1: What materials are available for blind flange production?
A: Standard options include carbon steel (A105, Q235B), stainless steel (SS304, SS316, SS321, 316L), duplex steel, and special alloys (Inconel, Monel) for enhanced resistance.
Q2: What are the main face types for a blind pipe flange?
A: Raised Face (RF), Flat Face (FF), and Ring Joint (RJ). RF is most common for sealing, while RJ is used for high-pressure pipelines.
Q3: Can I request non-standard sizes or OEM solutions?
A: Yes. Our GOST 12836 blind flange supports full customization in dimensions, drilling, surface finish, as per your project drawings or process codes.
Q4: Are stainless steel blind flange products suitable for seawater application?
A: Absolutely. SS316L and Duplex grades are specifically chosen for corrosion-prone and saline environments like offshore, desalination, and water treatment.
Q5: What pressure classes are available in blind flange?
A: PN2.5, PN4.0 (per GOST 12836), PN10 to PN420 (per various standards), and ANSI Class 150, 300, 600 up to Class 2500.
Q6: What is the difference between welded and threaded blind flange installation?
A: Threaded types permit non-welded, mechanical assembly, ideal for service where hot work is restricted or rapid access is needed.
Q7: What certifications accompany your blind flange shipments?
A: Each batch is supplied with ISO 9001, material test certificates (EN 10204 3.1/3.2), and third-party inspection reports upon client request.
9. Delivery, Warranty & Customer Support
Delivery Period: Typically 10–25 days from order confirmation, depending on quantity and custom features. All blind flange shipments are securely packed in durable wooden crates. International and DAP/FOB/CIF shipping options available.
Warranty: 18 months after shipment or 12 months after installation (whichever occurs first). Free technical support and on-site troubleshooting are provided globally.
Customer Support: Contact via email, phone, or online portal 24/7 for urgent technical queries, documentation requests, or claims handling. English, Russian, and Mandarin supported.
10. References & Authority Resources