GB Stainless Steel Swing Flange Check Valves

GB Stainless Steel Swing Flange Check Valves are automatic anti-backflow check valves designed in accordance with Chinese GB national standards.The main body is made of 304/316/316L stainless steel, and the valve opens and closes automatically by the pressure of the medium without external power.

During forward flow, the disc rotates around the hinge to open, ensuring smooth passage of the medium.In case of backflow, the disc closes rapidly under its own weight and reverse pressure to tightly block backflow, protecting pumps, compressors, heat exchangers and the entire pipeline system from impact and damage.

The stainless steel material provides excellent corrosion resistance, high temperature resistance and erosion resistance, while the flanged connection ensures easy installation, firm connection and strong sealing performance.

GB Stainless Steel Swing Flange Check Valves are widely used in GB-standard piping systems with high requirements for corrosion protection and sealing, such as petrochemical, municipal water supply and drainage, power, food and pharmaceutical industries.

Core Product Advantages

GB standard, high universality

Dimensions, flanges, pressure and structure are all designed to GB standards, enabling direct replacement of domestic valves of the same specification with zero installation adaptation issues.

All-stainless steel, corrosion-resistant and durable

Suitable for various corrosive environments such as chlorinated water, acid-base, sewage and chemical media, with service life much longer than ordinary carbon steel valves.

Swing structure with low flow resistance and stable operation

The disc opens by swinging, providing smooth flow passage, low pressure loss and sensitive opening/closing, effectively reducing water hammer impact.

Dual sealing options available

Metal hard seal for high temperature and particle-containing conditions; PTFE soft seal for clean, low-temperature and zero-leakage requirements.

Reliable flanged connection and easy maintenance

Easy assembly and disassembly, suitable for various industrial pipelines, pump stations, heat exchange stations and water treatment systems.

Core Technical Parameters

Design & Application Standards

The design, materials, processing and factory testing of this valve series strictly comply with the GB national standard system, featuring strong universality and good interchangeability.

● Swing check valve: GB/T 12236

● Pressure-temperature rating: GB/T 12224

● Face-to-face dimension: GB/T 12221

● Flange standard: GB/T 9113

● Material standards: GB/T 1220, GB/T 13401

● Seal overlay welding: GB/T 17491

● Pressure and seal test: GB/T 13927

● Installation specification: GB 50235

Component Materials

GB Stainless Steel Swing Flange Check Valves feature a full stainless steel body with strengthened sealing surfaces, providing consistent overall corrosion resistance and strength.

● Body / Bonnet: 304/316/316L stainless steel

● Disc: Stainless steel body + Stellite hard alloy overlay or PTFE soft seal ring

● Seat: Stainless steel base + hard alloy overlay layer

● Hinge mechanism: Forged stainless steel; shaft made of 17-4PH or 2Cr13

● Flange seal: 316L spiral wound gasket

● Bolts / Nuts: 304/316 stainless steel, consistent corrosion resistance with the body

Selection Guide

1. Selection by Pressure Class

● PN10/PN16: Municipal water supply & drainage, circulating water

● PN25/PN40: General industry, oil products, chemical engineering

● PN63/PN100: Medium-high pressure, high temperature, impact conditions

2. Selection by Disc Structure According to Diameter

● DN15～DN50: Single disc swing type, simple structure

● DN65 and above: Double / multiple disc type, reducing water hammer and vibration

3. Selection by Sealing Type According to Medium & Temperature

● Above 200℃, particles, high abrasion → Metal hard seal

● ≤200℃, clean medium, zero leakage required → PTFE soft seal

4. Selection by Material According to Corrosiveness

● Weak corrosion (water, air) → 304

● Medium corrosion (chlorine-containing, weak acid) → 316

● Strong corrosion, ultra-low temperature → 316L

5. Flange Face Matching

Confirm pipeline flange type: RF Raised Face / FM Male-Female Face / RJ Ring Joint Face to ensure consistency.

Installation & Maintenancev

Installation Requirements

● Verify pressure, diameter, material and flange face match the pipeline before installation

● Install in the flow direction indicated by the arrow

● Horizontal installation is preferred; reserve opening space on the disc side

● Tighten flange bolts diagonally and evenly

Routine Maintenance

● Regularly inspect flanges and bonnet seals for leakage

● Clean impurities in the valve cavity to avoid hinge jamming

● Apply high-temperature grease to the hinge shaft

● Worn sealing surfaces can be repaired by overlay welding to reduce operating costs

Troubleshooting

● Improper closing: Check for foreign matter or damage on disc, hinge and sealing surfaces

● External leakage: Retighten bolts or replace gaskets

● Stuck action: Disassemble, clean internal impurities and correct the hinge mechanism

Application Areas

With GB-standard universality, reliable corrosion resistance and stable sealing, GB Stainless Steel Swing Flange Check Valves are widely used in:

● Petrochemical industry and process pipelines

● Municipal water supply & drainage, chlorinated water treatment

● Power and power station auxiliary systems

● Food, pharmaceutical and clean fluid systems

● Metallurgy, shipbuilding, seawater and other corrosive medium pipelines