API 594 ASME B16.5 CE DN80 Class 150LB ASTM A216 WCB Flanged Swing Check Valve

I. Important Attribute and Specification Description

A. Global Standard Compliance & Product Core Definition

The TIANYU Swing Check Valve is a bolted bonnet swing-type non-return valve fully engineered in accordance with internationally recognized industrial valve standards including API 594, ASME B16.34, ASME B16.5, ASME B16.10, and EU CE safety certification, delivering reliable one-way flow isolation and medium backflow prevention for general industrial, petrochemical, power and municipal piping systems. This valve adopts classic swing disc internal structure, with the disc hinged on an internal pivot shaft to freely swing open under forward medium flow pressure and tightly attach to valve seat to cut off reverse fluid flow once pipeline pressure reverses. The product is equipped with standard raised face flanged end connections and bolted top cover sealed by flexible graphite composite gasket, without auxiliary spring components, which greatly reduces fluid flow resistance during normal pipeline operation. All dimensional indexes follow unified ASME dimensional specifications to realize full interchangeability with global standard pipeline flanges, which simplifies on-site installation, regular maintenance and spare parts replacement for EPC contractors and plant operation departments. All finished products pass API 598 standardized hydrostatic and air tightness testing before delivery, satisfying market access audit requirements for North America, European Union, Middle East and Southeast Asia industrial engineering projects.

B. Quantified Complete Technical Performance Parameters

Parameter Category	Standardized Performance Index
Nominal Pipe Size	3 Inch (DN80)
Pressure Class Rating	Class 150LB as per ASME B16.34 pressure grade standard
Main Valve Body Material	ASTM A216 WCB Cast Carbon Steel
Cover Gasket & Sealing Packing	Flexible Graphite Spiral Wound Composite Gasket
End Connection Type	RF Raised Face Flanged Connection matching ASME B16.5 bolt layout
Internal Swing Disc Material	ASTM A105 Carbon Steel with 13Cr Hardfaced Sealing Surface
Pivot Shaft Material	ASTM A182 F6a Martensitic Stainless Steel
Applicable Working Temperature Range	-29°C ~ +425°C adapting steam, hot oil and normal temperature liquid medium
Shell Hydrostatic Test Pressure	1.5 times of Class 150LB rated working pressure regulated by API 598
Seat Tightness Test Pressure	1.1 times of nominal working pressure with ANSI B16.104 Class VI zero bubble leakage
Standard Face-to-Face Length	Fixed dimension following ASME B16.10 swing check valve dimensional standard
Flow Resistance Coefficient	Low drag coefficient without spring blocking inside flow channel

The ASTM A216 WCB cast carbon steel valve body is processed through standardized normalizing heat treatment, with minimum tensile strength reaching 485MPa and minimum yield strength hitting 240MPa, possessing excellent impact resistance and structural stability under alternating temperature and pressure working conditions, widely compatible with steam, industrial water, crude oil, natural gas and most neutral non-corrosive industrial fluids. The internal swing disc is hardfaced with 13Cr alloy on the sealing contact surface after precision machining and lapping, forming rigid metal-to-metal sealing pair with valve body seat, which maintains stable tight shut-off performance under high temperature medium erosion without aging deformation like soft rubber sealing materials. The pivot shaft adopts quenched and tempered F6a stainless steel raw material, effectively resisting medium corrosion and galling abrasion during long-term reciprocating swing movement, avoiding disc jamming failure caused by shaft rusting. The bolted top cover is matched with flexible graphite spiral wound gasket as static sealing component, the layered graphite composite structure retains stable sealing performance under high temperature fluctuation, effectively blocking medium leakage at the body-cover joint. The flanged raised face connection surface is machined with serrated anti-slip texture, which increases gasket attaching friction and prevents medium seepage under pipeline pressure fluctuation. The valve body internal flow channel adopts streamlined casting design to reduce medium turbulence and pressure loss during forward circulation, which optimizes overall pipeline transmission efficiency compared with lift-type check valve products with narrow flow passage.

API 594 ASME B16.5 CE DN80 Class 150LB ASTM A216 WCB Flanged Swing Check Valve

II. Manufacturing Technology and Core Product Features

A. Full Process Standardized Manufacturing & Multi-Stage Quality Control Mechanism

All production procedures of TIANYU WCB swing check valve are completed in an ISO9001:2015 certified standardized production workshop, every processing link is equipped with strict incoming material inspection, semi-finished product intermediate detection and finished product full-item performance test procedures to ensure all finished product indexes fully comply with international design specifications.

Raw Material Inbound Inspection: All WCB casting ingots, F6a shaft bar, 13Cr surfacing welding wire and flexible graphite gasket raw materials are sent to factory physical and chemical laboratory for spectral composition analysis and mechanical property sampling test. Only raw material batches that meet chemical component ratio, tensile strength and hardness standards can enter the subsequent processing flow; unqualified raw material batches are directly returned to suppliers to eliminate defective sources at the front end of production.
Precision Casting and Stress Relief Heat Treatment: Valve body and cover blanks adopt sand casting technology optimized for streamline internal flow channel, which effectively reduces casting defects such as sand holes, shrinkage cavities and cold shut. After casting forming, blanks are placed in high-temperature furnace for normalizing heat treatment to homogenize internal metal grain structure and eliminate casting residual stress, improving the overall structural impact resistance of the valve body. After heat treatment, all cast blanks implement 100% MT magnetic particle inspection and UT ultrasonic non-destructive flaw detection according to ASME V specification to eliminate invisible internal and surface crack defects that threaten long-term service safety.
CNC Precision Machining of Key Sealing Components: Valve body seat surface, swing disc sealing surface, pivot shaft matching hole and flange positioning surface are processed by horizontal CNC machining center with micron-level dimensional tolerance control. The sealing contact surface of seat and disc undergoes fine grinding and manual lapping process to reach Ra0.8μm surface roughness, ensuring complete close fitting between sealing pairs after assembly to achieve zero leakage shut-off effect. The pivot shaft outer circle adopts centerless grinding to obtain smooth mirror surface, reducing friction loss during disc swing operation.
Cover Sealing Gasket Matching and Pre-Compression Treatment: Flexible graphite spiral wound gaskets are cut and formed according to standard dimensional parameters, each gasket undergoes fixed tonnage hydraulic pre-compression to eliminate elastic shrinkage deformation during later high-temperature operation. Random sampling of gaskets from each batch carries out high-temperature aging simulation test to verify long-term sealing stability under cyclic temperature change environment.
Clean Assembly and Complete Finished Product Performance Test: All internal assembly work is completed in a dust-free assembly area, all cover fastening bolts are locked by calibrated digital torque wrench according to unified torque value to avoid uneven gasket compression causing static sealing failure. After assembly, all finished valves sequentially complete shell hydrostatic pressure test, seat air tightness leakage test, full swing cycle endurance test and high-temperature thermal stability test formulated by API 598. Products failing any test item enter designated rework process instead of being delivered to finished product warehouse; only fully qualified valves receive anti-rust epoxy coating and standard export wooden box packaging before shipment to global customers.

B. Distinctive Core Structural Product Features

Streamlined Swing Disc Non-Blocking Flow Channel Design: The internal swing disc structure without built-in spring components maximizes the effective circulation area of the pipeline, greatly reducing medium flow resistance and pipeline pressure loss during forward fluid transportation, which optimizes the overall energy consumption of fluid transmission equipment such as pumps and compressors.
High Temperature Resistant Flexible Graphite Static Sealing System: The flexible graphite spiral wound gasket between valve body and bolted cover breaks through the temperature limit of ordinary rubber gaskets, maintaining stable sealing performance under continuous working temperature up to 425°C without melting, aging or permanent deformation, effectively preventing medium leakage at the bonnet joint.
Hardfaced 13Cr Metal-to-Metal Sealing Pair: The swing disc and valve body seat are both processed with 13Cr alloy hard surfacing, forming rigid metal sealing matching surface, which delivers ANSI Class VI bubble-tight zero leakage performance under full Class 150LB rated differential pressure, suitable for high-temperature steam and high-viscosity crude oil medium service that cannot use soft sealing materials.
Robust WCB Cast Carbon Steel Main Body: ASTM A216 WCB cast carbon steel raw material has excellent mechanical strength and impact resistance, adapting to complex working conditions of alternating pressure and temperature fluctuation in industrial pipelines, compatible with dozens of common industrial fluid media without material corrosion failure.
Corrosion Resistant F6a Stainless Steel Pivot Shaft: Heat treated F6a martensitic stainless steel pivot shaft balances surface hardness and core material toughness, resisting medium erosion and friction galling during long-term swing cycle operation, effectively avoiding disc stuck failure caused by shaft rust and wear.
Standard ASME Flanged RF End Connection: Raised face flanged structure fully complies with ASME B16.5 dimensional standards, matching all mainstream international standard pipeline flanges, with serrated flange surface enhancing gasket anti-slip performance and long-term pipeline sealing stability.
Global Full-Set Authorized Certification Support: The whole product R&D, production and testing system is audited and certified by ISO9001 quality management system, EU CE safety certification and API 598 performance verification, all technical parameters meet North American and European industrial procurement standards, which helps the product enter global EPC engineering tender procurement list smoothly.

III. Comprehensive Multi-Dimensional Product Competitive Advantages

Ultra-Low Flow Resistance Reduces Long-Term Pipeline Operation Cost: Without spring obstruction inside the flow channel, the swing check valve’s streamlined internal structure cuts fluid pressure loss by more than 40% compared with lift-type check valves, lowering the power consumption of supporting pumps and compressors for end-user factories and continuously reducing daily production operation expenditure.
Extraordinary Long Service Life Cuts Spare Parts Replacement Expense: The friction-free swing disc opening-closing structure and wear-resistant 13Cr hardfaced sealing pair greatly reduce sealing surface abrasion loss, the average stable service cycle under standard working conditions exceeds 10 years, effectively cutting the cost of purchasing spare valves and pipeline shutdown maintenance loss caused by frequent replacement.
Wide Medium and Temperature Adaptability Scope: Matching combination of WCB carbon steel body, F6a anti-rust pivot shaft, metal hard seal and flexible graphite high-temperature gasket enables stable operation in media including steam, natural gas, crude oil, industrial circulating water and mild neutral solvents within temperature range from -29°C to 425°C, realizing one single valve model to satisfy multiple production condition matching demands of industrial enterprises.
Excellent Total Ownership Cost Control for End Users: WCB carbon steel raw material has lower procurement cost compared with duplex and austenitic stainless steel valves; the zero leakage metal sealing structure eliminates economic loss caused by valuable medium backflow leakage, and the low maintenance design reduces routine overhaul labor and material expenditure, lowering the full lifecycle comprehensive operation cost of the valve for factory users.
Superior High-Temperature Working Condition Adaptability: Flexible graphite gasket and all-metal sealing system avoid the aging, melting and failure defects of polymer soft sealing materials under high temperature steam service, perfectly matching boiler steam pipeline, thermal power condensate recovery pipeline and refinery high-temperature oil delivery pipeline working environments.
Simple Maintenance Structure Saves On-Site Overhaul Time: Bolted top cover design allows operators to disassemble the cover and take out internal swing disc and pivot shaft components without removing the whole valve from the pipeline, greatly shortening the pipeline shutdown overhaul time and reducing production interruption loss caused by valve maintenance.
Stable Anti-Water Hammer Performance for Pipeline Safety Protection: The swing disc opens and closes slowly under medium pressure buffering, which effectively weakens pipeline water hammer impact generated by sudden medium backflow, protecting downstream pipeline equipment such as pumps, heat exchangers and pressure vessels from impact damage and improving overall pipeline operation safety.

IV. Global Multi-Industry Industrial Application Scopes

The TIANYU 3 Inch Class 150LB WCB Flanged Swing Check Valve with flexible graphite gasket and metal hard seal is specially developed for industrial pipeline systems requiring reliable one-way anti-backflow protection, its low flow resistance, high temperature resistance and stable tight shut-off performance make it widely selected by global factory end users and international EPC engineering contractors across multiple core industrial sectors.

Thermal Power & Cogeneration Power Plant Industry: Widely installed on boiler saturated steam delivery pipeline, condensate recovery circulating pipeline and cooling water circulation pipeline of thermal power stations, the high temperature resistant flexible graphite gasket and metal hard seal maintain stable anti-backflow performance under long-term high temperature steam scouring, and the low flow resistance structure optimizes the circulation efficiency of boiler auxiliary pipeline system, effectively preventing high temperature steam backflow from damaging boiler feedwater pumps.
Petrochemical & Crude Oil Refining Plant: Deployed on crude oil transmission main pipeline, natural gas gathering pipeline and finished oil product delivery piping inside refineries, the metal-to-metal hard seal avoids swelling and aging failure of soft sealing materials under high temperature hydrocarbon medium erosion, the slow swing disc structure weakens pipeline water hammer impact during pump shutdown, protecting precision refinery process equipment from backflow medium impact damage.
Municipal Water Supply & Central Heating Pipeline Network: Applied on urban municipal tap water delivery trunk pipeline and cogeneration central heating high-temperature hot water pipeline, the WCB carbon steel body adapts to normal and medium temperature water medium working conditions, standard flanged connection matches municipal engineering pipeline construction standards, stable anti-backflow function prevents pipeline medium reverse flow caused by water supply pressure fluctuation to avoid regional heating and water supply system operation failure.
General Chemical Processing Factory: Used on neutral solvent circulation pipeline, industrial cooling water loop and low-temperature process gas transmission piping of chemical manufacturing workshops, the wide temperature adaptation range and anti-corrosion WCB body meet the anti-backflow protection demand of conventional chemical fluid pipelines, the simple disassembly structure facilitates regular internal dirt cleaning for medium containing tiny solid particles.
Oil & Gas Midstream Transmission Station: Installed on natural gas compressor outlet pipeline and crude oil pipeline transfer station piping, the low flow resistance design reduces gas and oil transmission pressure loss, the all-metal sealing system eliminates the risk of flammable gas leakage caused by soft seal aging, improving the safety level of oil and gas transmission station operation.
Food Processing & Light Industrial Production Line: Adopted on high-temperature cleaning steam pipeline and neutral process water circulation pipeline of food and light industrial workshops, the metal hard seal avoids organic rubber seal fragment shedding pollution to clean production medium, satisfying basic hygiene production requirements of food processing industry.