Forged Steel Valves

DN15 PN320 High Pressure Inline Union Check Valve

Non-return Valve (NRV)
Inline Check Valve
PN320 Check Valve
Union End / Three-piece Union
Description: High-Pressure PN320 Inline Union Check Valve | Forged Steel Non-Return Valve, PN320 check valve, high pressure inline check valve, union type non-return valve, forged steel piston check valve, 320 bar
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Product Overview

The PN320 High Pressure Inline Union Check Valve is a compact, robust flow-control solution designed for ultra-high-pressure pipeline systems. Featuring an inline piston or spring-loaded disc design, it ensures fast, automatic non-return action to prevent hazardous backflow.

The integrated union nut design allows for quick, effortless installation and maintenance without disturbing the piping system. Precision-machined to withstand extreme hydraulic and pneumatic forces, this valve provides bubble-tight sealing and ultimate structural integrity, making it ideal for high-pressure chemical injection, hydraulic systems, and oilfield applications.

Technical Specifications

Design & Manufacturing Standard: ASME B16.34 / EN 12516 / DIN 3852
Valve Type: Inline Lift / Spring-Loaded Check Valve
Nominal Pressure Rating: PN320 (32.0 MPa / 320 Bar / approx. Class 2500)
Body & Union Nut Material: ASTM A105, F316/F316L, F304/F304L, Duplex F51
Disc/Piston Material: SS316 / F316 Hardfaced with Stellite
Spring Material: Inconel X-750 (For high-temperature and fatigue resistance)
End Connection Type: Female NPT / BSPT Threaded, Socket Weld (SW), or Compression Fitting
Union Connection Standard: ISO 8434 / DIN 2353
Size Range: $1/4''$ to $2''$ (DN6 to DN50)
Seat Design: Integral Metal-to-Metal Seat (Stellite faced) or Peek Soft Seat
Cracking Pressure: Standard 0.5 Bar to 3 Bar (Custom spring rates available)
Flow Configuration: Straight-through Inline Flow
Sealing Style: Piston / Poppet type with guided movement
Hydrostatic Shell Test Pressure: 480 Bar (48.0 MPa by Water)
Hydrostatic Seat Test Pressure: 352 Bar (35.2 MPa by Water)
Pneumatic Seat Test Pressure: 6 Bar to 7 Bar (by Air)
Operating Temperature Range: -29°C to +250°C (Up to +425°C for pure metal-to-metal)
Flow Coefficient: High $C_v$ value with optimized internal flow path
NACE Compliance: MR0175 / ISO 15156 for sour gas environments
Testing & Inspection Standard: API 598 / EN 12266-1