API · ASME · DIN · EN standard industrial valves
Axial Flow Check Valves
Axial flow check valves close a spring-assisted, streamlined disc along the flow axis, so reverse flow is arrested before it can accelerate and slam — the no-water-hammer choice for high-velocity lines. The range spans NPS 2" to 60" (DN 50 to DN 1500) at ASME Class 150 to 2500 (PN 16 to PN 420), with carbon steel, stainless steel, alloy steel and duplex stainless steel bodies, RF, BW or RTJ end connections, a venturi-shaped flow path with metal-seated disc, long and short patterns, any-orientation installation, and API 6D / API 594 design. Selection turns on the pattern against installed length, the class against line pressure and transient, and the spring closure against the fluid medium.
Part of the Check Valves family
Last updated: 2026-11
Family specifications
| size range | NPS 2" to 60" (DN 50 to DN 1500) |
|---|---|
| pressure class | ASME Class 150 to 2500 (PN 16 to PN 420) |
| body materials | Carbon Steel, Stainless Steel, Alloy Steel, Duplex Stainless Steel |
| end connections | RF, BW, RTJ |
| operation | Self-acting (automatic) |
| temperature range | -196°C to 570°C |
| design standards | API 6D, API 594 |
| testing standards | API 598, API 6D, MSS |
| applications | High-flow systems, reciprocating pumps, pipeline transmission |
| ccv design feature | Compact design and short face to face to meet API 594 |
| ccv moving parts | One moving part resulting in minimal wear and long service life |
| ccv response feature | Quick dynamic response reducing reverse velocity and minimizing damaging water hammer |
| ccv stroke feature | Short stroke to help in quick response |
| ccv spring options | Choice of springs for specific critical velocity and valve response |
| ccv reciprocating service | Suitable for reciprocating compressor service eliminating chatter |
| ccv spring design | Spring is internal and protected from process flow |
| ccv preferred service | Preferred in centrifugal compressor service |
| ccv size range | 12′′ – 60′′ |
| ccv pressure rating | Class 150 – 4500 |
| ccv api 6a rating | Class 2000 – 15,000 |
| ccv body configuration | Flanged, butt-weld ends, hub ends and specials |
| ccv face to face standard | Face to face design to API 594 |
| ccv axial performance | axial check valve performance and reliability |
| fls model | Model NZ & NZS Axial Flow Nozzle Check Valve |
| fls size range | 1/2′′ – 72′′ |
| fls pressure class | ASME Class 150 – 2500 |
| fls design feature | High performance, non-slam, reliable design for applications where low pressure loss and zero downtime are driving factors |
| fls wafer variant | Model NZW API 594 Axial Flow Wafer Check Valve |
| lnd design standard | API 6D |
| lnd size range | NPS 2-60 Inch |
| lnd pressure range | Class 150-2500 LB |
| lnd body materials | Carbon Steel, Stainless Steel, Duplex Stainless Steel, Alloy Steel, Nickel Alloy |
| lnd end connections | RF/RTJ/BW |
| standards | API 6D, API 594 |
| flow design | Streamlined venturi-shaped design for optimized flow |
| closure mechanism | Spring-assisted closure for rapid response |
| seat design | Metal-seated disc for durable sealing |
| installation orientation | Suitable for installation in any orientation |
| pattern options | Long pattern, Short pattern |
Ordering & documentation
Documents
Ask for the documentation set with the inquiry — typical items (material certificates, test reports to the listed inspection standard, dimensional drawings) are confirmed and supplied with the quotation.
Quotation
Send the medium, temperature, pressure, size and connection for a quotation-ready inquiry. Lead time, MOQ and price are confirmed at quotation, together with the documents to be supplied with the order.
Sample & supply
Supply terms, order quantities and lead time are agreed per order — state the destination country and required schedule with the inquiry.
Storage & shipping
Store valves with seats and seals protected from UV, ozone and deformation, and keep end-face protectors on until installation; storage limits and shipping arrangements for the selected materials are confirmed at quotation.
Frequently asked questions
What standards govern the design and testing of axial flow check valves?
The published specification for this family lists API 6D, API 594 as the design standards. Testing follows API 598, API 6D, MSS.
What sizes and pressure ratings are available for axial flow check valves?
The published size range is NPS 2" to 60" (DN 50 to DN 1500), and the published pressure ratings are ASME Class 150 to 2500 (PN 16 to PN 420). Availability of a specific size and rating is confirmed at quotation.
What materials are axial flow check valves available in?
The published specification lists body materials: Carbon Steel, Stainless Steel, Alloy Steel, Duplex Stainless Steel. Material availability for a specific size and rating is confirmed at quotation.
What working temperature range do axial flow check valves cover?
The published working temperature range is -196°C to 570°C. For a medium at the edge of the range, confirm the suitability of the selected seat and body materials at quotation.
What end connections do axial flow check valves support?
The published specification lists RF, BW, RTJ as the available end connections. The connection for a specific size is confirmed at quotation.
What should a quotation inquiry for axial flow check valves include?
The governing standard and class, nominal size, body and seat materials, the service medium with temperature, and the destination — anything missing is confirmed during quotation.
Request a quote for axial flow check valves
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Get a quotation for Axial Flow Check Valves
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