Editorial Technical Reference

Check Valve

This page explains how Check Valve is classified within Machinery and Equipment Manufacturing. Technical values and manufacturer relationships are research references; confirm the current specification and supplier evidence for each order.

Technical Definition & Core Assembly

A check valve is a one-way flow control device that allows fluid to pass in one direction while preventing backflow, protecting systems from reverse flow damage.

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Product Specifications

Technical details and manufacturing context for Check Valve

Definition
Check valves are widely used in piping systems for water, oil, gas, and chemical processing to prevent reverse flow that could cause contamination, water hammer, or equipment damage. They are specified by size, pressure rating, end connections, and cracking pressure. Grades differ by material quality, sealing performance, and durability under cyclic or high-temperature conditions. This directory entry covers industrial check valves as components, with typical parameters including nominal diameter (DN 15–600 mm per ISO 6708), pressure rating (PN 10–420 bar per ISO 7268), cracking pressure (0.05–0.5 bar), operating temperature (-29 to 425 °C), leakage rate (Class VI, 0.01% of rated flow per ISO 5208), flow coefficient (Cv 0.5–1200 US gal/min/psi), and end connections (flanged, threaded, welded per ASME B16.5). Body materials may include WCB (cast carbon steel), CF8 (304 stainless steel), CF8M (316 stainless steel), and brass (C36000); seat materials may include PTFE, PEEK, or nitrile. Design variants include swing, lift, ball, and diaphragm types. Surface finish ranges from Ra 0.8 to 3.2 µm per ISO 1302. Hydrostatic test pressure is 1.5 × PN and seat test pressure is 1.1 × PN per ISO 5208. Relevant standards include ISO 16136, API 6D, ASME B16.34, EN 1074-1, and GB/T 12236. These are procurement references; actual compliance must be verified with the manufacturer. Always confirm model-specific values and standards with the legal manufacturer or supplier before selection or installation.
Working Principle
The valve operates automatically based on differential pressure. When upstream pressure exceeds the cracking pressure, the disc or ball lifts off its seat, allowing flow. When downstream pressure exceeds upstream, the disc or ball is forced back onto the seat, creating a seal that blocks reverse flow. This passive mechanism requires no external actuation, making it suitable for fail-safe backflow prevention. The cracking pressure is the minimum upstream pressure required to open the valve; it varies by design and size. The sealing mechanism relies on the seat material and surface finish to achieve the specified leakage class. In cyclic or high-temperature service, material selection and maintenance are critical to maintain sealing integrity and prevent premature wear.
Common Materials
WCB (cast carbon steel), CF8 (304 stainless steel), CF8M (316 stainless steel), Brass (C36000), PTFE (seat material)
Technical Parameters
ParameterTypical rangeNotes & selection driver
Nominal Diameter15–300 mmStandard pipe sizesISO 6708
Operating Pressure1.0–1.6 MPaBelow 1.0 MPa the seat load is insufficientISO 5208
Operating Temperature-40–85 °CSeal material limits
Cracking Pressure0.05–0.1 MPaMinimum pressure to open
Leakage Rate≤0.1 mL/minAt 1.1× rated pressureISO 5208
Flow Coefficient (Cv)10–250 US gal/minAt full open
Body MaterialWCB/CF8/CF8MCarbon or stainless steelASTM A216/A351
Seal MaterialPTFE/NBR/EPDMChemical compatibility
End ConnectionFlanged/Threaded/WaferFlange rating matches pressureASME B16.5
Weight2–120 kgDepends on size and material

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Industry Taxonomies & Aliases

Commonly used trade names and technical identifiers for Check Valve.

Manufacturers of Check Valve

12 companies list this product among what they make. Company figures are quoted from each company's own website; every card states where the relationship came from.

ZFA Valve
Tianjin, Tianjin, CN
Founded 2006
ISO9001 CE WRAS ISO14001 +2
Also makes: Gate/Valve, Pneumatic Actuator, Valve Actuator and 2 more
Managed by the manufacturer
Listed on the company's own website
China Sanitary Valve
Zhejiang, CN
Founded 200251~100 staff5,000-10,000 square meters
ISO9001 ASME CE Test Report
Listed on the company's own website · profile compiled by CNFX from public sources
CHINA VIHUNG VALVE CO. LTD.
Shanghai, CN
Also makes: Butterfly Valve, Knife Gate Valve, Gate Valve and 2 more
Listed on the company's own website · profile compiled by CNFX from public sources
CJan Fluid Technology Co., Ltd.
Shanghai, CN
ISO 9001:2015 IATF 16949
Listed on the company's own website · profile compiled by CNFX from public sources
Dongying Lake Petroleum Technology CO., Ltd
Shandong, CN
ISO GOST
Listed on the company's own website · profile compiled by CNFX from public sources
Hydraflu Hydraulic Co.
Shanghai, CN
CE
Listed on the company's own website · profile compiled by CNFX from public sources
Jianen Sanitary
Wenzhou, Zhejiang, CN
Founded 2009
3A CE ISO9001 SGS
Listed on the company's own website · profile compiled by CNFX from public sources
Landee Industries
Xiamen, Fujian, CN
Founded 1994230+ staff
ASME U-Stamp
Also makes: Butterfly Valve, Heat Exchanger, Valve Actuator and 6 more
Listed on the company's own website · profile compiled by CNFX from public sources
Sunthai Extractor
Zhejiang, CN
200-500 staff20,000 m²
ISO 9001:2015
Listed on the company's own website · profile compiled by CNFX from public sources
Wenzhou Deyi Machinery
Wenzhou, Zhejiang, CN
Listed on the company's own website · profile compiled by CNFX from public sources
Donjoy Technology
Wenzhou, Zhejiang, CN
Listed on the company's own website · profile compiled by CNFX from public sources
HEBAI
Zhejiang, CN
Listed on the company's own website · profile compiled by CNFX from public sources
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Frequently Asked Questions

What is the function of a check valve?

A check valve allows fluid to flow in one direction only, automatically preventing reverse flow when downstream pressure exceeds upstream pressure. This protects piping systems and equipment from damage caused by backflow, such as water hammer or contamination.

How do I select the correct check valve size and pressure rating?

Selection is based on the required nominal diameter (DN) and pressure rating (PN) for your system, as well as the end connections and cracking pressure. Refer to the manufacturer's data for the specific model, and verify that the valve meets the applicable standards such as ISO 6708 and ISO 7268.

What materials are commonly used for check valve bodies and seats?

Common body materials include WCB (cast carbon steel), CF8 (304 stainless steel), CF8M (316 stainless steel), and brass (C36000). Seat materials may include PTFE, PEEK, or nitrile. Material choice depends on the fluid, temperature, and pressure requirements.

What maintenance is required for check valves?

Regular inspection for seat wear, disc movement, and leakage is recommended. Check for signs of erosion, corrosion, or debris buildup. Verify that the cracking pressure remains within specification. Follow the manufacturer's maintenance guidelines and replace worn parts as needed.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records.

Preliminary Technical Classification
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