Plastic Check Valves

Industrial Plastic Check Valves

Plastic check valves prevent backflow and reverse rotation in fluid handling systems where metal valves fail due to chemical corrosion, oxidation, or weight constraints. Operating automatically via line pressure differential, these non-return valves isolate downstream media, protect pumps against water hammer, and maintain system priming across municipal, chemical, and industrial fluid networks.

Using corrosion-resistant thermoplastics including UPVC, CPVC, PVDF, and PPH, these check valves handle aggressive acids, alkalis, high-purity water, and abrasive slurries without leaching metal ions or scaling internal flow channels.

Product Range

PVC Swing Check Valve

Designed for low-pressure-drop applications in unplasticized polyvinyl chloride piping systems. Utilizes a free-swinging or spring-assisted disc design to maximize flow capacity with minimal cracking pressure.
Size Range: DN15 - DN300 (1/2" - 12")
Temperature Range: 0°C to 60°C (32°F to 140°F)
Body Material: Unplasticized PVC (UPVC)
Sealing Material: EPDM / FKM

CPVC Swing Check Valve

Extends the chemical resistance of standard PVC to elevated temperature processing. Suitable for hot corrosive liquids, industrial waste handling, and acid distribution lines.
Size Range: DN15 - DN300 (1/2" - 12")
Temperature Range: 0°C to 90°C (32°F to 194°F)
Body Material: Chlorinated PVC (CPVC)
Sealing Material: FKM / EPDM

PVDF Check Valve

Engineered for ultra-pure water, high-concentration acids, and high-temperature chemical process lines. Provides chemical resistance across a broad pH spectrum alongside high mechanical strength.
Size Range: DN15 - DN100 (1/2" - 4")
Temperature Range: -40°C to 120°C (-40°F to 248°F)
Body Material: Polyvinylidene Fluoride (PVDF)
Sealing Material: FKM / FFKM / PTFE Coated

PPH Check Valve

Optimized for industrial chemical distribution, electroplating, and pickling lines. Features stress-crack resistance and impact strength at elevated operating temperatures.
Size Range: DN15 - DN200 (1/2" - 8")
Temperature Range: 0°C to 95°C (32°F to 203°F)
Body Material: Polypropylene Homopolymer (PPH)
Sealing Material: EPDM / FKM

Plastic Wafer Check Valve

Short face-to-face dimension design clamped between ANSI or DIN flanges. Ideal for space-constrained piping layouts requiring full-flow backflow prevention.
Size Range: DN40 - DN400 (1-1/2" - 16")
Temperature Range: 0°C to 90°C (Material dependent)
Body Material: UPVC / CPVC / PPH / PVDF
Mounting Pattern: Fits ANSI CL150, DIN PN10/PN16, JIS 10K

Plastic Foot Valve

Installed at the bottom of pump suction lines to hold liquid column priming and filter out suspended solids via an integrated intake strainer.
Size Range: DN15 - DN100 (1/2" - 4")
Temperature Range: 0°C to 60°C (UPVC) / 0°C to 90°C (CPVC)
Body Material: UPVC / CPVC
Strainer Screen: Perforated Thermoplastic Mesh

Key Product Characteristics

Zero Metallic Contact

Eliminates metal ion contamination in high-purity water treatment and electronic chemical delivery systems.

Low Cracking Pressure

Internal disc and spring geometries open fully at pressures below 0.05 bar (0.72 psi), reducing head loss and pump energy consumption.

Hydrodynamic Sealing

Elastomeric seats (EPDM or FKM) provide bubble-tight sealing under minimal backpressure conditions.

Smooth Internal Bore

Injection-molded internal surfaces prevent scale buildup, minimize pressure drop, and reduce turbulence.

Modular Repairability

True union and wafer designs enable inline seat and seal replacement without cutting pipeline sections.

Material & Media Compatibility

Material	Max Operating Temp (°C / °F)	Max Pressure Rating (at 20°C)	Chemical Compatibility	Unsuitable Media
UPVC	60°C / 140°F	PN10 - PN16 (150-230 PSI)	Dilute acids, alkalis, salts, aliphatic hydrocarbons	Aromatic hydrocarbons, esters, ketones, chlorinated solvents
CPVC	90°C / 194°F	PN10 - PN16 (150-230 PSI)	Hot corrosive liquids, mineral acids, sodium hypochlorite	Concentrated nitric acid, ketones, ethers
PPH	95°C / 203°F	PN10 (150 PSI)	Caustics, pickling acids, electroplating solutions	Oxidizing acids (concentrated HNO3, H2SO4), halogens
PVDF	120°C / 248°F	PN10 - PN16 (150-230 PSI)	Concentrated acids, chlorine, bromine, ozone, high-purity media	Fuming sulfuric acid, strong caustic solutions (pH > 12 at high temp)

Connection & Configuration Options

Socket / Solvent Weld

ASTM D2467 / DIN 8063 standard socket ends for rigid PVC and CPVC pipeline jointing.

Threaded (NPT / BSPT)

Tapered internal/external threads compliant with ANSI B1.20.1 and ISO 7-1.

Infrared (IR) / Butt Fusion

Spigot ends for socket-fusion or bead-free IR welding on PPH and PVDF piping runs.

Flanged & Wafer

Standardized pattern matching ANSI B16.5 Class 150, DIN PN10/PN16, and JIS 10K drillings.

Key Specifications

Nominal Diameters	DN15 to DN400 (1/2" to 16")
Working Pressure (PN)	PN6, PN10, PN16 at 20°C ambient fluid temperature
Cracking Pressure	Standard spring: 0.03 - 0.05 bar (0.43 - 0.72 psi); Gravity swing:< 0.01 bar (0.14 psi)
Seat Sealing Standards	ISO 5208 Rate A (Zero visible leakage)
Design Standards	ISO 16137, DIN 3441 / 3442, ASTM F1970
Face-to-Face Dimensions	DIN 3202, EN 558-1, ANSI B16.10

How to Select the Right Plastic Check Valve

Step 1: Identify Chemical Composition & Concentration

Cross-reference your process fluid with polymer corrosion tables. Ensure both body polymer and elastomeric seals (EPDM vs. FKM) withstand chemical exposure at maximum operating concentrations.

Step 2: Calculate Temperature-Derated Operating Pressure

Polymer tensile strength decreases as fluid temperature rises. Apply pressure derating factors:
At 40°C, reduce rated working pressure of UPVC by 30%.
At 80°C, CPVC operates at maximum 40% of its nominal 20°C pressure rating.

Spring Check Valve CPVC Swimming Pool Valve

Step 3: Determine Orientation and Flow Velocity

Vertical Flow (Upward): Requires spring-assisted ball or swing design to ensure positive seating when flow stops.
Horizontal Flow: Standard gravity swing check or spring check valves function within nominal velocity parameters (0.5 m/s <= V <= 2.5 m/s).

Step 4: Evaluate Allowable Head Loss

For low-head pumping systems, choose Swing Check or Wafer Check valves, which offer full-bore openings and lower pressure drop (K-value) than inline spring-loaded ball check valves.

Applications

Industrial Wastewater & Effluent Treatment

Prevents chemical slurry backflow in acid/alkali neutralization tanks, filter press feed lines, and dosing pump discharge systems.

Chemical Processing & Distribution

Handles concentrated acid transport (HCl, H2SO4), sodium hypochlorite injection, and industrial electroplating tank recirculation.

Semiconductor & Pure Water Handling

PVDF and clean-washed UPVC check valves maintain flow integrity in Reverse Osmosis (RO), Deionized (DI) water lines, and clean-in-place (CIP) rinse units without ionic leaching.

Marine & Desalination Plant Systems

Resists saltwater corrosion, bio-fouling, and sodium chloride scaling in intake raw water processing and brine discharge lines.

Quality & Inspection

To verify pressure integrity, seat tightness, and dimensional tolerance, production batches undergo rigorous testing protocols:

Shell Hydrostatic Test

Conducted at 1.5 x nominal pressure (e.g., 24 bar for PN16 rating) using water to verify structural body integrity.

Low-Pressure & High-Pressure Seat Leak Test

Tested at 0.2 bar and 1.1 x PN according to ISO 5208 Rate A standards to ensure zero seat leakage.

Raw Material Spectrometry & Melt Flow Indexing

Verification of resin purity via FTIR spectroscopy and Melt Flow Index (MFI) batch sampling prior to injection molding.

Dimensional Verification

Critical tolerances on thread profiles, socket depth (ASTM/DIN), and sealing ring grooves are verified using CMM and optical profile projectors.

OEM / ODM & Customization

We provide customized valve manufacturing to suit proprietary piping systems and specialized industrial applications:

Custom Mold Design & Tooling: In-house CNC toolmaking for custom body dimensions, unique end connection standards, or non-standard face-to-face lengths.

Tailored Cracking Pressures: Custom spring rate selection (304 SS, 316 SS, Hastelloy C-276, or PTFE-coated springs) to achieve specific opening differential pressures from 0.01 bar to 0.5 bar.

Alternative Elastomers: Integration of specialty sealing materials including FFKM, NBR, or silicone for niche chemical or food-contact requirements.

Private Labeling & Packaging: Custom laser marking of part numbers, logos, pressure ratings, and trace codes directly on valve bodies, accompanied by customized retail or industrial packaging.

FAQ

Q: What is the main difference between a Swing Check Valve and a Ball Check Valve?

A: A Swing Check Valve utilizes a hinged disc that swings open under forward flow, offering lower pressure drop (K-value) and higher flow capacity. A Ball Check Valve uses a guided sphere that lifts off its seat; it handles dirty fluids and slurries better because the liquid rotation cleans the ball surface during operation.

Q: How do temperature increases affect the pressure rating of plastic valves?

A: As fluid temperature increases, thermoplastic materials undergo thermal expansion and tensile yield strength reduction. Every plastic valve must be pressure-derated according to the specific material curve (e.g., a UPVC valve rated at 16 bar at 20°C drops to approximately 4 bar at 60°C).

Q: Can plastic check valves be installed vertically?

A: Yes, provided the flow direction is upward. Upward vertical flow pushes the disc or ball open, and gravity (or spring assist) helps seal the valve against backpressure during pump shutoff. Downward vertical installation is generally not recommended unless a strong internal spring is installed to ensure positive valve closure.

Q: Which material should I choose for sodium hypochlorite (NaClO) media?

A: CPVC or PVDF bodies fitted with FKM (Viton) seals are recommended for sodium hypochlorite dosing lines. Standard UPVC can be used for low concentrations at ambient temperatures, but standard EPDM seals will degrade over prolonged exposure to aggressive sodium hypochlorite.

Q: How do spring-assisted check valves compare to gravity-closed check valves?

A: Spring-assisted check valves close faster before fluid reversal occurs, mitigating water hammer in high-head pumping systems. Gravity-closed valves rely purely on backflow pressure and media density, making them suitable for low-pressure systems where minimal cracking pressure is required.

Q: What connection standards are available for international piping integration?

A: Valves are produced to conform to major regional standards:
Socket: Metric (DIN 8063 / ISO), ASTM (Sch 40/80), JIS.
Threaded: NPT (ANSI B1.20.1) and BSPT/BSPP (ISO 7-1).
Flanged: ANSI Class 150, DIN PN10/PN16, and JIS 10K patterns.

Request a Quote

Require technical sizing support, material compatibility verification, or a price quote for high-volume orders?
Submit your project requirements to receive a complete technical data sheet and quotation within 24 hours.
Required Specification Details for Quick Quotes:
Valve Type & Nominal Size (DN / Inch)
Body Material (UPVC, CPVC, PPH, PVDF) & Seal Material (EPDM, FKM)
End Connection Standard (ANSI / DIN / JIS; Socket / Threaded / Flanged / Wafer)
Media Type, Operating Temperature (°C), and Maximum Working Pressure (bar/PSI)
Estimated Order Quantity & Target Delivery Timeline

We're well-known as one of the leading plastic check valves manufacturers in China. If you're going to buy high quality plastic check valves in stock, welcome to get quotation and free sample from our factory. Also, customized service is available.