Plastic Wafer Check Valve
The plastic wafer check valve prevents backflow in corrosive and high-purity fluid handling systems. Its ultra-compact, flangeless body installs directly between standard ANSI Class 150, DIN PN10/16, or JIS flanges without dedicated mounting hardware or extensive piping modifications.
Description
Product Overview
The plastic wafer check valve prevents backflow in corrosive and high-purity fluid handling systems. Its ultra-compact, flangeless body installs directly between standard ANSI Class 150, DIN PN10/16, or JIS flanges without dedicated mounting hardware or extensive piping modifications.
Operating on a low-cracking-pressure swinging or disc-check mechanism, this valve maintains unidirectionality with minimal head loss. Thermoplastic construction eliminates external shell corrosion and fluid contamination, making it a drop-in alternative to heavy alloy check valves in aggressive chemical media, water treatment, and industrial liquid processing lines.
Key Product Characteristics
Flangeless Wafer Design: Fits tight face-to-face dimensions to optimize skid footprint and lower structural pipe support requirements.
Non-Metallic Wetted Path: Pure thermoplastic body and disc options eliminate galvanic corrosion and metal ion leaching into process fluids.
Low Cracking Pressure: Fully opens at fluid pressures under 0.05 bar (0.73 psi) to reduce system pump load and head loss.
Multi-Flange Compatibility: Single body pattern aligns automatically with ANSI, DIN, and JIS bolt circles.
Vertical or Horizontal Mount: Operates in both horizontal pipelines and vertical runs with upward flow directions.
Key Specifications
|
Parameter |
Specification / Range |
|
Nominal Sizes |
DN40 – DN300 (1-1/2" – 12") |
|
Pressure Rating |
PN10 / PN16 (up to 16 bar / 232 psi at 20°C) |
|
Operating Temperature |
PVC-U: 0°C to 60°C | CPVC: 0°C to 95°C | PPL/PP-H: -10°C to 90°C | PVDF: -40°C to 120°C |
|
Cracking Pressure |
0.02 bar – 0.05 bar (0.29 – 0.73 psi) |
|
Face-to-Face Standard |
ISO 5752 / EN 558 Series 23 |
|
Flange Standard Alignment |
ANSI B16.5 Class 150, EN 1092-1 PN10/PN16, JIS B2220 10K |
|
Seat & Seal Materials |
EPDM, FKM (Viton), PTFE (encapsulated) |
Materials & Media Compatibility
Body & Disc Options
PVC-U (Unplasticized Polyvinyl Chloride): Cost-effective selection for general water treatment, municipal wastewater, diluted acids, and alkaline solutions up to 60°C.
CPVC (Chlorinated Polyvinyl Chloride): Enhanced thermal stability up to 95°C. Resistant to hot corrosive acids, bleach, and sodium hypochlorite solutions.
PP-H / PPL (Polypropylene Homopolymer): Excellent resistance to industrial solvents, organic chemicals, and pickling solutions up to 90°C.
PVDF (Polyvinylidene Fluoride): Premium purity polymer for ultrapure water (UPW), concentrated acids (nitric, sulfuric, hydrochloric), and halogenated media up to 120°C.
Seal Integrity
EPDM: Suitable for water, HVAC, mild alkalis, and ozone treatment; non-compatible with petroleum derivatives.
FKM (Viton): Resistant to high concentrations of inorganic acids, aromatic hydrocarbons, oils, and chlorine solutions.
Connection & Configuration Options
Wafer Pattern: Clamped between companion flanges using standard studs and full-face flat gaskets or integrated O-rings.
Spring-Assist vs. Free-Swing Disc:
- Free-swing disc (gravity return): Preferred for low-pressure drop and vertical upward flow.
- Hastelloy C-276 / PTFE-coated spring assist: Ensures rapid closure under pulsating flow or backpressure conditions to mitigate water hammer.
Spacer Rings: Optional plastic spacer rings available when installing adjacent to butterfly valves or pipe reducers to ensure unobstructed disc swing.
Application-Specific Design Considerations
Flow Velocity Limits: Maintain continuous media flow velocities between 1.0 m/s and 2.5 m/s. Higher velocities cause disc chatter; lower velocities may impede complete seal seating.
Orientation Constraints: For horizontal installations, ensure the valve indicator pin or top marking points vertically upward to guarantee gravity-assisted seating. Avoid downward vertical flow lines.
Media Purity & Solids Content: Best suited for clear fluids and liquids with light suspended solids. High-slurry applications require upstream basket strainers to prevent particulate buildup around the hinge pin.
Applications
Chemical Processing: Handling corrosive acids, bases, sodium hydroxide, and electroplating bath fluids.
Industrial Water & Wastewater: Reverse osmosis (RO) pre-treatment, desalination plants, effluent neutralization, and demineralized water loops.
Semiconductor & Electronics: Distribution lines for Ultrapure Water (UPW) and wet bench chemical distribution systems (PVDF body).
Aquaculture & Marine: Seawater intake, filtration loops, and chlorination feed lines where metal valves suffer pitting.
HVAC & Cooling Systems: Secondary chilled water loops and cooling tower chemical dosing systems.
Quality & Inspection
Each valve batch undergoes strict quality control protocols before dispatch:
Dimensional Verification: 100% CMM and gauge check on body thickness, bolt circle hole pitch, and sealing face concentricity.
Pressure Testing: Every valve undergoes shell pressure testing (1.5× PN) and low-pressure seat leakage testing (1.1× PN) per ISO 5208 Rate A (zero visible leakage).
Material Traceability: Spectrometric chemical verification for raw resin batches and raw material heat certificates available upon request.
Wall Thickness & Mold Inspection: Ultrasonic wall thickness measurements to verify tolerance against stress fractures under line thermal expansion.
OEM / ODM & Customization
We support custom manufacturing tailored to engineering project requirements:
Custom Materials
Glass-reinforced polypropylene (PP-GF) or specialized fluoroelastomer compounds for niche chemical resistance.
Private Labeling & Marking
Laser-etched flow indicators, part numbers, customer logos, and QR code asset tracking on the valve rim.
Custom Cracking Pressures
Factory-calibrated return spring tensions adjusted to specific system hydraulic profiles.
Kitting Services
Pre-assembled packages supplied with custom-matched gaskets, flange adapter rings, and studs.
FAQ
Q: What is the primary advantage of a wafer check valve over a true union swing check valve?
A: A wafer check valve offers a significantly shorter face-to-face dimension and reduced weight. This minimizes pipe stress, saves installation space on modular equipment skids, and reduces total material cost in pipe sizes 2" (DN50) and larger.
Q: Can this plastic wafer check valve be installed in vertical piping?
A: Yes, provided the flow direction is upward. The media force pushes the disc open, and gravity (or spring assist) seats the disc when flow stops. Vertical downward flow lines are not recommended because gravity will keep the disc open.
Q: How do I select between EPDM and FKM seals for chemical service?
A: EPDM is optimal for water, dilute acids, alkalis, and alcohols at moderate temperatures. FKM is required for concentrated acids, organic solvents, aromatic compounds, petroleum traces, and aggressive halogenated chemicals like liquid chlorine.
Q: Are additional gaskets required during flange installation?
A: If the wafer check valve is manufactured with an integrated elastomer O-ring face seal, standard flat gaskets are optional. If the valve face is flat-faced resin, full-face soft EPDM or PTFE gaskets must be used between the valve and mating flanges.
Q: How do I prevent disc interference when mounting directly to a butterfly valve?
A: Installing a wafer check valve directly adjacent to a butterfly valve or pipe reducer can restrict disc movement. Use a dedicated plastic spacer ring between the components to ensure full disc clearance during open-state flow.
Q: What certifications and material compliance documents can be provided?
A: We provide Material Test Reports (MTRs) for plastic resins, ISO 5208 hydrostatic pressure test certificates, and compliance declarations for FDA, REACH, and RoHS upon request prior to order shipment.
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