UPVC Reducer Coupler
UPVC Reducer Coupler fittings are used to connect two UPVC pipes of different diameters while maintaining a clean, aligned flow path. Industries support projects that need reliable size transitions in chemical distribution, irrigation, drainage, and industrial utility lines. A properly selected UPVC reducer coupler helps minimize leakage risks, improves joint stability, and simplifies layout changes when a line moves from a main header to a smaller branch. With consistent dimensions and smooth internal bore, reducer couplers help maintain flow efficiency and reduce turbulence compared to improvised transitions. Contractors and maintenance teams also make repairs faster by allowing direct coupling of available pipe sizes without redesigning the entire run.
A UPVC reducer coupler works by providing two socket ends with different internal diameters inside one fitting body. The larger side accepts the main pipe, and the smaller side accepts the reduced pipe size. Installation typically uses solvent cement welding for uPVC systems: both pipe ends are cut square, deburred, cleaned, and dry-fitted to confirm insertion depth. Primer and solvent cement are applied to the pipe and coupler sockets, then the pipes are inserted fully with a quarter-turn twist to spread cement evenly. The joint cures into a single, fused connection. For threaded or special-purpose systems, reducer couplers may use threaded ends or gasketed push-fit designs, but the goal remains the same: a secure transition that stays aligned under operating conditions.
- Chemical Resistance
- Low Maintenance Requirement
- Low Thermal Conductivity
- Long Service Life
- Easy Installation
- Corrosion Resistance
UPVC Reducer Coupler Details
ID-1: Internal Diameter of the bottom opening.
OD-1: Outer Diameter of the bottom body.
WT-1: Wall Thickness of the bottom section.
SL-1: Socket Length (insertion depth) for the bottom.
ID-2: Internal Diameter of the top opening.
OD-2: Outer Diameter of the top body.
WT-2: Wall Thickness of the top section.
SL-2: Socket Length (insertion depth) for the top.
H: Total Height of the entire component.
| Size (Inch) | ID-1 (mm) | OD-1 (mm) | WT-1 (mm) | SL-1 (mm) | ID-2 (mm) | OD-2 (mm) | WT-2 (mm) | SL-2 (mm) | H (mm) |
| ¾ x ½ | 26.97 | 34.79 | 3.91 | 25.40 | 21.64 | 29.10 | 3.73 | 22.23 | 56 |
| 1 x ½ | 33.78 | 42.88 | 4.55 | 28.58 | 21.64 | 29.10 | 3.73 | 22.23 | 66 |
| 1 x ¾ | 33.78 | 42.88 | 4.55 | 28.58 | 26.97 | 34.79 | 3.91 | 25.40 | 65 |
| 1¼ x ½ | 42.55 | 52.25 | 4.85 | 31.75 | 21.64 | 29.10 | 3.73 | 22.23 | 69 |
| 1¼ x ¾ | 42.55 | 52.25 | 4.85 | 31.75 | 26.97 | 34.79 | 3.91 | 25.40 | 68 |
| 1¼ x 1 | 42.55 | 52.25 | 4.85 | 31.75 | 33.78 | 42.88 | 4.55 | 28.58 | 68 |
| 1½ x ½ | 48.72 | 58.88 | 5.08 | 34.93 | 21.64 | 29.10 | 3.73 | 22.23 | 74 |
| 1½ x ¾ | 48.72 | 58.88 | 5.08 | 34.93 | 26.97 | 34.79 | 3.91 | 25.40 | 76 |
| 1½ x 1 | 48.72 | 58.88 | 5.08 | 34.93 | 33.78 | 42.88 | 4.55 | 28.58 | 75 |
| 1½ x 1¼ | 48.72 | 58.88 | 5.08 | 34.93 | 42.55 | 52.25 | 4.85 | 31.75 | 74 |
| 2 x ½ | 60.78 | 71.86 | 5.54 | 38.10 | 21.64 | 29.10 | 3.73 | 22.23 | 85 |
| 2 x ¾ | 60.78 | 71.86 | 5.54 | 38.10 | 26.97 | 34.43 | 3.73 | 25.40 | 85 |
| 2 x 1 | 60.78 | 71.86 | 5.54 | 38.10 | 33.78 | 42.88 | 4.55 | 28.58 | 85 |
| 2 x 1¼ | 60.78 | 71.86 | 5.54 | 38.10 | 42.55 | 52.25 | 4.85 | 31.75 | 83 |
| 2 x 1½ | 60.78 | 71.86 | 5.54 | 38.10 | 48.72 | 58.88 | 5.08 | 34.93 | 83 |
| 2½ x 2 | 73.56 | 87.58 | 7.01 | 44.45 | 60.78 | 71.86 | 5.54 | 38.10 | 104 |
| 3 x 2 | 89.31 | 105.55 | 16.24 | 48.63 | 60.78 | 88.54 | 27.76 | 48.93 | 104 |
| 3 x 2½ | 89.51 | 104.75 | 7.62 | 47.63 | — | — | — | — | — |
| Parameter | Description |
| Product Name | uPVC Reducer Coupler |
| Material | Unplasticized Polyvinyl Chloride (uPVC) |
| Color | Grey / White (as per standard) |
| End Connection | Socket × Socket (Solvent Weld) |
| Manufacturing Process | Injection Moulded |
| Jointing Method | Solvent Cement |
| Pressure Rating | PN6 / PN10 / PN16 |
| Temperature Range | 0°C to 60°C |
| Surface Finish | Smooth, glossy |
| Standards | ASTM D2466 / IS 7834 / ISO 1452 / DIN 8063 |
| Application | Irrigation, chemical lines |
Corrosion Resistant – Immune to rust, scaling, and chemical corrosion; suitable for chemical, wastechemical, and many chemical lines.
Smooth Internal Bore – Low friction loss and minimal pressure drop, improving flow efficiency.
High Mechanical Strength
Rigid, impact-resistant construction with good tensile and compressive strength.
Excellent Chemical Resistance – Resistant to acids, alkalis, salts, and most industrial chemicals.
Lightweight Construction – Easier handling, transport, and installation compared to metal fittings.
Leak-Proof Solvent Cement Joint – Designed for solvent welding, ensuring strong, permanent, and leak-free connections.
Dimensional Accuracy – Precision molded for consistent wall thickness and proper socket depth.
Long Service Life – Non-aging material with high resistance to environmental degradation.
Low Maintenance – No painting, coating, or corrosion protection required.
Pressure Rated – Suitable for pressure applications as per relevant standards (e.g., PN6, PN10, PN16).
Temperature Resistance – Suitable for cold chemical and low-temperature fluid systems (typically up to 60°C).
Electrical Insulation – Non-conductive material, safe for electrical and underground applications.
Eco-Friendly & Non-Toxic – Lead-free and suitable for potable chemical systems.
Standard Compliance – Manufactured as per ASTM / ISO / DIN / BS / IS standards (depending on region).
ASTM uPVC Reducer Coupler – Schedule 40
| Reducer Size (in) | Max Working Pressure (psi) | Max Working Pressure (bar) |
| 1 × ½ | 450 | 31 |
| 1½ × 1 | 330 | 23 |
| 2 × 1 | 330 | 23 |
| 3 × 2 | 280 | 19 |
| 4 × 2 | 280 | 19 |
| 4 × 3 | 260 | 18 |
| 6 × 4 | 220 | 15 |
| 8 × 6 | 180 | 12 |
ASTM uPVC Reducer Coupler – Schedule 80
| Reducer Size (in) | Max Working Pressure (psi) | Max Working Pressure (bar) |
| 1 × ½ | 850 | 58 |
| 1½ × 1 | 630 | 43 |
| 2 × 1 | 630 | 43 |
| 3 × 2 | 400 | 28 |
| 4 × 2 | 400 | 28 |
| 4 × 3 | 370 | 26 |
| 6 × 4 | 320 | 22 |
ISO / Metric uPVC Reducer Coupler (PN Rating)
| PN Class | Max Working Pressure @ 20 °C | Typical Applications |
| PN6 | 6 bar (87 psi) | Drainage, low pressure |
| PN10 | 10 bar (145 psi) | Chemical supply |
| PN16 | 16 bar (232 psi) | Industrial / irrigation |
| PN20 | 20 bar (290 psi) | High-pressure systems |
Temperature Derating Table (uPVC)
| Temperature (°C) | Pressure Factor |
| 20–23 | 1.00 |
| 30 | 0.88 |
| 40 | 0.62 |
| 50 | 0.38 |
| Property | Typical Value | Test Method / Standard |
| Material | Unplasticized Polyvinyl Chloride (uPVC) | ASTM D1784 |
| Density | 1.38 – 1.45 g/cm³ | ASTM D792 |
| Specific Gravity | 1.38 – 1.45 | ASTM D792 |
| Color | Grey / White | Manufacturer Standard |
| Surface Finish | Smooth, glossy | Visual |
| Hardness (Shore D) | 80 – 85 | ASTM D2240 |
| Tensile Strength | ≥ 45 MPa | ASTM D638 |
| Flexural Strength | ≥ 80 MPa | ASTM D790 |
| Modulus of Elasticity | 2.5 – 3.2 GPa | ASTM D638 |
| Impact Strength (Izod, Notched) | ≥ 2.5 kJ/m² | ASTM D256 |
| Vicat Softening Temperature | ≥ 80°C | ASTM D1525 |
| Coefficient of Thermal Expansion | 6.0 – 8.0 × 10⁻⁵ /°C | ASTM D696 |
| Thermal Conductivity | 0.14 – 0.16 W/m·K | ISO 8302 |
| Water Absorption (24 hrs) | ≤ 0.5% | ASTM D570 |
| Electrical Conductivity | Non-conductive | IEC 60093 |
| Flammability | Self-extinguishing | UL 94 V-0 / V-1 |
Custom Product Manufacturing Available
If you are searching for customized product designs that meet your requirements, don’t worry. Petron Thermoplast also offers custom product manufacturing services to meet the unique needs of various industries. Work with our expert engineers to create custom designs suited for your application.
Benefits of UPVC Reducer Coupler
Reducing from a main UPVC header to a smaller distribution line
Irrigation laterals where branch lines require smaller pipe diameters
Drainage and rainwater downpipe transitions between sizes
Utility chemical lines in residential, commercial, and light industrial projects
Quick repair work when replacing a damaged section with an available pipe size
Clean size transition without extra adapters or multiple joints
Improves alignment and reduces stress concentration at the diameter change
Supports faster installation and simpler site layout modifications
Helps reduce turbulence compared to abrupt, improvised transitions
Types & Connections of UPVC Reducer Coupler
Types of UPVC Reducer Couplers
- Concentric UPVC Reducer Coupler
Connects two different pipe sizes with a common center line. Commonly used in vertical pipelines and general plumbing. - Eccentric UPVC Reducer Coupler
Has offset center lines to keep the top or bottom level constant. Used in horizontal pipelines to avoid air pockets. - Socket × Socket UPVC Reducer Coupler
Both ends have sockets to join two pipes of different diameters using solvent cement. - Socket × Spigot UPVC Reducer Coupler
One end has a socket and the other a spigot, allowing connection flexibility where space is limited. - Threaded UPVC Reducer Coupler
Used where threaded connections are required for easy installation or dismantling. - Pressure UPVC Reducer Coupler
Designed to withstand high-pressure applications like water supply systems. - Drainage (Non-Pressure)UPVC Reducer Coupler
Used in low-pressure or gravity-flow drainage systems.
Connection Method (Step-by-Step)
- Pipe Cutting
Cut both pipes square to the axis
Remove burrs and sharp edges - Dry Fit Check
Insert pipes into reducer coupler without cement
Ensure proper depth and alignment - Surface Cleaning
Clean pipe ends and coupler sockets
Use uPVC cleaner or dry cloth - Apply Solvent Cement
Apply evenly on pipe outside and coupler socket inside
Use recommended uPVC solvent cement - Joint Assembly
Push pipe fully into socket
Give a quarter-turn for even cement distribution - Holding Time
Hold joint for 30–60 seconds
Prevent movement during initial setting - Curing Time
Allow curing as per cement manufacturer
Typically 24 hours before pressure testing
Common uses of UPVC Reducer Coupler
Joining rebars of two different diameters (e.g., 25mm to 20mm)
Joining rebars of two different diameters (e.g., 25mm to 20mm)
Reducing bar diameter for structural design optimization
Enabling easier handling of upper rebars in vertical structures.
Enhancing seismic performance in transition zones
Providing strong, code-compliant mechanical splices
Why Choose Petron Thermoplast?
Custom combination available(32mm to 25mm, 25mm to 20mm, etc).
Tested for tensile, fatigue, and dynamic loads
Bulk production capabilities with on-time delivery
Corrosion-resistant coating for durability
Preferred supplier for top civil infrastructure companies
UPVC Pipe Fittings
We offer UPVC Pipe Fittings products in all standard sizes and provide complete customization options to meet your specific project requirements across our entire product range.
