75/50mm Metric Reducing Coupling
SKU: PVC-RDCPLG-7550
- Linear Reducer Design: Connects a 75mm metric pipe inline with a 50mm metric pipe, maintaining a straight, high-integrity plumbing run.
- Double Slip Sockets: Features smooth female slip sockets on both ends, designed for permanent, leak-free solvent-welded joints.
- Aquarium-Grade Dark Gray Finish: Neutral industrial aesthetic matches professional sumps, reef reactors, and high-end cabinetry manifolds.
- 100% Reef Safe Construction: Free from volatile heavy metal stabilizers and harmful plasticizers, making it safe for delicate marine corals and invertebrates.
- Heavy-Wall Structure: Molded from premium unplasticized PVC (uPVC) to handle high-pressure pump loops and resist structural line vibration.
CoralVue 75/50mm Metric Reducing Coupling
The CoralVue 75/50mm Metric Reducing Coupling (SKU: PVC-RDCPLG-7550) is a premium, inline fluid management component engineered to bridge different pipe sizes within tight reef cabinet environments. When building advanced marine aquariums, large commercial aquaculture systems, or multi-tank custom manifolds, transitioning from larger master drainage lines or primary gravity overflows down to standard 50mm sump runs is frequently required. Unlike flush bushings that sit inside other fittings, this standalone inline coupling connects two separate pipe sections end-to-end, keeping your hard-plumbed runs perfectly aligned and clean.
Molded to precise aquaculture tolerances, this dark gray coupling features a 75mm female slip socket on one side and a 50mm female slip socket on the other. By solvent welding this fitting directly between 75mm and 50mm metric rigid pipes, you achieve a highly reliable transition. The interior walls feature a smooth, sweeping taper that minimizes friction and localized turbulence, keeping your system's flow rates running as efficiently as possible.
Key Features
Molded Internal Pipe Stops: Built-in landing shoulders inside both sockets prevent over-insertion of the pipe, ensuring a structurally sound, consistent solvent weld.
Swept Transitional Bore: The internal taper reduces flow restriction and prevents organic detritus from settling inside the fitting.
uPVC Composition: Offers exceptional chemical and corrosion resistance against highly concentrated saltwater environments.
(Note: This retail SKU contains (1) individual standalone CoralVue 75mm to 50mm Reducing Coupling. Solvent primers, cements, and rigid piping are sold under separate product categories).
What’s Included:
(1) CoralVue PVC-RDCPLG-7550 75/50mm Metric Reducing Coupling
Technical Specs:
Official Manufacturing Title: 75mm x 50mm Female Slip Reducing Coupling
SKU / Factory Part Identifier: PVC-RDCPLG-7550
Fitting Side A (Large Socket): Accepts standard 75mm Metric rigid pipe (Female Slip)
Fitting Side B (Small Socket): Accepts standard 50mm Metric rigid pipe (Female Slip)
Primary Material Composition: Heavy-Wall Unplasticized Polyvinyl Chloride (uPVC)
Maximum System Pressure Rating: Up to 150 PSI continuous operational threshold
Maximum Thermal Operating Limit: 140°F (60°C) continuous service capacity
Primary Injection Color Finish: Dark Industrial Gray
While most of our equipment carries a one-year manufacturer's warranty, consumable products like fish and coral foods are not covered under traditional warranty terms due to their perishable nature and varied storage conditions. However, we fully stand behind the quality of every product we sell. If you experience any issues with your food purchase shortly after receiving it, such as concerns about freshness, packaging integrity, or product quality, please contact us at [email protected]. We're committed to making it right and will work with you to resolve any problems quickly and fairly.
- Ensure both the 75mm and 50mm rigid pipes are cut cleanly at a true 90-degree angle and deburred. Clean both pipe ends and the coupling's inner sockets.
- Apply a thin, even layer of PVC primer to the inside of the coupling's 75mm socket and the outside of the 75mm pipe.
- While wet, apply PVC solvent cement over both primed surfaces and insert the 75mm pipe fully into the socket, rotating it 1/4 turn to spread the glue. Hold firmly for 15 seconds.
- Repeat the priming and gluing steps for the coupling's 50mm socket and the 50mm metric pipe.
- Insert the 50mm pipe fully until it hits the internal landing shoulder, and hold firmly for another 15 seconds.
- Allow a full 24-hour cure time before introducing high-pressure saltwater flow to guarantee the integrity of the chemical welds.
Pro Tips:
- Do Not Attempt to Glue Imperial Pipe Directly Into This Metric Fitting.
CRITICAL AQUARIUM PLUMBING DESIGN TIP: This reducing coupling is engineered to exact metric dimensions. The slip ports accept only standard 75mm and 50mm metric rigid pipes. Do not attempt to force standard 2-1/2" or 1-1/2" domestic Schedule 40 or Schedule 80 pipe into the sockets. Doing so will result in a sloppy, leaking connection that will fail under pressure.
- Use Inline Couplings for Clean, Serviceable Runs. When running a dedicated line from a main commercial manifold or large drainage setup down to a standard 50mm run, using an inline reducing coupling keeps the pipe straight and neat. It also makes it much easier to clip the plumbing against your cabinet or system walls using standard metric pipe clamps, as the run remains concentric and parallel.
- Always Wipe Away Excess Glue Squeeze-Out. When pushing the pipes into the sockets, a small bead of excess solvent cement will be forced out of the joint. Always wipe away this excess glue from the pipe interface with a clean cloth to ensure a neat, professional look inside your aquarium cabinet.



