How To Use Eccentric Reducers?

Eccentric reducer is a special pipe fitting that connects two pipes of different sizes, but unlike a regular reducer, which is perfectly round and centered, the eccentric reducer looks uneven or lopsided. Its top edge is flat and straight, while its bottom edge slopes down. The main purpose of eccentric reducer is to keep the bottom of the pipes perfectly level when you connect a larger pipe to a smaller one. This is very important in pipes that carry liquids, especially water.

Why? Because if the pipe bottoms aren't level, air bubbles can get trapped at the top of the pipe where the size changes. Trapped air can cause problems like loud noises, vibrations, the pump not working right, or even damage over time. So, we use eccentric reducers a lot in projects that involve moving water or other liquids where keeping the pipes level and avoiding air pockets is critical. Eccentric reducers help the liquid flow smoothly without air getting stuck.

Eccentric Reducer Applications

Water Pipes in Buildings and Cities

Eccentric reducers are often used in big water pipes that run sideways under streets or inside buildings. Their main job here is to stop air bubbles from getting stuck when the pipe changes size. Air trapped in pipes can block water flow or cause banging noises. The flat top of the eccentric reducer keeps the pipe's highest point level. This lets air flow smoothly out through special valves instead of collecting. It helps the water move reliably and quietly through the system.

Heating and Cooling Systems (HVAC)

HVAC systems use pipes to carry hot water, cold water, or steam to heat or cool buildings. These pipes often need to slope slightly so water can drain out completely when the system is turned off. An eccentric reducer is used when these sloped pipes connect to a pump or a piece of equipment. Its straight bottom edge lets the pipe keep its smooth, constant slope all the way to the connection. This prevents water from pooling in low spots, which could freeze and crack pipes in winter or cause rust.

Pumps for Liquids

Pumps are machines that push liquids like water or chemicals through pipes. It's very important that liquid flows smoothly into the pump's suction inlet. If air or vapor bubbles get sucked into the pump, it can damage the spinning part inside (the impeller) and make the pump noisy and weak. An eccentric reducer is placed right before the pump inlet when connecting a bigger pipe to the smaller pump. It is installed with the flat side on top. This keeps the top of the pipe straight, preventing air pockets from forming above the inlet. This ensures only liquid enters the pump, helping it work well and last longer.

Drains for Liquids

In factories or places where liquids flow along the bottom of large, sideways pipes, like drains or sewers, eccentric reducers are used to change the pipe size. They are put in with the slanted (tapered) side at the top and the flat side at the bottom. This keeps the very bottom of the pipe perfectly level where the liquid flows. It stops solid stuff (like dirt or bits of material) from getting caught on a ledge inside the pipe when the size changes. This helps the liquid and anything in it drain away without clogging.

Fuel and Oil Pipes

In systems moving fuel, oil, or other liquids that must not leak, eccentric reducers help keep pipes completely full. When pipes change size sideways, an eccentric reducer with its flat side on top is used. This avoids creating a high spot where air or gas could gather. Trapped air or gas can cause problems like uneven flow or pressure changes. Keeping the top flat ensures any air can easily escape through vents, making the liquid flow steadier and safer.

How To Use Eccentric Reducer

Understand Why Direction is Crucial

Before touching the reducer, know this: which way it points is the MOST IMPORTANT part. An eccentric reducer is not the same all around. It has one flat side and one slanted side. You MUST decide if the flat side needs to point UP or DOWN. This depends ONLY on what the pipe is doing. Putting it the wrong way up will cause big problems later. For pipes full of liquid under pressure, the flat side almost always goes UP. This stops air bubbles from getting trapped. For pipes where liquid drains along the bottom by gravity, the flat side almost always goes DOWN. This keeps the bottom smooth so stuff doesn't get stuck. Figuring out the correct direction is the absolute most critical step.

Get the Pipe Ends Ready

Make sure the ends of the big pipe and the small pipe are clean and ready. They need to be cut straight, not crooked. Use a file or sandpaper to remove any rough edges, dirt, or rust where the reducer will connect. This helps make a tight, leak-proof seal. If you are welding the pipes, you might need to grind a special angled edge/bevel on the pipe ends first. Clean pipes are crucial for preventing leaks.

Position the Reducer with the Correct Orientation

Hold the eccentric reducer between the big pipe end and the small pipe end. Now, carefully turn (rotate) the reducer. You must point the flat side the right way, either UP towards the sky or DOWN towards the ground—based on what you decided in Step 1. Look at it carefully. Double-check that it's facing the correct direction before you connect anything. If the pipe is supposed to slope, also make sure the very bottom inside edge of the big pipe, the reducer, and the small pipe form one smooth, straight, slanted line.

Connect the Reducer Securely to the Pipes

Now, attach the reducer to the big pipe and the small pipe using your chosen method. If using flanges, put a soft gasket between each flange face and the reducer, then bolt them together tightly and evenly. If using threads, wrap special pipe thread tape or paste around the male threads, then screw the reducer onto both pipe ends firmly, but don't overtighten and crack it. If using welding, a trained welder must carefully weld the reducer to both pipe ends, ensuring strong, leak-free joints. Making strong, sealed connections at both ends is essential for the pipe system to work safely and not leak.

Always Work Safely

Never forget safety. Always wear safety glasses to protect your eyes, especially when cutting, grinding, or welding. Wear strong gloves to protect your hands from sharp edges. Make absolutely sure the pipe system is NOT under pressure (no liquid or gas flowing) and is safe to work on before you start. If working high up, use proper ladders or scaffolds. Follow all safety rules for the tools and methods you are using.

Conclusion

An eccentric reducer is placed before pump inlets to stop air from entering and damaging the pump, ensuring only liquid flows in. In drains and sewers, they keep the bottom smooth so solids like dirt don't get stuck and cause clogs.