What functions of Siphon P-Trap?

In this blog post, you’ll read:The good look of a basin is not enough; it should be odor-free. But sometimes wastes create odors that coming back through the basin. That is where siphon traps come into play and stop those smells. In this guide, we are going to introduce everything that you need to know about siphon traps

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The good look of a basin is not enough; it should be odor-free. But sometimes wastes create odors that coming back through the basin. That is where siphon traps come into play and stop those smells. In this guide, we are going to introduce everything that you need to know about siphon traps. So, let’s dive in.

What Is a Siphon Trap?

A siphon trap is a pipe used to forward liquid or wastewater from a basin. In other words, it is a waste pipe that connects the main drain to the basin and allows the water to flow from the basin. However, its main responsibility is to prevent unwanted backflows of water and bad smells.

Different Types of Siphon Traps

You will find different types of siphon traps in the market. For example, p-traps, s-traps, q-traps, bottle traps, etc… But s-traps are no longer available and accepted in many areas. Bottle traps are similar to p-traps. Moreover, the most popular and efficient siphon trap is the p-trap. That is why we will discuss only the p-traps.

Functions of a P-Trap

The reason behind the name Siphon P-Trap is that it looks like the English alphabet “P.” It has two ends, the head of the P and the leg of the P. The hole on the head side is the “inlet” that connects to the basin waste. And the hole on the opposite side or side of the P leg is the “outlet” that connects to the main drain. 

Now, if you look at its parts, you will see the connection between two pipes. One pipe is an incomplete U (known as “Trap”), and the other is a long pipe with a curved head. And both are connected in the middle of the P-trap via coupling nut and washer. In addition, there is another coupling nut and washer on the inlet and a cap or metal cover on the outlet. Also, some traps have a cleanout at their bottom that helps to clean the trap.

Above all, the P-trap has another structure. This one does not look like a P, but it’s also known as siphon p-trap. It has three parts which are the inlet pipe, outlet pipe, and a bottle-type pipe. Both pipes join with the bottle pipe and do the job. However, some call it a bottle trap.

siphon with basin waste drainer
siphon with basin waste drainer

P-Trap Working Principle

The working principle of a siphon p-trap is quite easy but interesting. As you already know, it connects your basin and main drain together so that water can flow from the basin to the drain. Also, it stops the odor coming into your basin from the drain. Now let’s see how it works.

Since it is just a pipe, it will flow out through the siphon trap whenever you pour water into the basin. But the interesting fact is odor preventing. 

If you look underneath the basin, you will see the p-trap set horizontally. If you pour water, it will enter the trap or in the U zone through the inlet. It stays there and does not move due to gravityWhen the water reaches a certain level, it crosses the U zone and goes to the outlet. This is called overflow.

After the first flow of water, a certain amount of water is always in the U zone. However, every time water flows, it is replaced with new water. Since the U pipe of the trap stays full the whole time, nothing comes back. Therefore, p-trap prevents odor and unwanted backflows.

Which Material Is Better For Siphon?

Since some water always stays in the trap so that low-quality materials can be easily damaged. In the siphon traps manufacturing world, manufacturers use a wide variety of materials. Those are brass, stainless steel, abs, and sometimes plastic

Each material has its unique abilities, but brass is the best and most efficient material for p-traps. This is because the durability and resistance of brass are way better than the other materials. 

siphon trap
siphon trap

Uses of P-Traps

Nowadays, p-traps are most commonly used in washbasins. Also, they are doing great work in the kitchen sinks and toilets. This is because kitchen sinks and toilets are a great source of odors. But this problem no longer occurs after using the siphon traps.


It may look like a simple waste pipe but offers many benefits. Such as:

1 First of all, siphon does not allow the stench to come into the room. Also, it prevents the water from flowing back.

2 Offers a very simple installation process, and anyone can do it.

3 Allows for easy cleaning and does not require regular maintenance.

4 Comes with different materials and looks that express a modern feeling.

Low price, affordable to anyone.

Siphon Trap Buying Guide

If you are not careful when buying a siphon, you may face various problems in the future. So, consider these things before buying it:

· First of all, choose which type of siphon trap you want for your basin or toilet. Remember, the P Trap is the best and most widely used siphon in the world.

· The material is an important thing. So, choose pure brass as the primary material. 

· Different types of finishes are also available. But no finish can beat Chrome Plating for a siphon.

· Sometimes, siphon pipes do not fit the measurements of your basin. To avoid this problem, take the measurements first and then buy the right size siphon.

toilet trap
toilet trap

Check for leaks and defects.

You can avoid future problems by following these tips. But there is another way to do it. That is, buy siphon traps from a good and reputable supplier like Hofen. Yes, we, Hofen, have been making high-quality brass siphon traps for years… and supplying those around the world with a defect rate of about 0. Check our products and contact us for anything you want to know about us or our products.

Siphon traps are working great in our daily lives, and we don’t even notice them. But you will definitely see them from now on, haha. Anyway, I hope this article helps you a lot to understand a siphon. Don’t forget to follow our other posts on different plumbing ideas. Good Day…

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