As a Civil Engineer, one’s knowledge of plumbing should not be limited to textbooks or left to the plumber. It is essential for the civil engineer to know the right type of trap used for the specific water fixture. So here in this article, comparisons of the S-trap and P-trap are made for your interest.
What is S-Trap?
S-trap looks like the letter “S” which is why the name S-trap is given. The trap is intended to outlet the wastewater from the wash basin, bathtub and kitchen sink keeping the unwanted foul smells out. This is achieved by containing water in the “S” shape of the trap. This water acts as a barrier from entering toxic gases into the outer environment (house) and inner environment (pipe network).
What is P-Trap?
Unlike the S-trap, the P-trap also looks like the letter “P” or it is a “U” shape pipe connected to the pipeline. The functionality of the P-trap is the same as that of the S-trap. The advantage of such a trap is that it has no tendency to siphon out the water. It does not even mean that the retention of water in the trap is prolonged, but the water can dry out if the trap is not used for a more extended period.
Difference Between S-Trap and P-Trap
The comparison made between these two traps is on the basics of technical application and functionality. Although they have the same functionality, they also have some differences which we will see under a subheading.
1. Structure
The S-trap is made to look like the letter “S” but is in the lying/resting position as shown in the picture below. Also, the head is connected to the sink, tub, or WC pan. The other end of the opening is connected to the drain pipe, the water outlet. In comparison, the P-trap is the same as the letter “P” or simply a “U” shape trap and also in the slipping position like the S-trap. The head is connected to the sink, tub, or WC pan. The tail opening is connected to the drain pipe. The P-shaped head contains the water.
2. Functionality
Both the traps have the same functionality, which is to provide a connecting route to the drain pipe and water fixture (under a sink or tub). However, the P-trap is gaining more popularity than the S-trap in terms of a better barrier from entering noxious gases. In the case of the S-trap, it is likely to wash out all the water barriers in the trap when excess water is poured through it and create an air gap through which a foul smell can escape. Whereas, in the P-trap, the air gap is not created even with the use of excess water.
3. Placement
This is the subject of agreement as some may use one type of trap in all kinds of connections or interchange the connection and trap. However, through the studies and lifelong user experience, it was found that P-traps are better when connected to intensive use of water is present. Such an example is the sink in the restaurant’s kitchen, hospital, and college cafeteria. However, they are also installed in the water closet and bathtub of a residential building replacing the S-trap. S-trap also comes with a built-in water closet in the toilet.
Also, read: Types of Traps: Functions And Used In Plumbing
FAQs:
Q: What is S-Trap?
Answer: The S-trap is so called because of its shape which looks like the letter “S” and is connected to a pipeline to prevent the rise of sewer gases into the sink or other water fixtures.
Q: What is P-Trap?
Answer: P-trap also looks like the letter “P” or it is a “U” shape pipe which is connected to a pipeline and contains a water barrier which prevents the rise of fuel and harmful smells in the house. These foul and harmful gases are sewer gases.
Q: Why is P-Trap preferred over S-Trap?
Answer: These days, the P-trap is preferred over the S-trap because the only advantage is that the P-trap can hold the water barriers much longer than the S-trap.
