P-traps are known for their reliability and efficiency in maintaining a water seal, which helps to prevent
A P-trap is shaped like the letter “P” and is commonly used for sinks, showers, and bathtubs. On the other hand, an S-trap has a shape resembling the letter “S” and is typically used for floor drains or fixtures where a P-trap cannot be installed.
The S-Trap's Major Flaw
The “s” design could cause a water siphon, removing the water built up in the curve, opening the seal, and allowing sewer gas to pass through. This flaw is whys-traps are no longer allowed in plumbing code and should be replaced if you have one.
A specialized fitting called a p-trap creates a powerful barrier that stops sewer gas and odor from entering your home. The trap is employed in any plumbing system that uses a drain and accepts sanitary waste from tubs, showers and sinks.
While S traps were once popular, especially for ground floor installations due to their specific design and water flow characteristics, they have some significant drawbacks: They can be prone to siphoning, which means the water seal can be lost, allowing sewer gases to enter the home.
Answer: The biggest risk of an S trap is siphoning, which can cause the trap to lose its water seal. This allows dangerous sewer gases to enter your home, creating potential health risks and unpleasant odors.
Code Compliance
S traps are prohibited throughout the United States by the International Plumbing Code. They have been banned since 2006 because of the siphonage hazard. It could cause the water seal to escape the conduit.
P traps that are either too deep or too long can collect too much water to the point that any debris that passes through the drain won't get washed away by the pressure of the water draining from the sink or tub. This will inevitably lead to more frequent clogs that are harder to remove.
The main purpose of a P-trap is to trap noxious sewer gases inside the wastewater system so that they can't rise back up through the drain, and it is the shape of the trap that makes this possible. Running your sink obviously flushes water through the trap and down into the drain line.
The P-trap has the important job of preventing sewer gasses from making their way into your bathroom. Although you can't really see the shower trap, it is a super important part of your plumbing system. Does a shower drain need a trap? In short, yes, every shower drain in the United States must have a trap or P-trap.
We can use a trap to catch any water or other fluids not meant to be in the basin or the drain. P-traps are typically used in kitchens as they can handle cold water. In contrast, S-traps are more suited for bathrooms because they can only handle warm water.
Pros of Toilet P-Traps
The additional vent pipe most P-trap toilets require further lower the risk of gas siphoning. Most modern plumbing codes require P-trap toilets for residential installations.
What is an S-trap? S-traps are a type of plumbing trap that blocks sewer gases in sinks and other plumbing fixtures. The S-shaped pipe configuration traps wastewater before it drains to the sewer line, creating a water seal that prevents gases from flowing up through the drain.
Do you know the proper way to size a P trap on an HVAC unit? The pull of the water to the drain has to exceed the sucking of the supply fan (“negative pressure”). Rule of thumb… add 2.5” to the static pressure before the fan (return and internal to the unit) and that's the long end (closer to the drain of the unit.
While S-traps may still be found in older properties, upgrading to P-traps ensures compliance with modern standards and reduces the risk of sewer gas intrusion. Regular maintenance and professional consultations are key to keeping your bathroom plumbing in optimal condition.
P-traps need vents
While the traps are doing their job of keeping the sewer gases out of your home, vents perform 2 functions. 1 – They give the sewer gases a place to vent, so they do not build pressure inside your sewer lines. 2 – They prevent siphoning of the water out of the trap.
They are designed to constantly hold water in the drain to prevent sewer gas from escaping into the house. While sewer gases may contain noxious odors and smell terrible, they can also be explosive and poisonous. Ensuring that your P-trap has enough water will keep things running smoothly.
With origins dating back to the early 1900s, P-traps are often installed on air conditioner condensate drains to seal against air leaks. The intended purpose of the p-trap is to allow condensate to flow from the equipment while simultaneously preventing air leakage into or out of the unit.
The vertical distance from the fixture outlet to the trap weir shall not exceed 24 inches (610 mm), and the horizontal distance shall not exceed 30 inches (610 mm) measured from the centerline of the fixture outlet to the centerline of the inlet of the trap.
In some cases, an improperly installed p-trap can also lead to clogs. The p-trap is designed to trap debris and prevent it from entering your plumbing system, but if it's not installed correctly, debris can build up and cause a blockage.
Use the Fixture Regularly
Regular usage can prevent P-traps from drying out. Make it a habit to run water through infrequently used drains at least once a week.
The P-trap is now the standard since the S-trap was deemed ineffective and prohibited in new construction under the Universal Plumbing Code. The S-trap was found to be prone to siphoning and drying out, which leaves the apparatus ineffective.
Plumbing codes expressly prohibit the use of double traps.
An S-shaped trap is also known as an S-bend. It was invented by Alexander Cumming in 1775 but became known as the U-bend following the introduction of the U-shaped trap by Thomas Crapper in 1880.