P-Trap (Trap) - Component for Drainage Systems

Product Specifications

Technical details and manufacturing context for Trap (P-Trap)

Definition

A P-trap is a U-shaped pipe section used in drainage systems to hold a small amount of water, creating a seal that blocks sewer gases and odors from backing up into living or working spaces. It is an essential component in sinks, toilets, showers, and floor drains, serving as the first line of defense against air contamination from sewage systems. The trap is typically made from materials such as PVC, ABS plastic, stainless steel, brass, or cast iron, each offering different properties in terms of corrosion resistance, durability, and cost. Common nominal diameters range from 32 to 50 mm for sink and basin traps, with wall thicknesses between 1.5 and 3.0 mm. Operating pressure typically ranges from 0.1 to 0.6 MPa, and operating temperature from -20°C to 95°C; sustained temperatures above 95°C may deform plastic traps. The water seal depth is critical, with a minimum of 50 mm to prevent siphonage, and typical depths range from 50 to 75 mm. Leakage rate must be zero under hydrostatic testing. For stainless steel traps, a common material grade is 304 per ASTM A240. Surface finish ranges from 0.8 to 1.6 µm Ra, and weight varies from 0.3 to 1.2 kg depending on material and size. Connections are typically threaded per ISO 228-1, with sizes from G1/2 to G2. These values are directory reference ranges and must be confirmed for the specific model and application with the legal manufacturer or supplier. Standards listed are for procurement and verification reference only, not proof of certification or compliance.

Working Principle

The P-trap operates on a simple hydraulic principle: after water flows through the drain, a portion remains in the curved section of the pipe, creating a water barrier that prevents gases from passing through while allowing liquids and solids to continue downstream. This water seal must be maintained to function properly. If the trap dries out, sewer gases can enter the building. The depth of the water seal, typically 50-75 mm, is designed to resist siphoning and maintain an effective barrier under normal drainage conditions.

Common Materials

PVC, ABS plastic, Stainless steel, Brass, Cast iron

Technical Parameters

Parameter	Typical range	Notes & selection driver
Nominal Diameter	32–50 mm	Common sizes for sink and basin trapsISO 228-1
Wall Thickness	1.5–3.0 mm	Affects mechanical strength and durabilityISO 228-1
Operating Pressure	0.1–0.6 MPa	Typical for gravity drainage systems
Operating Temperature	-20–95 °C	Sustained above 95°C may deform plastic traps
Water Seal Depth	50–75 mm	Minimum 50 mm to prevent siphonageEN 274
Leakage Rate	0.0 L/min	Must be zero under hydrostatic test
Material Grade	304	Stainless steel for corrosion resistanceASTM A240
Surface Finish	0.8–1.6 µm Ra	Smoother finish reduces foulingISO 4287
Weight	0.3–1.2 kg	Depends on material and size
Connection Type	G1/2–G2 inch	Threaded connections per ISO 228ISO 228-1

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Components / BOM

Inlet connection Part
Receives wastewater from the fixture drain

Material: varies
U-bend section Part
Holds the water seal that blocks sewer gases

Material: varies
Outlet connection Part
Connects to the drainage pipe system

Material: varies
Cleanout plug Part
Provides access for cleaning and maintenance

Material: varies

Applied To / Applications

This component is essential for the following industrial systems and equipment:

Drainage System

View system integration details

Manufacturers of Trap (P-Trap)

Manufacturer profiles associated with Trap (P-Trap).

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Frequently Asked Questions

What is the purpose of a P-trap?

A P-trap holds water to create a seal that prevents sewer gases and odors from entering a building through the drainage system, while allowing wastewater to flow through.

What materials are commonly used for P-traps?

Common materials include PVC, ABS plastic, stainless steel, brass, and cast iron. Each material offers different properties in terms of corrosion resistance, durability, and cost.

What is the minimum water seal depth for a P-trap?

The minimum water seal depth is 50 mm to prevent siphonage, with typical depths ranging from 50 to 75 mm as per EN 274.

How do I verify the specifications of a P-trap?

Always confirm model-specific values such as nominal diameter, wall thickness, operating pressure, temperature range, and material grade with the legal manufacturer or supplier, as the listed values are directory reference ranges.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records.

Preliminary Technical Classification

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pressure:	Atmospheric to 10 psi (0.7 bar) - non-pressurized drainage system
flow rate:	0.5 to 25 GPM (1.9 to 94.6 LPM) typical residential/commercial
temperature:	0°C to 100°C (32°F to 212°F)
slurry concentration:	Up to 5% solids by volume for standard designs

Trap (P-Trap)

Product Specifications

Applied To / Applications

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