Drain Fitting Bypass for Negative Pressure Seal Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing drain fittings with odor traps struggle to maintain a reliable sealing water level due to negative pressure in drain lines, which can lead to ineffective odor trapping, especially in low-height installations that fail to meet the minimum 50 mm water seal height requirement specified by DIN 1986-100.

Innovation Solution

A drain fitting design featuring a bypass that reduces negative pressure by creating a temporary air-permeable connection between the drain connector and the environment, preventing sealing water from falling below the critical level, and incorporating a cup-shaped container with a dip tube and flange-shaped inlet section for efficient odor trapping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sealing water height is increased to 50 mm as required by DIN 1986-100, then the odor trap reliability is improved, but the overall height of the drain fitting increases

Engineering Contradiction:
Improveodor trap reliabilityVSAvoidoverall height of drain fitting
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The bypass acts as an intermediary pressure equalization path between the drain line and the sealing water chamber. When negative pressure occurs in the drain line, the bypass opens to allow air to enter, equalizing the pressure and preventing the sealing water from being sucked down. This mediator mechanism protects the sealing water level without requiring increased water height, thus maintaining odor trap reliability while keeping the overall fitting height compact.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically changes the pressure parameter in the sealing water chamber by opening the bypass when negative pressure is detected. This parameter change (pressure equalization) prevents the sealing water level from dropping, allowing the system to maintain reliable odor trapping with a reduced static water seal height of 30 mm instead of the conventional 50 mm.

Inventive Principle:
Principle #35Parameter changes

2Length of stationary object

If the sealing water height is reduced for compact installations, then the overall height of the drain fitting is reduced, but the odor trap reliability deteriorates due to negative pressure sucking down the sealing water

Engineering Contradiction:
Improveoverall height of drain fittingVSAvoidodor trap reliability
Core Design Contradiction:
Length of stationary objectVSReliability

Solution Approach 1:

The bypass serves as a pressure equalization intermediary that activates when negative pressure occurs. It allows air to enter the sealing water chamber, preventing the pressure differential that would otherwise suck the sealing water down. This protects the reduced 30 mm water seal from collapsing, maintaining odor trap reliability despite the compact height.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The bypass provides preliminary anti-action by preemptively equalizing pressure before the sealing water level can drop significantly. When negative pressure is detected, the bypass opens to counteract the suction effect, preventing the harmful action of water level reduction before it can compromise the odor trap function.

Inventive Principle:
Principle #9Preliminary anti-action

3Device complexity

If a conventional odor trap design without bypass is used, then the device complexity is reduced, but the sealing water level becomes unstable under negative pressure conditions

Engineering Contradiction:
Improveodor trap structureVSAvoidsealing water level stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The bypass is a relatively simple intermediary component that adds minimal structural complexity. It functions as a pressure relief path that opens under negative pressure conditions, allowing air to enter and stabilize the sealing water level. This simple mediator structure effectively prevents water level instability without requiring complex mechanical or electronic control systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The bypass introduces dynamic behavior to the otherwise static odor trap system. The bypass opening and closing based on pressure conditions allows the system to adapt to varying pressure environments, maintaining sealing water level stability dynamically rather than relying on a fixed static design that would fail under negative pressure.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Ensures a reliable odor trap function even under extraordinary suction effects, allowing for lower sealing water heights and compact, low-height installations while maintaining effective odor prevention.

Implementation Method 1

when a certain negative pressure occurring in the discharge nozzle is exceeded, it causes a reduction in the negative pressure

Methodology Applied
Scientific EffectNegative pressure: Pressure Gradient

Implementation Method 2

causes a reduction in the negative pressure, as a result of which the sealing water does not drop below a level

Methodology Applied
Scientific EffectPressure equalization: Pressure Gradient

Implementation Method 3

The sealing water of an odor trap forms a gas barrier that prevents unpleasant odors from the drain pipe connected to the drain fitting from getting into the building space

Methodology Applied
Scientific EffectGas barrier:

Implementation Method 4

The effective function of this odor trap requires that the dip tube is always immersed in the sealing water retained in the cup-shaped container

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Data Source

PatentEP3567169B1Drainage fitting
Publication Date: 2021.06.30 VIEGA TECHNOLOGY GMBH & CO KG
  • EP3567169B1 patent drawingFigure 1~2
  • EP3567169B1 patent drawingFigure 3~4
  • EP3567169B1 patent drawingFigure 5~6

AI summary

The invention relates to a drain assembly, particularly as a floor drain or for a shower or bathtub, comprising a housing (4) having at least one inlet opening (6) and at least one outlet spigot (10), which includes a trap (16, 24) designed to hold water seal. To ensure that such a drain assembly has a reliable water seal, the invention is characterized by a bypass (30) which is closed at normal pressure and is designed such that, when a certain negative pressure occurs in the outlet spigot (10) is exceeded, it reduces the negative pressure, preventing the water seal from falling below a level at which the trap (16, 24) loses its sealing effect.