Coating Valve Piston-Rod Venting for Internal Leak Discharge

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Solution Overview

Problem

Current coating product application systems face issues with valve leaks causing paint residue to clog vents, leading to maintenance problems and increased costs due to the need for external venting systems.

Innovation Solution

A valve design with an internal vent pipe integrated into the piston rod, allowing leaks to be directed to open air, eliminating the need for external vents and reducing maintenance by enabling easy replacement of the valve.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an external vent is used to direct leaked paint outside the sprayer, then the control air circuit is protected, but the vent can become clogged with dried paint residue causing maintenance problems

Engineering Contradiction:
Improveprotection of control air circuitVSAvoidmaintenance of vent
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The venting function is extracted from the external sprayer body and integrated into the valve assembly itself. The piston rod now contains an internal passage that directs leaked paint away from the control air circuit and expels it through a dedicated outlet on the valve body, eliminating the external vent channel that was prone to clogging.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The piston rod serves as an intermediary element that captures leaked paint between the dynamic seal and the control air circuit. Its internal passage acts as a mediator to transport the leaked paint away from sensitive areas and expel it through a controlled outlet, preventing both circuit contamination and vent clogging.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Difficulty of detecting and measuring

If a hole is made in the valve body to direct paint outside, then leaking can be detected, but the venting system becomes complex with multiple holes and counterbores

Engineering Contradiction:
Improvedetection of valve leakVSAvoidventing system structure
Core Design Contradiction:
Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The venting function is merged with the piston rod structure itself. The piston rod contains an internal passage that serves both as a structural component and as the venting channel, eliminating the need for separate holes and counterbores in the valve body. This integration simplifies the overall venting system while maintaining leak detection capability.

Inventive Principle:
Principle #5Merging (Combining)

3Object-generated harmful factors

If the vent is located in the sprayer body, then paint leakage can be directed outside, but maintenance operations become more frequent due to vent blockages

Engineering Contradiction:
Improvepaint leakage controlVSAvoidmaintenance frequency
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

The valve assembly, containing the piston rod with its internal venting passage, functions as a disposable or easily replaceable unit. When the dynamic seal wears and causes leakage, the entire valve assembly can be quickly replaced without complex vent cleaning operations, reducing maintenance downtime and improving productivity.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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

This design prevents blockages in the application system, reduces maintenance operations, and lowers overall costs by containing leaks internally, thus avoiding damage to the system.

Implementation Method 1

a part of the chamber being intended to be filled with a pressurized control fluid so as to obtain, against the force of a spring housed in the body, the displacement of the piston

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

against the force of a spring housed in the body, the displacement of the piston

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

a first sealing device formed by a dynamic seal housed in the body around the piston rod

Methodology Applied
Scientific EffectDynamic sealing:

Implementation Method 4

a vent pipe provided in the piston rod and communicating with the internal central orifice between the first sealing device and the second sealing device and opening out into the open air

Methodology Applied
Scientific EffectGravity-driven flow: Gravitation

Data Source

PatentEP3785803B1Valve and system for applying a coating product comprising such a valve
Publication Date: 2022.03.16 EXEL INDUSTRIES
  • EP3785803B1 patent drawingFigure 1
  • EP3785803B1 patent drawingFigure 2
  • EP3785803B1 patent drawingFigure 3

AI summary

This valve (4) comprises a body (8) having an internal central orifice (10) and a chamber (12), the valve also comprising a piston (24) formed by a rod (240) and a piston head (242) mounted in the chamber (12), the rod (240) extending out of the body (8) and being intended to move in a bore (6) of the application system (2). The valve includes a first sealing device (26) housed in the body (8) around the piston rod (240) on one side of the valve where the piston rod extends out of the body (8), a portion (12A) of the chamber (12) being intended to be filled with a pressurized control fluid (F2) so as to obtain, against the force of a spring (34) housed in the body (8), the displacement (F3) of the piston (24). The valve includes a second sealing device (38) housed in the body (8) around the piston rod (240) between the first sealing device (26) and the chamber (12).The valve includes a vent conduit (40) provided in the piston rod (240) and communicating with the internal central orifice (10) between the first sealing device (26) and the second sealing device (38) and opening to the open air or into a portion (12B) of the chamber (12) communicating with the open air.