Adjustable pressure relief valve

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Solution Overview

Problem

Existing pressure relief valves in heating devices with closed circuits lack the ability to accurately adjust the nominal opening pressure without replacing the calibrated spring, leading to inaccuracies due to spring tolerances.

Innovation Solution

An adjustable pressure relief valve with a two-part closing assembly, comprising an upper cap with a thread to compress the spring and a lower cap with a stop, allows for precise adjustment of the nominal opening pressure by turning the upper cap, while an anti-friction pad protects the diaphragm, and a lever mechanism ensures the assembly remains fixed in place.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a calibrated spring is used to maintain valve closure, then the valve can be kept closed under normal operating pressure, but the opening pressure cannot be adjusted without replacing the spring due to manufacturing tolerances

Engineering Contradiction:
Improveopening pressure setting accuracyVSAvoidvalve structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The closing assembly is divided into two separate parts: a upper cap with external threads and a lower cap with internal threads. This segmentation allows independent adjustment of the upper cap to compress the spring and set the opening pressure, while the lower cap remains fixed to the valve body. The segmentation enables pressure adjustment without replacing the spring or redesigning the entire valve structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The upper cap is made adjustable through external threading, allowing dynamic modification of the spring compression and opening pressure setting. This dynamic adjustment capability transforms a static calibrated spring system into a可调 system, enabling precise pressure setting while maintaining the simplicity of the overall valve structure.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the closing cap is made unbreakable by mounting a relief mechanism, then the valve complies with safety standards, but the cap cannot be removed for adjustment or maintenance

Engineering Contradiction:
Improvesafety complianceVSAvoidmaintenance accessibility
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The closing assembly is segmented into an upper cap and a lower cap, allowing the lower cap to remain fixed for safety compliance while the upper cap can be independently adjusted or removed for maintenance. This segmentation resolves the conflict between making the cap unbreakable for safety and allowing access for adjustment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The adjustment function is extracted from the main closing cap structure and placed in a separate upper cap assembly. This allows the main lower cap to remain fixed and unbreakable for safety compliance, while the removable upper cap provides access for pressure adjustment and maintenance activities.

Inventive Principle:
Principle #2Taking out (Extraction)

3Device complexity

If a single-piece closing cap is used to press the diaphragm, then the assembly is simple, but the diaphragm may be damaged during tightening due to excessive force concentration

Engineering Contradiction:
Improveclosing assembly structureVSAvoiddiaphragm protection
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The closing assembly is divided into upper and lower caps, with the lower cap serving as a fixed mounting point and the upper cap providing adjustable compression. This segmentation distributes the tightening force more evenly and allows controlled compression, preventing excessive force concentration that could damage the diaphragm while maintaining structural simplicity.

Inventive Principle:
Principle #1Segmentation

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

Enables fine adjustment of the nominal pressure without replacing the spring, ensuring accurate setting and preventing damage to the diaphragm, thus enhancing the precision and durability of the valve.

Implementation Method 1

a piston (8) movably arranged in the valve chamber, on which there is a calibrated spring (5) and a flexible closing diaphragm (4) arranged. In the normal state, when the calibrated spring (5) is pressing on the flexible closing diaphragm (4), the valve is closed

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The upper cap (9) is equipped with a thread (13) to compress the spring (5). Spring compression can be finely adjusted by turning the upper cap (9) and engaging the spring compression thread (13).

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 3

An anti-friction pad (7) prevents damage to the diaphragm (4) when tightening the cap to the required torque.

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4141304B1Adjustable pressure relief valve
Publication Date: 2025.07.09 VAILLANT GMBH(DE)
  • EP4141304B1 patent drawingFigure 1
  • EP4141304B1 patent drawingFigure 2

AI summary

An adjustable pressure relief valve, intended for heating devices with a closed circuit of a heating medium, with a valve body equipped with a valve inlet and a valve outlet connected to a valve chamber, with a piston movably arranged in the valve chamber, on which there is a calibrated spring and a flexible closing diaphragm arranged, wherein the valve is closed in the normal state under the pressure of the calibrated spring on the flexible closing diaphragm, characterized in that the valve is equipped with a two-part closing assembly, including an upper cap (9) and a lower cap (10) for accurate setting of the nominal opening pressure.