Nested Valve Stem Position Sensing for Cleaning Seat-Lift Verification

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Solution Overview

Problem

Existing valve arrangements lack efficient, accurate, and secure methods for detecting and verifying the functionality of seat-lift functions, particularly in ensuring proper cleaning operations.

Innovation Solution

A valve arrangement with a control unit, actuator arrangement, and flow control arrangement, where the actuator arrangement includes a first and second valve stem, with the second stem extending inside the first and into the control unit, allowing the control unit to detect the position of the second stem, thereby indirectly detecting the movement of the first stem, facilitating secure and efficient detection of cleaning positions without external sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If external sensors are used to detect valve functions, then detection capability is improved, but device complexity and maintenance requirements increase

Engineering Contradiction:
Improvedetection capabilityVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The valve stem itself serves as the detection element by extending into the control unit to directly provide position information. This self-service approach eliminates the need for separate external sensors, thereby maintaining detection capability while reducing device complexity and maintenance requirements.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The valve stem performs dual functions: it mechanically controls the valve member position and simultaneously serves as a position detection element by extending into the control unit. This multi-functionality consolidates components and reduces overall system complexity while maintaining accurate detection.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If external sensors are installed on the valve, then detection accuracy is improved, but maintenance requirements and costs increase

Engineering Contradiction:
Improvedetection accuracyVSAvoidmaintenance requirements
Core Design Contradiction:
Measurement precisionVSEase of repair

Solution Approach 1:

The valve stem directly provides position information to the control unit by extending into it, eliminating the need for external sensors that require maintenance. This self-service mechanism ensures accurate detection while reducing maintenance requirements and costs.

Inventive Principle:
Principle #25Self-service

3Reliability

If the second valve stem extends into the control unit, then detection reliability is improved, but actuator arrangement complexity increases

Engineering Contradiction:
Improvedetection reliabilityVSAvoidactuator arrangement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control unit and actuator arrangement are merged by having the second valve stem extend directly into the control unit. This integration allows the valve stem to directly provide position information, improving detection reliability while the combined structure reduces overall actuator arrangement complexity.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4356028B1Valve arrangement, actuator arrangment and methods of detecting a first position therein
Publication Date: 2025.09.24 ALFA LAVAL CORP AB
  • EP4356028B1 patent drawingFigure 1
  • EP4356028B1 patent drawingFigure 2
  • EP4356028B1 patent drawingFigure 3A~3B

AI summary

A valve arrangement, an actuator arrangement (30) and related methods, in which a first cleaning position (CP1) is detected by mechanically transfer at least a portion of a movement of, or provided to, a first valve stem (31) into a first movement of a second valve stem (32), such that a second valve member is moved towards a first conduit while the second valve member still sealingly engages a second valve seat, whereby a movement of a first valve member is detectable by a control unit by detection of the first movement of the second valve stem in a direction (L') which extends towards the control unit.